Writing Scientific Papers in Astronomy

Astronomy Education Journal, 2021, 1–13

doi: xx.xxxx/xxxx

R E S E A R C H A R T I C L E

Johan H. Knapen

1, 2

, Nushkia Chamba

3¶

and Diane Black

4¶

Instituto de Astrofísica de Canarias, Calle Vía Láctea S/N, E-38205 La Laguna, Spain and

Departamento de

Astrofísica, Universidad de La Laguna, E-38200 La Laguna, Spain and

The Oskar Klein Centre, Department of

Astronomy, Stockholm University, AlbaNova, SE-10691 Stockholm, Sweden and

Free-lance English coach,

Groningen, The Netherlands

[email protected]

Contributed equally

Abstract

Writing is a vital component of a modern career in astronomical research. Very few researchers, however, receive any

training in how to produce high-quality written work in an efficient manner. We present a step-by-step guide to writing

in astronomy. We concentrate on how to write scientific papers, and address various aspects including how to

crystallise the ideas that underlie the research project, and how the paper is constructed considering the audience and

the chosen journal. We also describe a number of grammar and spelling issues that often cause trouble to writers,

including some that are particularly hard to master for non-native English speakers. This paper is aimed primarily at

Master’s and PhD level students who are presented with the daunting task of writing their first scientific paper, but

more senior researchers or writing instructors may well find the ideas presented here useful.

Key words: Science writing; publishing

1 Introduction

Writing papers is key to sharing your research results and ad-

vancing your career. Yet most scientists, including astronomers,

never receive much training in academic writing. They may con-

sider that writing is not important, or chose a career in the sci-

ences to avoid a focus on language and writing skills. To com-

plicate matters, many astronomers are not native speakers of

English, so writing a research paper may become a real strug-

gle.

There are numerous books and papers to provide guidance

to young writers. Several examples, mainly focussed on biomed-

ical and engineering research, are Ashby (2005), Sterk and

Rabe (2008), the Clinical Chemistry Guide to Scientific Writ-

ing

, or G. Gopen and J. Swan’s The Science of Scientific Writ-

ing

. Saramäki (2018) and the related series of blog posts

pro-

vide many tips for writing papers as well as Master’s and PhD

theses, though more specific to the field of computer science.

These publications cover the whole writing process from plan-

ning the paper to final editing and polishing, but do not com-

pletely meet the needs of astronomy students. Resources fo-

cussed on astronomy include a series of book chapters, unfor-

tunately not freely available, covering in great detail the writing

process, graphics, and ethics (Sterken, 2011a,b,c), and a recent

handbook aimed at undergraduate and graduate students (Ste-

vance, 2021).

1 https://www.aacc.org/science- an d- research/clinical-chemistry/

clinical-chemistry%C2%A0guide-to-scientific-writing

2 https://www.americanscientist.org/blog/the-long-view/

the-science-of-scientific-writing

3 https://jarisaramaki.fi/

Compiled on: October 13, 2021.

Draft manuscript prepared by the author.

arXiv:2110.05503v1 [astro-ph.IM] 11 Oct 2021

Astronomy Education Journal, 2021, Vol. 00, No. 0

The main objective of the current paper is to provide concise

guidelines for scientific writing in astronomy for beginners all

over the world, published under open access. Our target audi-

ence consists of Master’s and PhD students, but the material

may also be of interest to astronomers who are more experi-

enced writers, or to writing instructors. The information here

is based on writing classes given to graduate students by JHK

and DB, as well as on the experiences of a young writer (NC).

In this paper, we first describe various aspects of getting

ready to write your paper, including how you can convince your-

self to put words on paper, and where and how we publish pa-

pers in astronomy. We then discuss how the various sections

and parts of a paper can collectively bring your message across.

We conclude by giving a series of hands-on tips on how to write

in correct English, specifically highlighting astronomy-related

examples.

2 Developing the Idea: From Thinking

to Paper Outline

2.1 Think Before you Write

Before students write their first paper, they may be asked to

write a summary or abstract of their research project for de-

partmental reports or submission to a scientific conference. In

the experience of NC, writing an abstract for a conference was

one of the very first encounters she had with a scientific writing

assignment as a graduate student. However, what she wrote

about in her first draft was a summary of the methodology she

was developing for her project (as that is what she spent her

days working on) rather than the main scientific question her

project was meant to address and what preliminary result was

expected or achieved thus far in the analysis. She was absolutely

surprised when one of her thesis advisors returned a completely

different abstract as commentary on her draft, which made her

think to herself, ’Oh is that the whole point my project?!’ This is

one of many experiences that has led us and other writers (e.g.

Sterk and Rabe, 2008) to identify the first golden rule on scien-

tific writing: think before you write.

For instance, to write the Introduction section of a paper

(Sect. 5.5), you require knowledge of the literature, a recog-

nition of the primary and secondary sources needed to place

your project in the astrophysical context, the gap in the litera-

ture that your project aims to fill and how the content in the

paper is an important step towards filling this gap (e.g. Is it a

new, efficient method? Have you acquired higher-quality data

on an astronomical source?). Collecting all these resources to

place your project in the broader context of the field is ’thinking

before writing’. Of course, the thinking needed for each section

of the paper will be different and may require feedback from

co-authors (consider for example how you think about the in-

terpretation of your results for the discussion section; Sect. 5.8).

When gathering background resources, students also need

to read and think critically. Critical reading, thinking and writing

are academic practices that many astronomy students may not

be familiar with or have never encountered during their educa-

tion as not all programmes offer such courses. To these read-

ers, it is important to understand that to be critical of an idea or

paper does not necessarily mean to be negative. The Oxford

Learner’s Dictionaries

defines critical also as ’involving mak-

ing fair, careful judgments about the good and bad qualities of

someone or something’; in other words, to evaluate the validity

of an idea and question when it may or may not hold true. Obvi-

4 https://www.oxfordlearnersdictionaries.com/definition/american_

english/critical

ously, readers can be critical about an idea only if they have suf-

ficient knowledge

or expertise about the subject in question.

Even more problematic is that many first year PhD students

struggle to read scientific papers. This is not only because the

style of scientific writing is very different from novels or popular

articles, but very few scientific papers are written well enough

for non-experts or students to follow them easily.

We suggest a number of useful tips that new writers in as-

tronomy may find helpful when reading the literature. These

guidelines are adapted to astronomy from Wallace and Wray

(2021, mainly Chapter 4) and may help students skim through

papers in an efficient manner to identify which articles could be

most relevant to their field of study.

i. Think about why you are reading this paper. Are you look-

ing for an answer to a specific research question? Or evidence

to support an assumption used in your study? Write down a

list of questions or expectations for your literature review even

before you start reading papers.

ii. Why did the authors write this paper? Read the title and

abstract first—do they raise more questions than answers to

your initial questions? This is completely normal as authors

cannot include all the information in a title and abstract. An-

notating the abstract as you read it could help you highlight

which sections of the paper would be most relevant to your

study and determine whether you need to skim through the

introduction to determine the main aim of the paper.

iii. Study the figures of the paper and read the captions—

what story do they tell you?

iv. What are the main conclusions of the paper? In astronomy,

the main claims of the authors can usually be found in the con-

clusions section. Are these claims warranted by the evidence

presented in the figures? If not, why not?

v. Finally, what use is this paper to you? Go back to point 1

and think about how this paper could be a resource to your

own work—does the paper require an in-depth reading?

2.2 Use your own Thinking Style

Some people think primarily in pictures, while others think pri-

marily in words (Nishimura et al., 2015). Over many years of

teaching we have seen that some people need to draw pic-

tures and diagrams to explain a point—these are visual thinkers.

When visual thinkers pick up a new publication, they look first

at the figures and graphs. Other people tend to talk through

problems, and may like to write words and text to think things

through. These verbal thinkers pick up a new publication and

start reading the text to learn what the paper is about. We have

had students who think in terms of graphs, perhaps a varia-

tion on thinking in pictures, and others that tended to focus on

sounds, colours, or moving processes (the latter are really good

at solving a Rubik’s cube). Yet others may immediately see the

solution to maths problems but cannot easily verbalise why.

So what does thinking style have to do with writing? Under-

standing how you and your co-authors think may help you in

planning your paper. People who think in pictures may like to

plan the paper with flow charts, colours, and arrows—later turn-

ing these images into words (Ashby, 2005). On the other hand

verbal thinkers may prefer making a classical outline or using

bullet points to plan the paper. Understanding that your col-

leagues may have a different thinking style may help avoid con-

flicts in writing. If for example your supervisor says you must be-

gin by making an outline, but that does not work for you, then

5 But what does it mean to have knowledge on a subject? It turns out that

this is a major philosophical question (e.g. Chrisman et al., 2016, Chapter

2), so do not worry!

Knapen, Chamba & Black

explain that you work better with coloured flow charts or per-

haps make your flow chart and use that as a step in developing

an outline that your supervisor and co-authors can understand.

2.3 Learning to Write

Construct your paper carefully, as if producing a painting by

starting out with a rough sketch and then filling in the details.

Do not start off by sitting down with a blank sheet of paper or

newly opened file, and pretend you will simply start writing at

the beginning and keep writing until the end. Even the best

writers find this almost impossible to do.

The following would be our idea of writing a paper, from start

to submission:

• The single most important item to consider before you even

start writing is to define the message you want to convey

to the reader, and what story you want to tell. Define that

clearly, and writing will become possible. Fail to define that

and you will struggle.

• Second, draft the title and abstract of your paper.

• Third, on a blank sheet of paper, or a whiteboard, or in a

computer file, brainstorm and sketch out how your paper

will look. As we discussed in Sect. 2.2, your personal pref-

erence will steer you towards creating an outline with words,

pictures, or colours.

• Fourth, define your sections and subsections and then add

the key figures and tables that you want to include in the

right place. Draft the captions.

• Fifth, add paragraphs, identified by their contents and by

what you need to say.

• Sixth, fill in the paragraphs and (sub)sections with a very

rough and quickly written first draft of the text. You may

want to start with the easiest sections (usually sample, data,

methods) and leave the hardest for later (discussion).

• Seventh, edit.

• Eighth, edit more.

• Ninth, tenth, ...etc. More and more and more editing and

polishing (including incorporating comments from others).

Don’t be afraid to delete!

• Last and extremely important step: decide that enough is

enough, or run up against a deadline, and submit your pa-

per.

Start each bit of your paper like a Sister Sledge song: start

off with the main message. Start each section and subsection

with a sentence on what you are going to write and why, then

write it, and sometimes you can even end it with a concluding

sentence summarizing what you just wrote.

Very rarely does a writer write the perfect text in a first draft.

Often the most productive writers write very quick and sloppy

first drafts, and then edit and edit and edit. Usually a deadline

rather than having reached perfection determines when your

paper is finished. If you are not sure about a fact or figure, do

not let this slow down the writing. Just make a note to yourself

to add the missing bit of information later.

Always ask others to read your work before you submit it.

Do not wait until you have a perfect near-final version, but

share early drafts to collect early feedback. Apart from your co-

authors, you can ask supervisors, or colleagues, or friends, or

family members to read your draft. If you are unsure about a

certain aspect, ask them explicitly to check that (spelling, gram-

mar, maths, literature completeness, etc.).

3 Choice of Journal and Submission Pro-

cess

3.1 Where to Submit?

You may be invited to submit a research paper, for instance to

include in the proceedings of a conference you have attended,

or to contribute an invited paper. If you are not invited, however,

you and your co-authors will need to decide where to submit

your manuscript. Some general guidelines to help you are as

follows.

• Consider the field, scope and readership of the journal, mak-

ing sure your paper ’fits’.

• Check the author’s instructions of ’your’ journal to make sure

you can submit your paper.

• For your career development, refereed professional journals

are best.

• Impact is important: a well-known ’famous’ journal is better

than less-known ones (see Box 1, below, for impact factor).

• Aim as high as is reasonable. For astronomy research papers,

this means a small list of ’main’ journals which include the

Monthly Notices of the Royal Astronomical Society (MNRAS),

Astronomy & Astrophysics (A&A), the Astrophysical Journal

(ApJ), the Astronomical Journal (AJ), Icarus, and Nature As-

tronomy. Many of these journals will ask you to pay page

charges, but you can request that they be waived if you have

no funds. Do ask before submitting your manuscript, not af-

ter it has been refereed!

• Do not decide a priori that a certain journal will not accept

your paper. Let the editor and referee accept at such a deci-

sion. Ask advice from more experienced researchers before

submitting your paper if you are not sure.

• There are many other refereed journals, including open-

access ones, but most do not have the same impact as the

main journals and may not make the same impression on

your CV. Many are commercial so check any costs before

agreeing to publish. Some journals are even considered

’predatory’ (Eriksson and Helgesson, 2017).

• Once you and your co-authors have made a choice, follow

the author’s instructions to produce your manuscript for

submission.

• If a paper is rejected, analyse why (ask your co-authors or

other colleagues with more experience) and if you do not

agree with the decision consider submitting a revised ver-

sion of your paper to the same journal, or to another journal.

6 We know of a case where a research group had submitted to a real journal,

then received a message from a predatory one with a similar name, and

almost got tricked into sending their final version to the wrong place.

Astronomy Education Journal, 2021, Vol. 00, No. 0

Box 1: On Impact Factors and Citations

Journals have impact factors, but the impact of individual re-

searchers or papers is measured through citations.

A journal’s impact factor is the yearly average number of cita-

tions of articles published in the journal in the last two years.

For journals like Nature it is very high (over 40) but due to a

few very highly cited papers, often in other fields (mainly in

the life sciences). For the main astronomy journals it is of or-

der 5. For smaller journals, at or below 1.

You can count the number of citations to any given paper

(also provided by the Astrophysics Data System, ADS

). For

an individual researcher, you can count the total number of

citations, or those to first-author papers, or the number of

well-cited papers (the h-index is the number of papers, x, with

more than x citations). ADS provides all this information and

more. Remember that total citations are often driven by pa-

pers with many authors, and that the h-index tends to in-

crease with the age of the scientist.

3.2 Co-author Complications

Single-author papers are rare in modern astronomical research.

The first author is often the person who has done most of the

work, by some integrated measurement. In large collaborations,

author lists are sometimes alphabetical and the person who

can claim most authorship may in that case be identified as ’cor-

responding author’. In many fields the last position in an author

list is an honorary one, often given to a key senior colleague. In

astronomy, however, this person would be second or third in

the list. As evaluations for jobs, promotions, grant competitions,

etc. normally consider first positions on an author list (and sec-

ond and third to some extent), it is important that you explain in

your CV or application materials what your role has been if you

were not first (2nd, 3rd) author—and that you ask your referees

to confirm this in their letters.

Co-authors are typically those who made substantial contri-

butions to a paper. They can include colleagues who had the

original idea or developed the instrumentation or code, or put

the funding in place. People who only were on, e.g., the ob-

serving proposal or provided limited assistance during an ob-

serving run typically are acknowledged rather than made co-

author. Co-authorships are sometimes offered to students by

researchers outside their supervisory team, for instance where

the student has in some way contributed to the paper, or forms

part of a larger collaboration.

When writing your own paper, and as there are no accepted

rules for who will become a co-author, as a junior scientist you

should not unilaterally remove prospective co-authors unless

you particularly fancy interpersonal conflict. If you have doubts,

ask a senior colleague for advice. Many papers have co-authors

who have done little, and who probably should merely have

been acknowledged. On the other hand, people may have

made key contributions to a project at an earlier stage, which

are not visible to latecomers but remain vital. As it is such a grey

area and people may hold strong views, it is best to accept as

a fact of life that every now and then a person becomes your

co-author who you would personally not have given that much

glory.

3.3 On Names an d Numbers

It is a good idea to consider how you want to be known in

the scientific world before you submit your first paper. Names

are much affected by local culture. For instance, Chinese na-

7 https://ui.adsabs.harvard.edu/

tionals and many others start their name with what in English

would be the last name, followed by their first (or given, or fore-

) name(s). In Spain and other countries, people have two last

names, their father’s (first) last name traditionally followed by

their mother’s. In Portugal, two last names are also used, but

the mother’s traditionally comes first. If you have more than one

first name, or a middle name, you may wish to add the name,

or its first initial (as current author JHK does). Americans some-

times wish to maintain ’the third’ or other annotations as part

of their name. Some female scientists prefer to sign with initials

rather than first names so they are not immediately identified

as female (current authors NC and DB do not). In some regions,

people only have one name (they are mononymous) and not all

editors and publishers are ready to accept this.

You should consider the conventions in our field along with

your own preference when choosing how you will be named

in scientific publications. Citations are key, and it is important

that your papers be readily identified with you. Decide which

name(s) to use and which additional initials or other signs to

maintain. If the first name you are known by does not corre-

spond with your initials, be careful and at least consistent in

how you publish your name. Spanish speakers often hyphenate

their two last names to avoid being cited with their second last

name only (the first last name being considered a middle name,

or second first name!). Some journals now allow authors to add

their name in Chinese, Japanese or Korean characters after the

English version of their name. Another positive novelty is that

several journals now allow authors to change their names (for

reasons including gender identity, marriage, divorce, or change

of religion).

This may look messy, and it is. It is sometimes impossible to

find a reliable overview of a person’s papers because they, for

instance, are inconsistent in how they are referred to as authors,

have a common name, or have changed their name. For all

these reasons and many more, we recommend that all authors

to obtain a free persistent digital identi-

fier (ORCID iD) which is basically a number that is tied to your

person. By coupling your professional information, papers but

also affiliations, grants, etc., with your ORCID iD, all your prod-

ucts can be identified as yours even if searching by your name

does not yield unique or conclusive results.

3.4 L

In astronomy, as in much of physics and engineering, L

X is

used to prepare manuscripts. L

X is a software system for

document preparation which offers significant advantages over

word processors such as LibreOffice Writer, Microsoft Word, or

Apple Pages. For instance, L

X is free software distributed un-

der a public license, a L

X document is prepared in plain text

rather than an often proprietary internal format, and L

X is ex-

cellent at typesetting mathematical expressions (as well as non-

Latin scripts).

Most journals provide their own L

X macro packages to pre-

pare manuscripts. Many text editors and software packages are

freely available for all main computing platforms. Overleaf

increasingly used as an online tool to allow multiple co-authors

to share the editing of a L

X document.

As you start out in astronomy, it is worth investing time and

effort to master at least the basics of L

X. You will need it in

professional astronomy. And as you start putting your paper

together, if you use the L

X macro package of your favourite

journal your manuscript will immediately start to look ’real’!

8 https://orcid.org/

9 http://www.overleaf.com/

Knapen, Chamba & Black

3.5 Roles of Referee, Editor, and Language Editor

You write your paper, typeset it to perfection using L

X, and

submit it to the journal. A scientific editor will consider your

manuscript and decide whether it might be suitable for pub-

lication in their journal. An editor is usually a senior scientist

and a subject specialist. They will send your manuscript to a

referee (in astronomy, usually only one, in related fields, up to

five) for peer review. The referee is a colleague who is a special-

ist in the topic of the paper. They will write a report containing

a recommendation to the editor and suggestions for improve-

ment to the authors. The role of a referee is to make sure the

paper is technically sound, but the referee is not a co-author of

the paper. A referee can thus recommend acceptance without

agreeing with everything written in a paper.

In astronomy, most referees are supportive, and after au-

thors submit a revised version of their manuscript taking into

account the recommendations of the referee, most papers are

accepted for publication. Sometimes multiple rounds of refer-

eeing and revision are needed, sometimes a second referee is

sought to adjudicate in a stalemate situation, and sometimes

a paper is rejected. When dealing with difficult referee reports,

is it always a good idea to consult with more experienced col-

leagues. Bertout and Schneider (2004) provide more back-

ground information on the roles of editors and referees at the

journal Astronomy & Astrophysics (A&A).

Once a referee recommends acceptance and the editor in-

deed accepts your paper, it will enter the production stage. A

language editor will typically proofread your manuscript and

make changes to perfect both English usage and compliance

with the journal or publisher house style. Language editors are

usually very good at their job, but they are not astronomers. So if

you are asked to check the page proofs (and answer any queries

a language editor may have identified) it is very important to

check your paper line by line, word by word, to make sure no in-

advertent changes have been made. As the language editor’s

changes are usually identified, this is also a learning opportunity

to see where your phrasing or typesetting was not optimal. A&A

has an instructive list

of things that their language editors of-

ten need to correct, which is well worth looking through.

At the page proof stage you can still make small changes

or additions if absolutely necessary (such as including a miss-

ing reference that has been pointed out to you after you pre-

published your paper on the preprint server ArXiV). After that,

the paper is typeset, gets a formal journal reference, and is pub-

lished. It is indexed and will form part of the body of scientific

literature—in perpetuity!

4 Basic Points on Writing Style

Before writing a manuscript, it is important to define WHAT you

are going to write, and HOW (Sect. 2). A refereed research paper

is very different from an outreach article. A first key question

to consider is the language. In professional astronomy, this is

almost always English, but in particular for outreach (but also

some grant proposals and job applications) it may be another

language. Writing in English means for most of us writing in a

language which is not our own.

The basic concepts to consider are the Audience—who, level

of expertise, what do they know and what do they need to

know?; Purpose—inform (science paper) or entertain (popu-

lar)?; and Tone—objective, neutral, emotional? For scientific pa-

pers in refereed journals, your audience will be professionals in

10 https://www.aanda.org/contacts-bottommenu-162/

69-author-information/language-editing

the field. However, they will not necessarily be experts in your

sub-field, or aware of all the methods, techniques or tools you

use. So explain all the specifics needed to understand your work,

while avoiding jargon on the one hand and explaining the obvi-

ous on the other.

The purpose of a scientific paper is to inform, to describe your

experiment and results in a scientific way. This means that you

give enough detail and references that your results and conclu-

sions can be verified and reproduced. So do not write ’we re-

duced the data in the standard way’ but rather ’we followed the

standard procedures for data reduction as described in detail

by Author et al. (year)’ or ’we reduced the data in the standard

way by first ..., then ... and finally ... .’

The tone to be used is formal. So, for instance, do not use

contractions (use do not, cannot, will not, it is, etc., rather than

don’t, can’t, won’t, it’s), do not address the reader directly in the

imperative (say ’the data are...’ and not ’note that the data are...’),

and avoid colloquialisms and slang, or references to fashionable

popular culture. Section 6.4 contains more tips on sentence

structure.

A formal tone also implies that any criticism of others’ work

should be phrased in professional terms, polite, and without per-

sonal sneers. So instead of the insulting ’X et al. clearly showed

their lack of understanding of the basics of statistics when they

published...’ one could be highly critical but still professional:

’The recent study of X et al. fails to properly account for ... in

their statistical analysis.’.

Finally, it is important to consider how to organize your prod-

uct. In a research paper, we tend to use IMRaD (=Introduction,

Methods, Results and Discussion, see also Sect. 5.4) but a press

release, for instance, is structured very differently. If you are not

sure how your writing style fits the purpose, read similar writ-

ings, or ask more experienced colleagues.

Towards Inclusive Language

In recent years, the field of galaxy formation and evolution has

seen the emergence of a number of terms which in real life

signify violent, highly unpleasant and mostly illegal acts, some-

times with misogynous or racist undertones. Some of these

terms, such as a hierarchical scenario, cannibalism, stripping,

strangulation or starvation, are by now so integrated into the

professional vocabulory that in particular younger scientists

may consider their use ’normal’. We would urge exercising con-

straint in the use of violent terminology, and to consider using

alternatives. Vallejo and Moreno Soto (2018), for instance, sug-

gest more collaborative and inclusive terms to replace the vio-

lent ones, including an ancestral scenario, collectivism, sharing,

collaboration and preservation for the five mentioned above as

examples. You can define these terms when you first use them

in the text to ensure that readers understand what you mean.

5 Step by Step Guide to Writing a Scien-

tific Manuscript

5.1 Title: Clear, Informative, Short

The title is the main marketing tool for your paper—it is hard to

get right but you need a good one to catch a potential reader’s

attention. Ideally, it compresses the entire message of the pa-

per, the ’narrative’, or story, into a maximum of 10 words. The

title needs to match the abstract and the rest of the paper. It

needs to be accurate. Keep the title as short as possible. Use

simple words, no jargon, no abbreviations, no new concepts. In-

clude all important key words (search engines and other index-

ing tools will later on allow others to locate your paper). Avoid

vague titles. Avoid starting with ’On...’ or ’Towards...’ (instead, say

what you’ve done!). Avoid jokes or references to modern culture

Astronomy Education Journal, 2021, Vol. 00, No. 0

which may not age well. If possible, package the main conclu-

sion of your paper into it.

As an exercise, you can take a recent issue of a major journal

and consider what you think of the various paper titles. You do

not need to understand what the papers are about, but can ask

yourself questions like does the title inspire me? Does it inspire

me to read the abstract? Is it silly, or cheesy? Is it so technical, or

long, or complicated, that it puts me off reading further? Then

compare your own draft title(s) with what you have seen.

5.2 Abstract

The abstract sets the scene, identifies the problem, outlines how

you will solve that problem, and then describes what you have

done, how, and what you have concluded (ideally coming back

to ’setting the scene’). In the abstract, you try to tell the whole

story of your paper in ten lines. Bertout and Schneider (2005), at

the time editors of A&A, phrased the importance of an abstract

as follows.

Confronted with a huge volume of new information every week,

researchers in the physical sciences can no longer read all the lit-

erature that is published on scientific matters that interest them.

The paper’s abstract, undoubtedly the most visible part of any sci-

entific article, has therefore in recent years become particularly

important as a filter for deciding what articles are worth taking

the time to read in detail. This is particularly true for astrophysics

articles, since the abstract is referenced and widely accessible in

the NASA Astrophysics Data Service, in topical newsletters, and in

other abstract databases.

Whether a colleague will read your paper or not thus depends

in large measure on the level of interest that is gained from read-

ing your paper’s abstract. When writing it, one must therefore

make sure that it conveys the essential elements of the article to

the reader: its objective, the methods used to reach it, and the

results obtained. This must be done in a concise yet informative

way, without using external references that will not be referenced

in the abstract databases. Finally, the style must be pleasing.

Bertout and Schneider (2005) then propose using so-called

’structured abstracts’, with explicit headings Context, Aims,

Methods, Results, and Conclusions. The journal A&A recom-

mends but does not enforce using a structured abstract, but

even if you do not use it explicitly, make sure you include the

main concepts in your abstract.

A useful exercise is to compare abstracts from different pa-

pers, for instance when you make a literature review (Sect. 2.1).

Which ones call your attention, and invite you to read the pa-

per? How many fail to set the stage and start by telling you

what they did, rather than why? If you do not have the time to

read the whole paper, do you think the abstracts will allow you

to vaguely remember the results later on? Can you recognize a

structure of the kind proposed by Bertout & Schneider?

5.3 Figures and Tables

It is often useful to develop an idea very early on about which

figures and tables will need to be included in the paper. You

will need to find the balance between including all the key ones,

without including too many. Series of figures and tables, as well

as long tables, can be published electronically only, and/or in

an Appendix. As usual, a journal’s instructions for authors will

inform you how to produce your tables and figures.

Figures need to be easy to understand and of high quality.

Try to make them as vector graphics (pdf is vectorial, jpeg is not)

so they can be scaled up. Always deliver figures of the highest

possible quality to the publisher, even if you use smaller versions

for other purposes (e.g. ArXiV or talks). Include all lines, points,

labels, etc. that you need, but omit any that are not strictly nec-

essary. Explain all elements of the figure in the caption. Do not

make your figures too complicated: you want them to catch the

reader’s attention. And try to make your figures tell the story of

the paper: some people will look at the figures in your paper,

or see them in a conference presentation, without reading your

carefully worded text (sometimes even without reading the cap-

tion). Actively looking for the key message in other papers in ti-

tle, abstract, and figure captions can help you try to act like the

audience to your own paper when writing it!

In terms of presentation, use a colour scheme that can be

interpreted by all, including those with colour vision deficiency

(’colour blindness’, affecting up to 10% of your colleagues). Sim-

ple but effective tips include using both line/point style and

colour to distinguish different elements (never only colour), and

using a colour scheme that is appropriate for colour blind peo-

ple. Many resources are available online.

e.g.11,12

You may want

to use the same format for all your figures. And you may want

to end each caption with a one-sentence conclusion of what

the figure shows. That way, if a reader scans the figures of your

paper, or someone tweets your figure, the context and implica-

tions directly come with it.

5.4 Building up your Paper

The typical structure of a research paper in our field is the fol-

lowing: Introduction, Sample/Data/Methodology, Results, Dis-

cussion, Conclusion (IMRaD). Try not to mix these sections. Keep

them logical and as short as you can. Use sub-sections and para-

graphs to separate the text into ’bite-sized chunks’ that can be

digested easily by a reader. Tell the story of the paper, using the

’narrative’ that you have defined before you started writing.

Keep an overall ’hourglass’ shape of the paper in mind: it

starts broadly, with the ’big picture’ first part of the introduc-

tion, then narrows down into the details of methods and results,

before broadening again at the end, when the discussion and

conclusion sections place the new findings in a wider context.

5.5 The Introduction

The Introduction has several roles, which you can use in this or-

der to draft it.

i. Present the problem, in a wide context. The ’Big Picture’.

Example ’topic’ sentences (Sect. 6.1) could start with ’The Sun

is...’ or ’In modern cosmology, ...’

ii. Narrow the focus, by introducing the specific sub-topic you

will be describing, e.g. ’magnetic fields around sunspots...’ or

’galaxy mergers ...’

iii. Point out the gaps in the existing knowledge which you

want to fill in with your work, e.g. ’however, the exact role of...

is unclear’.

iv. Now present what you did in your study, and define the

exact problem tackled. ’The aim of the current study is...’

v. Finally, describe what you have done, ’We therefore ob-

served...’

vi. In many papers the Introduction ends with a preview of

what follows. ’This paper presents...’ or ’we present our sample

in Sect 2...’

A good introduction is concise, focusses on the main issues,

avoids repetition and includes references to relevant work. This

allows the reader to place the work in context, and to find key

background papers if they want to know more. You can also

11 https://jfly.uni-koeln.de/color/index.html

12 https://bconnelly.net/posts/creating_colorblind-friendly_figures/

Knapen, Chamba & Black

introduce other relevant aspects, such as a specific telescope,

instrument, simulation, or survey, or a particular object. Keep it

short and reasonable. Unless you write a full review paper, you

do not need to refer to every paper ever written on the topic.

Use ’e.g.’ and then give the most important or relevant ones, or

cite a review paper. Make sure you include modern work, and

references from the current year. This shows that your research

is relevant and timely. On the other hand, do not only include

modern papers. Almost all work rests on key papers that may

have been published before you were born, but you must be

aware of them (Box 2, below, gives some tips on how to find key

papers in your field). In any case read and check all papers you

cite to make sure they in fact support your claim and do not

assume previous authors have done this.

Consider for what statements you need a reference. Ba-

sically, for textbook-level basic knowledge, no; specific state-

ments or results, yes. Do not be afraid to cite your own relevant

papers, or those of your friends. Do not overdo it either, papers

that only quote own work are bound to have less impact.

Box 2: Finding Key References with ADS

i. Find a modern, well-written, relevant paper by a leading

author or group and open the abstract page in ADS.

ii. In the left column, click ’References’. This shows all the

papers referenced in the paper.

iii. Click ’View this list in a search results page’

iv. Order the resulting list by ’Citation count’ (in the drop-

down menu which says ’Author count’ by default)

v. You can now see the most-cited papers among those

referenced in your selected paper. Many of these will be cat-

alogues, or survey description papers. But very quickly you

can identify papers in the specific field of your study which

are classic and important.

vi. Repeat this process a few times for different modern pa-

pers, and the classic, pioneering, critical papers in the field

will soon bubble up.

vii. Click on one or more of these key papers, and check

which papers cite it. The most recent ones will quickly give

you a superb overview of what is currently going on in the

field!

5.6 Sample, Data, Methods

This is probably both the most boring and technical section of

your paper, and the easiest to write (and often also the first sec-

tion that researchers write). In an observational paper, for in-

stance, you describe what data you used, how you obtained and

reduced them, and what analysis methods you used. Do not de-

scribe the results—that comes in the next section. The most you

do here is show the reduced image (or similar) in a Figure, but

the astrophysical description of what you see comes in the next

section.

The main aims of this section are to allow others to (1) judge

how you reached your results, and how reliable, good, novel, etc.

your data and methods are to the field, and (2) reproduce what

you did. While point 1 is generally straightforward to assess,

point 2 reflects an open issue and ongoing debate in astron-

omy. There are many solutions to make a scientific paper re-

producible, each with their own caveats (see for example the re-

cent work by Akhlaghi et al. (2021) who promote an exactly re-

producible model for papers, from its figures to the underlying

pipelines in the analysis—see also the critique by Kuttel (2021)).

We will not review all currently available solutions to this issue

here, but do point out that it is particularly important to include

all critical details in the paper. Too often when we refer to older

papers it is impossible to reproduce the methodology in detail

because the data or methods were not described well enough,

are unusable, or even not publicly available now (see also Sect.

5.11). Do not hide any caveats of your methods, and be honest—

identify and address either how you have solved these issues or

why they do not affect your results (if possible, in a quantifiable

way). On the other hand, do not describe everything you ever

did, and ignore issues that do not affect the main line of the

paper.

Often in astronomy we repeat methods already described by

others. In that case, a statement such as ’we followed the data

reduction procedures as described by Author et al. (year) ...’ is

appropriate but then do describe anything you did differently.

Even if you follow previous work by your own group (or your-

self) never copy verbatim a previous description of a method

you have followed. This is plagiarism, even if you copy your own

words (in which case it is called self-plagiarism—arguably just

as bad).

In some journals (such as Nature) most of the details of this

sort go into a separate online section ’Supplementary Material’.

Similarly, in other journals you can place non-critical or back-

ground information in an appendix. In either case, make sure

you reference the background material in the main paper. Be

honest, and if there is a significant problem or doubt, do not

bury it in an appendix or in the supplementary material.

Keep the most technical parts in specific subsections or para-

graphs, so a reader can skip them if they want. Finally, we rec-

ommend using the past active tense: ’we used...’ (not ’we use...’

or ’we have used...’), but more important than that is to be con-

sistent: use whatever you choose throughout the Section.

5.7 Results

In astronomical professional writing, this is where you describe

what you have found. There is no need to discuss all the impli-

cations yet, or to make detailed comparisons with other work,

because that will come in the Discussion. But do not be too dog-

matic about this, because if you strictly only report what you see

in this section and leave anything more profound to the discus-

sion section the paper will become hard to read in a logical way.

The results section is illustrated with figures. Select those

first, define (or remind yourself of) your narrative, and use a log-

ical structure by employing sub-sections and paragraphs. Sec-

tion and sub-section titles allow the reader to scan the paper

quickly. As we suggested in Sect. 5.1, keep (sub-)section titles

short but include the key words or even the key message you

want the reader to pick up even if they just scan them and do

not read the actual text.

An effective writing trick is to start each section and sub-

section with a sentence saying why you looked at the particular

aspect you are about to describe. Compare these two ways of

starting: (i) In Figure 3 we plot our data for all the stars in our

sample; and (ii) To demonstrate how parameter x relates to y,

we show the results for all the sample stars in Figure 3. The

second approach clearly leads the reader to look at Figure 3.

5.8 Discussion

This is where we come back to the hourglass shape of the pa-

per (Sect. 5.4). The previous sections, methodology and results,

were very specific and probably very technical. In the discussion,

you place your results in the context of other work, or compare

them to theory, modelling, or observations. The other main aim

of the discussion section (which is really ’critical discussion’) is to

describe the limitations of the results you have just presented.

Once again, use sub-sections with well-chosen titles to

break up your discussion into manageable parts, choose your

paragraphs strategically, and use first sentences to set the

Astronomy Education Journal, 2021, Vol. 00, No. 0

scene. Then include final sentences or paragraphs in each sec-

tion or subsection to summarise the main point.

Some key aspects you can include in the discussion section,

broadening up the ’hourglass’ as you go down the list, are the

following.

1. Repeat why you carried out this study.

2. Return to the main question you posed early on in the ab-

stract, and answer it.

3. Explain how your answer is supported by your data, model,

figures, derivations, results.

4. Discuss how your results, and your answer, relate to other

work in the literature. Say how they are supported, how they

support other work, but also where they disagree.

5. Give your view on why there is disagreement, and/or discuss

any alternative explanations.

6. Add what future work or observations can provide more clar-

ity or advancement.

7. Finally, broaden up to describe wider implications, applica-

tions, and recommendations.

5.9 Conclusions

Always include your conclusions. If you do not make a separate

Conclusion section, then at least call the previous one ’Discus-

sion and Conclusions’ (and make sure you explicitly add the con-

clusions in the text). One of the main reasons for this is that

many readers do not have time to read the whole paper, but

may skip to this section to get a quick overview of what you have

done and found.

Keeping this in mind, start the conclusions section by sum-

marizing very briefly the why, how and what of your paper. Re-

peat key points like what the aim of the study was, the sam-

ple size, with what telescope you observed the objects or which

pipelines or codes you ran, and then make a concise and logical

summary of the main results and how you interpret them. You

may want to refer back to your key figures in the conclusions

section, to tempt those readers who read only this section to

also look at your artwork.

Finish up with a strong concluding sentence. Do not just

say something bland like ’more research is needed’ but try to

summarise your whole paper in one final sentence. Something

like ’our results show how galaxy metallicities confirm...’.

5.10 Acknowledgements, References, Appen-

dices

Acknowledgements are important. This is both in a formal

sense, for instance because your funding agency will insist that

you acknowledge their financial support, and in an informal one,

because you want to record your appreciation of the help you

have received from others—colleagues who helped you with

specific aspects of the work, or friends or family who are not col-

leagues but who for some reason you feel deserve to be thanked

publicly for their role in the work you have managed to com-

plete and publish.

References will need to be included in the form prescribed

in the instructions for authors of the particular journal you

have chosen. Ensure that the references are complete because

their use is to allow others to find the papers. Do not save on

citations—our colleagues are our referees too, and everybody

likes to see their own work referred to by others. Consider

whether you can, or need to, add software or other products

which are not strictly research papers to your formal reference

list. Citations are often needed by the relevant authors or devel-

opers to secure future funding, or to show that their work has

been useful. Where references are not needed or possible, then

add the software or other products to the acknowledgements

section.

Finally, use appendices to include material that would make

the paper too long, or that is necessary but too technical to in-

clude in the main body. Sometimes you can also move addi-

tional tests or explorations to the appendices. As appendices

are almost always published electronically, length restrictions

tend to be either absent or less of an issue.

5.11 Data and Software

A key aspect of ethics in science is that scientists are open about

their work and what they have done, and about the data and

tools they used. So whenever you can, publish your data and/or

your software or code with your paper. Both MNRAS and A&A

have a contract with the CDS

which guarantees long-term

archival. Git

or GitHub

are often used to publish software.

When you publish your software or code, ideally you license

it under a free-software license.

If you do, you grant your col-

leagues the right to ’run, copy, distribute, change and improve’

the software. It is interesting that if you make your software

publicly available but without an explicit licence, it is copyright-

protected under the Berne Convention Implementation Act of

1988 and other astronomers are legally forbidden from copy-

ing the software, modifying it, distributing it, or distributing

a corrected or improved version (as pointed out in the Ethics

Statement of the European Astronomical Society

Avoid making data available through your own website, or

your institute’s, or your research project’s. The websites will dis-

appear with time, or the URLs will change. The only way to guar-

antee that your data or software will remain accessible (even

after you have changed your career path, or have retired) is to

formally publish it in a repository like the CDS.

6 Writing Mechanics for Manuscript De-

velopment

6.1 Paragraphs

Well-structured paragraphs begin by expressing the main idea

in the first sentence (topic sentence), then develop that main

idea with facts, examples, or analysis.

A paragraph can end

when the necessary information has been given, or provide a

summation or linkage to the next idea. A topic sentence may

be very general, for example a galaxy is a group of stars. This

very general sentence could lead to description of the types of

galaxies. Such general sentences are common at the beginning

of an introduction. A topic sentence in a methodology section

could be something like to measure x, we followed several steps.

This topic sentence very obviously leads to a list of steps, prob-

ably using words such as first, next, finally. Topic sentences in

a results section often refer to a figure or table. Table 3 shows

the measurements of xxxx. This sentence would then lead to a

systematic presentation of each result. Paragraphs do not need

a special sentence to end, but sometimes in a results or discus-

sion section, it is helpful to give a conclusion, for example these

13 https://cdsweb.u-strasbg.fr/

14 https://git-scm.com

15 https://github.com

16 http://www.gnu.org/philosophy/free-sw.html.en

17 https://eas.unige.ch//documents/EAS_Ethics_Statement.pdf

18 This structure is common in academic writing. In other types of writing,

for example novels, the structure may be looser. Furthermore, paragraphs

may follow a different structure in other languages, for example, in Chi-

nese, where the main idea is expressed at the end of the paragraph.

Knapen, Chamba & Black

results suggest that xxxx. Another way to end is with a transi-

tion sentence, for example, the next Section describes xxxx.

Paragraphs should be neither too long nor too short. A para-

graph must contain just enough information to explain your

ideas to the reader, but avoid unnecessary detail. Nowadays,

paragraphs in academic writing tend to contain three to seven

sentences, though the length is somewhat journal-dependent.

In any case, avoid tremendously long and discouraging-looking

paragraphs that go half a page or more. Split the long ones up

into two smaller ideas, each with its own topic sentence.

Inexperienced writers may have problems writing well-

structured paragraphs. For example, they may find themselves

writing wandering paragraphs without any clear point. The

reader tries to follow, but starts to wonder ’where is this para-

graph going? What is the point the author is trying to make?’

Often the problem is the lack of a topic sentence. Example:

what is the point of the following paragraph?

In 2018 Brown measured x. Similarly Jones published y. Re-

cently Smith reported z.

Perhaps the writer intended to show that there has been a

lot of research on galaxy Q. In this case, a good topic sentence

could clarify the significance of these facts.

Recent research has focussed on the galaxy Q. In 2018

Brown measured x. Similarly Jones published y. Recently Smith

reported z.

Another common problem for beginning writers is trying to

cram too much into one paragraph. What is wrong with the

following paragraph?

We used several approaches to measure x. First we did a.

Then we did b and c. After measuring x, we also measured y.

This paragraph begins by describing the measurement of x,

but then gets off track by unexpectedly mentioning the mea-

surement of y. There are two possible ways to fix this problem.

Either change the topic sentence to include the measurement

of y (we used several approaches to measure x and y) or put

the measurement of y into a paragraph of its own.

6.2 Sentence Linkage

Beginning writers, particularly non-anglophones, often write

bumpy text that does not seem to flow. This problem can be

fixed by linking sentences to each other. In English the begin-

ning of a sentence always provides context and linkage, gener-

ally by repeating a word or concept that has already been men-

tioned, while the end of the sentence presents the new infor-

mation.

Here are several examples showing good linkage.

Galaxy W was recently discovered by Brown. This galaxy...

Renaming the noun galaxy links the sentences and leads prob-

ably to a description of the galaxy.

Galaxy B has been well characterized. In 2018 Brown re-

ported..., while a year later Jones published... In this case, ’well

characterized’ suggests research, which is listed in the following

sentences, so this structure leads to a good flow. The use of the

dates provides a bit of extra context, showing that this is recent

research.

There are currently three missions studying the comet.

First... Second... Third... Here, the specific mention of ’three mis-

sions’ (or perhaps ’several missions’) leads the reader to expect

the list that follows.

Another technique to improve linkage and flow is the use

of ’sign-post’ words that tell the reader the relationship of the

ideas. To list examples, you can use phrases like ’for example,’ ’for

instance,’ and ’such as.’ To show chronological order, use dates

19 In some languages, such as Persian, the structure is just the opposite: the

new information comes at the beginning of the sentence, while the old,

familiar, linking information comes at the end.

like ’in 2012’ or words like ’first,’ ’second,’ ’next,’ and ’finally.’ To

show cause and effect, use words or phrases like ’consequently’

or ’as a result.’ To suggest similarity, use words like ’similarly’ or

’likewise.’ To show contrast, use phrases like ’in contrast’ or ’on

the other hand.’

6.3 Avoiding Plagiarism

Many journals automatically scan uploaded manuscripts for pla-

giarism, using a service such as Crossref Similarity Check, pow-

ered by iThenticate.

Thus it has become very important to

avoid the appearance of plagiarism.

To avoid plagiarism, make sure to cite the sources of ideas

and to write text in your own words. If you are quoting a defini-

tion or standard description, put the quoted text between quo-

tation marks and provide the source.

Plagiarism may arise for several reasons. For example, you

cannot think of a better way to say it. To solve this problem, im-

prove your vocabulary and check sources like the Manchester

Academic Phrasebank

for ideas to expand your own vocab-

ulary of words and phrases. Or perhaps you copy a text, think-

ing ’I will change it later.’ But then you forget to change it, and

end up plagiarizing. To avoid this problem, do not take notes by

copying and pasting—always take notes in your own words. For

a full discussion of these and other tips on avoiding plagiarism,

see Roig (2015).

6.4 Tips for Nice Sentences

Make sentences just the right length. Sentences in academic

writing range on average between 18 and 32 words, with some

longer or shorter. Shorter sentences can provide a nice antidote

if the previous sentence was rather long. But sentences can

get too long and too complicated by the stringing together of

clauses, especially those that begin with ’which’ or ’that.’ Aim to

make these longer complex sentences represent no more than

one out of three or four in your paper.

Stick to a subject-verb-object structure. This structure

puts the verb right after the subject, where it belongs. So not

’characteristics such as a, b, c, d, e, f, and g were measured,’ but

much better ’we measured a, b, c, d, e, f, and g.’

Prefer active voice. Active voice leads to more lively writ-

ing, as demonstrated by the example in the previous paragraph.

Using active voice does not mean beginning every sentence

with ’we.’ Inanimate objects can also be the subject: this paper

presents...; the next section explains...; the results show...; this

model provides....

Use verb tenses correctly. The main verb tenses used in

academic writing are Present, Present Perfect, and Past.

Present tense for

1. facts and definitions

Ex: These giant low surface brightness galaxies form an inter-

esting class of objects.

2. referring to the paper or figures or tables in the paper

Ex: Fig. 1 shows.../ X is shown in Fig. 1/this paper presents...

Past tense for things you did in the past, or that somebody

else did in the past.

Ex: For each bin, we calculated the surface brightness.

Ex: The European Space Agency launched the Gaia satellite at

the end of 2013.

20 https://www.ithenticate.com/

21 https://www.phrasebank.manchester.ac.uk/

22 https://bsc.ua.edu/wp-content/uploads/2017/07/plagiarism-1.pdf

Astronomy Education Journal, 2021, Vol. 00, No. 0

Present perfect

1. to announce work done in the ’recent’ past with emphasis

on the current relevance.

Ex: We have explored the nature of the disc truncations in two

edge-on nearby Milky Way-like galaxies.

Ex: Algorithms have been proposed along this line.

2. for a process that began in the past and continues up to

now.

Ex: Over the last twenty years, there has been intensive re-

search into...

Keep subject and verb close together.

Not: A number of galaxies, some with spirals arms and oth-

ers with both spiral arms and a prominent bar, were observed.

But: We observed a number of galaxies, some ... etc.

Use appropriate verbs. People often mix the action we take,

as observers, or researchers, with what an object like a star or a

galaxy does.

An example: Galaxies concentrate a lot of dust in their cen-

tral regions. (Not necessarily, we see that the dust is concen-

trated there but did the galaxy do it? Write A lot of dust is con-

centrated in the central regions of galaxies.).

6.5 Place Modifiers Carefully

A modifier is a word or phrase which gives additional informa-

tion about another word or phrase.

Look at this example: orbiting at x km above the earth, we

could see the satellite. Are you really orbiting above the earth,

or is it the satellite? Verbal phrases, like orbiting at x km above

the earth should be placed directly before or directly after the

word they modify. So you can correctly write orbiting at x km

above the earth, the satellite could be seen with the naked eye

or we could see the satellite orbiting the earth at x km above

the earth.

What about last weekend when I was camping, I looked out

of my tent and could see the satellite in my pyjamas? What is

that satellite doing in your pyjamas? Prepositional phrases like

in my pyjamas usually work best right after the noun they mod-

ify. In some cases, the sentences really need a bit of rewrite. We

could put the part about the pyjamas into a separate sentence

or drop it, and tell about the satellite in the Western sky.

6.6 Correct Punctuation with Relative Clauses

First we need to define a few grammatical terms. A clause is a

group of words that contains a subject and a verb. So a clause

might be a whole sentence that can stand alone (an indepen-

dent clause). Or a clause might not be able to stand alone (a

dependent clause). Here we are concerned with a particular

class of dependent clauses, those that begin with which, who,

or that. This type of clause is known as a relative clause, since

the pronoun (which, who, or that) relates back to a previously

mentioned noun. Here is an example of a sentence containing

a relative clause: Prof. Smith, who discovered the galaxy, won

the Nobel prize. In this case, who refers to Prof. Smith.

The words which and who can be used in two ways: to give

defining information or extra, nondefining information.

Defining information is used to specify which person or

thing you are talking about.

Example: The professor who has a red shirt discovered a

new galaxy. In this case, there are several professors in the room,

and your friend is pointing out which one you should look at.

Thus the clause ’who has a red shirt’ defines which professor

your friend is talking about. Note that there are no commas

around the defining clause.

When talking about people, we usually use the pronoun

who, but for things, it is possible to use that or which to intro-

duce defining information.

Example: The galaxy which was discovered last week is

amazing. Note that here the clause ’which was discovered last

week’ defines which galaxy we are talking about, so there are

no commas. In this case, we could also use that instead of

which: the galaxy that was discovered last week is amazing.

Some writers prefer to use that for defining information and

save which for nondefining information (see below), but in fact

both these words are in common use for the defining clauses.

Nondefining information gives extra information about the

person or thing, but it is already clear which person or thing you

are talking about.

Example: Prof. Smith, who discovered the new galaxy, will

give the next lecture. In this case, we know exactly which pro-

fessor your friend is talking about: Prof. Smith. The clause ’who

discovered the new galaxy’ gives nondefining information, so in

fact this clause could be put into a separate sentence like this:

Prof. Smith will give the next lecture. She discovered the new

galaxy. Note that in this case, the commas around the defining

clause indicate that this is extra, nondefining information that

you could put some place else.

Note that the pronoun that is never used to give nondefining

information.

Who cares? Why does it matter whether I use commas or

not? Well, sometimes, putting in commas or leaving them out

changes the meaning of the sentence.

Example without commas (defining relative clause): The

model which I developed fits the data. In this case there are

many models under discussion, but the particular one that I de-

veloped fits the data.

Example with commas (nondefining relative clause): The

model, which I developed, explains the data. In this case, there

is only one model under discussion, it explains the data, and by

the way, I developed it. The information about who developed

the model could be put in a separate sentence: I developed a

model. The model explains the data.

In summary, if you need the information in the relative

clause to specify who or what you are talking about, then do

not use commas around the clause. If the information could

just as well be put into another sentence, then do use commas

around the clause.

6.7 Avoid Ambiguity with This

A common mistake is referring to something with ’this’, without

defining what it refers to. Such as here:

In many galaxies, secular evolution leads to the formation

of pseudo-bulges and also to other changes in their morphol-

ogy. This can be observed in both optical and radio imaging.

What can be observed? The secular evolution? The formation

of pseudo-bulges? Or the changes? To solve this problem, you

write this evolution can be observed.

6.8 Tricky Plurals

While most plurals in English are formed by adding ’s’ or ’es,’ sci-

ence uses some irregular plurals. ’Data’ is usually used as a plu-

ral, with the singular form being ’datum’ or ’a piece or item of

data.’ In singular/plural pairs, here are a few tricky plurals: anal-

ysis/analyses, spectrum/spectra, phenomenon/phenomena, cri-

terion/ criteria, matrix/matrices.

Knapen, Chamba & Black

6.9 Use of the Articles a/an/the

Articles (the dog, a galaxy) can be extremely tricky for many non-

native speakers because many or even most people in the world

do not use articles at all in their first language, or do not use

them like in English!

It is thus very common in their drafts

to see ’the’ and other articles where an English native speaker

would not place one, or to leave out an article where an anglo-

phone would place one.

You should also note that for native English speakers (or for

speakers of languages which treat articles in the same way as

English, such as Dutch or German and to a lesser extent French

and Spanish) the use of articles is often completely intuitive and

crystal-clear, and they may not understand how others can pos-

sibly have a problem with articles.

Here are the basic rules.

1. Does the reader know which one or ones you are talking

about? Then use ’the.’ The reader might know which one you

are talking about for the following reasons:

a. Known because you just introduced it.

There was an association between a and c . The association

remained robust after...

b. Known because you mention something related.

...galaxy x. The structure of the galaxy is... [every galaxy has

a structure]

c. Known because you define it in the sentence.

The causes of this rotation are...

d. Known because you name it.

We used data from the SIMBAD database. [You define the

database by giving the name, SIMBAD]

e. There is only one. The Milky Way. The Sun. However, do not

use ’the’ for the names of people. I sent the data to Peter

(not ’the Peter’). Do not add ’the’ to names of countries, but

be aware that ’the’ forms part of the name of some countries

(the United States, the Netherlands). The conference was in

Spain; next year it will be in the Netherlands.

2. If rule 1 does not apply and the noun is singular, use ’a’ or

’an.’ ’A’ is used before a consonant sound: a galaxy, a star, a DVD.

’An’ is used before a vowel sound: an element, an hour, an X-ray

emitter.

3. If rule 1 does not apply and the noun is plural or non-

countable, do not use any article.

Generally speaking, ab-

stract terms used in a broad, general sense are noncountable

and are not introduced with ’the’.

Examples with abstract nouns used in a general sense:

You need more information about the university program. (’In-

formation’ is used in a general sense.)

Phrasal verbs can be used in speech, but not in academic writ-

ing. (Both ’speech’ and ’academic writing’ are used in a general

sense.)

But when using these abstract terms in a restricted and spe-

cific sense, rule 1 applies, and ’the’ is used.

Examples with abstract nouns used in a restricted, specific

sense:

The information in that folder is not correct. (Specific informa-

tion)

The speech you hear on the street in New York is different from

the speech you hear in London. (Specific examples of speech)

23 See https://wals.info/feature/37A$#$2/19.6/35.5

24 Some languages do not differentiate between singular and plural nouns,

which leads to confusion with articles and matching up the verbs. For ex-

ample, in Indonesian, the structure is something like ’one book is brown;

two book is brown.’ If this situation is the case in your mother language,

be careful to make nouns singular and plural, and to match the verb to

the noun in English, so you have ’one book is brown; two books are blue.’

The writing in this paper is excellent. (Specific example of writ-

ing)

4. Some confusion may arise because some nouns can be

either countable or noncountable, depending on their usage.

To make matters worse, some nouns are countable in English

but not in other languages, and vice versa.

Examples of nouns used as countable:

We gave the students some exercises to help them practice the

use of articles. (countable, plural ’exercises’)

I was so busy in the lab yesterday! I did 72 analyses. (’analyses’

refers to analysed samples)

Examples with the same nouns used as noncountable:

You should not sit in front of the computer all day; you should

get some exercise. (’Exercise’ in general—maybe walking or cy-

cling. This is quite a different meaning than the written exer-

cises to practice the use of articles in the example above)

He entered the data into the computer for analysis. (In this case,

’analysis’ is used as a general abstract noun, like ’information’ in

the example above.)

For those whose native language does not use articles, prac-

tice the rules (you can find exercises on the internet), or anal-

yse some of the sentences in this paper. Can you identify why

an article is used or not? You will not perfect your use of ar-

ticles overnight, but with some regular attention to the issue,

you can improve a lot within a year or two. For those who are

anglophones, remember that articles are very difficult for your

nonanglophone colleagues. Be helpful, not critical. After all, is

your Indonesian/Russian/Persian perfect?

6.10 Adverbs

An adverb describes a verb, an adjective, or another adverb. It

tells us how, where, when, how much, how often, etc. Adverbs

of time (such as never, often, sometimes, also) usually do not

cause trouble, but the adverbs that end in -ly can be confusing.

They are formed:

• For most adjectives, add -ly: wonderful—wonderfully

• If an adjective ends in y, change y to i and add -ly: easy—

easily

• Ending in -able or -idle, change -e to -y: horrible—horribly

• Ending in c, add -ally: automatic—automatically

• Some adverbs are irregular and do not end in -ly: good—well

• And some do not change at all: fast—fast.

In fact, academic writing does not use a lot of adverbs to

modify adjectives or adverbs, except in the special case of past

participles used as adjectives. Examples are previously reported

data, a recently launched satellite, a carefully written report.

6.11 Amount vs Number

Use ’number’ for countable objects, and ’amount’ for measured

quantities.

Correct: The number of stars of a given mass...

Correct: The total amount of fuel needed to launch the satel-

lite... (or else the number of litres of fuel, since litres are count-

able).

Correct: The amount of time needed for the project... (or else

the number of months needed for the project, since months are

countable).

6.12 UK vs US Spelling

There are some differences in spelling between American and

British English. Examples are the American -or words which

Astronomy Education Journal, 2021, Vol. 00, No. 0

are written with -our in British English: color/colour, neigh-

bor/neighbour. American English ends some words with -er,

while British English uses -re: center/centre, meter/metre. Amer-

ican English has words that must end in -ize, while British

English also writes them with -ise: analyze/analyse, catego-

rize/categorise. Use the style and spelling appropriate to your

journal, and use the relevant spell checker to avoid mistakes.

Perhaps most importantly: be consistent throughout your pa-

per.

6.13 Literature

’Literature’ is poetry, novels, and plays; ’the literature’ is the pub-

lished body of work in your field.

6.14 Avoid Phrasal Verbs in Formal English

English uses many phrasal verbs, such as ’break down’ or ’talk

about,’ but these are informal. They can be used in speech but

not in formal writing. In almost all cases, there is a single, more

formal word that can replace the phrasal verb, for example, ’de-

stroy’ or ’decompose’ are more formal than ’break down,’ and

’discuss’ is more formal than ’talk about.’ The more formal ver-

sions are derived from a Latin root and often resemble words in

French or Spanish. Other examples are using the formal ’inves-

tigate’ instead of ’look into’ or the formal ’continue’ rather than

’go on.’

6.15 Infinitives and Gerunds as Nouns

Confusingly, English uses both infinitives and gerunds as nouns.

The infinitive is the ’to’ form, like ’to eat,’ and the gerund is the

noun form that ends in ’ing,’ like ’eating.’ In some cases, either

the infinitive or the gerund can be used: we began to investi-

gate the star or we began investigating the star. But depend-

ing on the main verb, it may be necessary to use the infinitive or

the gerund. We wanted to investigate the star because ’want’

requires the infinitive. We considered writing a paper because

’consider’ requires the gerund. Some verbs that are commonly

used in academic writing can be used in several different ways.

For example, the supervisor advised taking more observations

because ’advise’ requires the gerund. It is also correct to use the

structure the supervisor advised me to take more observations;

the infinitive is required when the person receiving the advice

is mentioned. In case of doubt about the correct usage, check

a dictionary such as The Longman Dictionary of Contemporary

English.

7 Concluding Remarks

This paper is a self-help guide to writing papers in astronomy

for students and beginning writers. Often, the expectation is

that students will learn how to write papers from their men-

tors or supervisors but not all mentors are the best of writers or

are trained, or even willing, to teach students how to write! We

hope our guide provides students with a clear framework to be-

gin writing their first paper. It is also aimed to encourage them

to first think before writing and, most importantly, to recognise

that writing is a process that can be learned and constantly im-

proved. For instance, by learning how to critically approach pa-

pers in the literature, you may then identify and learn how to

present the key message and findings of your own paper in a

25 https://www.ldoceonline.com/

self-critical, compelling and efficient manner.

Without a doubt, if you continue to practice and pay at-

tention to good planning and writing, it will become easier to

produce well-written papers. We also remind graduate pro-

gramme coordinators that writing in astronomy is an essential

skill for the future success of young researchers. We believe that

the writing experience of students would be greatly enhanced

if programmes included courses in academic writing as part of

their early scientific education or graduate research training.

This paper also summarises the writing process, from plan-

ning the paper and choosing a journal, through the organiza-

tion of the paper, to the mechanics of writing and polishing text,

with some tips given along the way to avoid plagiarism. We con-

centrate on scientific papers to be submitted to refereed pro-

fessional journals in astronomy. Based on our experience, we

believe that every researcher can learn to write clearly, compe-

tently and even gracefully. We provide these guidelines based

on our experience as writers and teachers, but take these guide-

lines as just that—only guidelines which will help you find your

own way to becoming a good writer. Your reward will be when

a colleague compliments you on your beautifully written paper!

8 Declarations

8.1 Ethical Approval (optional)

Not applicable.

8.2 Consent for Publication

Not applicable.

8.3 Competing Interests

The authors declare that they have no competing interests.

8.4 Funding

We acknowledge support from the European Union’s Hori-

zon 2020 research and innovation programme under Marie

Skłodowska-Curie grant agreement No 721463 to the SUN-

DIAL ITN network. JHK acknowledges financial support from

the State Research Agency (AEI-MCINN) of the Spanish Min-

istry of Science and Innovation under the grant ’The structure

and evolution of galaxies and their central regions’ with ref-

erence PID2019-105602GB-I00/10.13039/501100011033,

and from IAC project P/300724, financed by the Ministry of

Science and Innovation, through the State Budget and by the

Canary Islands Department of Economy, Knowledge and Em-

ployment, through the Regional Budget of the Autonomous

Community. NC acknowledges support from the research

project grant ‘Understanding the Dynamic Universe’ funded

by the Knut and Alice Wallenberg Foundation under Dnr KAW

2018.0067

8.5 Author’s Contributions

All authors developed the manuscript together. Individual au-

thors drafted sections and gave critical comments on the other

sections.

Knapen, Chamba & Black

9 Acknowledgements

We thank Sébastien Comerón, Simón Díaz-García, Erik & Laura

Knapen Almeida, Cristina Martínez-Lombilla, Rainer Schödel

and Aaron Watkins for comments on an earlier version of these

notes. NC also thanks T. Emil Rivera-Thorsen and Matteo Pom-

permaier for interesting discussions. Part of this paper is based

on a scientific writing course delivered by JHK to mostly MSc

and PhD students in Ethiopia and Rwanda. He wishes to thank

Professors Mirjana Pović and Pheneas Nkundabakura for organ-

ising those courses, and the students for participating.

10 Authors’ Information

JHK is a research professor of astrophysics with three decades of

experience of (co-)writing over 200 refereed research papers in

astronomy. He has edited a number of books and given courses

on academic writing. NC is a young author and postdoctoral

fellow in astronomy. Recognising that most of her Spanish-

speaking colleagues had a hard time writing papers, she or-

ganised the first scientific writing school at the Instituto de As-

trofísica de Canarias, Tenerife for PhD students in 2019. The

week-long course was given by DB, whom she and JHK met dur-

ing a SUNDIAL-ITN workshop, and inspired the making of this

guide. DB taught classes on publishing in English at the Uni-

versity of Groningen, the Netherlands, for 16 years. She is now

retired.

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