Frequently Asked Questions

  1. The IAU
  2. Research and Observations
  3. Astronomy Education and Outreach
  4. The Moon
  5. Pluto
  6. Objects within the Solar System
  7. Stars, Galaxies, and Nebulae
  8. Astronomers and General Astronomy


Q: What is the IAU?

A: The International Astronomical Union (IAU) is an internationally recognised body with the mission to promote and safeguard the science of astronomy in all its aspects. Its international membership consists of astronomical societies representing national or regional interests and individual astronomers active in professional research, education and outreach of astronomy.

Key activities of the IAU include:

  • Organising scientific meetings around the globe;
  • Defining fundamental astronomical and physical constants and ambiguous astronomical nomenclature;
  • Facilitating informal discussion on the possibility of future large-scale international observing facilities;
  • Assigning naming designations to celestial bodies and their surface features;
  • Promoting astronomical research, education and outreach within the public sphere.

Read more on our ‘About’ web page:

Q: How can I become a member of the IAU?

A: You can find requirements and procedures on this webpage:

Q: Can I use the IAU logo on my materials?

A: The IAU's logo is protected and may not be used or reproduced without the prior and individual written consent of the IAU Press Office. Please review the full conditions on this webpage:

Q: Can I use IAU images and videos?

A: Yes, IAU images and videos are released under a Creative Commons license. You can use IAU images and videos so long you give proper credit to the IAU and partners listed in the description of each photo or video. The IAU logo is not licensed under Creative Commons. Please review the full conditions on this webpage:

Q: Can I translate an IAU webpage/newsletter/other text on the website?

A: Yes, the text on our website falls under the same Creative Commons license like our images and videos. Proper credit must be given to the IAU or indicated partners as the text source in the translation. Please review the full conditions on this webpage:

Additionally, please reach out to with your translation so we may share it to a wider audience.

Q: Is there an IAU archive of documents?

A: Yes, the IAU archives are housed at the Institut d’Astrophysique de Paris (IAP), host of the IAU Secretariat. Some older documents continue to be digitised by Cambridge University Press. All new documents in regard to scientific meetings are processed through Cambridge University Press. Further information about this arrangement can be found here:

Available digital documents can be found via the drop-down menu of the ‘Publications’ tab on the IAU website:

Physical copies of some IAU documents can be found at the IAU Secretariat in Paris, France. Please contact for more information on how to review these documents in person.

Q: Can we make a donation to the IAU to honour somebody?

A: Yes, thank you for considering a donation to the IAU. You can find more information here:

Q: How can I work at the IAU?

A: The IAU will post job openings in the ‘Announcements’ or ‘Press Releases’ when these opportunities become available. You can find these on the homepage of the IAU website:

If you are interested in becoming a member, please see this webpage:

Sometimes scientific bodies within the IAU will ask for volunteers who are unaffiliated with the IAU. Information regarding this will be posted on the body’s webpage (links can be found in the ‘Science’ tab in the menu above) and on the IAU Facebook and Twitter (links are in the sidebar on the IAU website home page).

The IAU offices will sometimes ask for volunteers. Please see their social media or website for potential opportunities:

Office of Astronomy for Development:
Office for Astronomy Outreach:
Office of Astronomy for Education:

You can also check the Volunteer Portal here:

Q: Why does the IAU use the terms “China-Nanjing” and “China-Taipei” for national membership?

A: The “China-Nanjing” and “China-Taipei” denominations used by the IAU refer to the seats of the respective astronomical societies. Astronomers (including amateur astronomers) in both geographical areas follow the official agreement on these denominations, which was signed by both parties and approved during the XVIII IAU General Assembly in 1982.

Q: What is the IAU stance and opinion on the TMT on the summit of Mauna Kea?

A: While we are aware of the situation regarding the construction of the Thirty Meter Telescope (TMT) and understand that it is a deeply complex and sensitive issue, our goal is to advance astronomical science and unite communities internationally. As such, the IAU does not offer opinions on individual telescope projects.

The IAU strives to make astronomy accessible for both astronomers and the public, and is committed to sharing astronomy with communities around the world. We believe that telescopes and observatories are both professional tools for astronomers and windows for all to the wonders of the Universe.

Q: What is the IAU doing about satellite constellations?

A: The IAU is involved in a few initiatives to protect our dark and quiet skies, and strongly recommends that all stakeholders in this new and unregulated frontier of space utilisation work collaboratively to their mutual advantage. The IAU hosts the Centre for the Protection of the Dark and Quiet Sky:

Further information on satellite constellations can be found here:

Q: Can the IAU participate in a petition?

A: In principle, the IAU does not participate in petitions.

Q: Why do some National Members display the Status of Suspended or Terminated?

A: A National Member is automatically suspended if its annual contributions have not been paid for five years. After five years of suspension, the IAU Executive Committee may recommend to the General Assembly to terminate the Membership. Read more details about the National Member status here.

Q: Can IAU members be expelled?

A: According to the IAU Code of Conduct (Appendix B, section d.), the IAU membership of individuals may be revoked for serious violations of the IAU Code of Conduct during IAU meetings or activities. The IAU Executive Committee would always consult with the Membership Committee and the respective National Member.


Research and Observations

Q: I have written a scientific paper. Can you please review it?

A: The IAU has only two peer-reviewed journals for research papers and articles. One journal concerns the public outreach of astronomy called the Communicating Astronomy with the Public Journal (CAPjournal). You can find full submission guidelines on the CAPjournal website: The other journal concerns astronomy in education called the Astronomy Education Journal (AEJ). You can find full submission guidelines on the AEJ website:

We otherwise cannot accept scientific papers. Instead, we recommend that you submit your paper to a scientific publisher such as the following:

Astronomy & Astrophysics:
IOP Science:
American Astronomical Society:

Please note that this list is not exhaustive.

Q: How can you calculate the position of the planets on a specific date?

A: NASA's JPL Horizons website has an online tool for calculating the position of planets:

For years earlier than 1000, include 'AD' or 'BC' in the ‘Time Span’ field.

Q: I took an astronomical image. Can you publish my photo?

A: The IAU does not publish submitted astronomical images. Some places where you may be able to submit a photo include:

Astronomy magazines, like Sky & Telescope:
Astronomy Picture of the Day:
The World at Night:

Please note that this list is not exhaustive.

Q: I observed an object in the sky. Can you please identify it?

A: Unfortunately, we are unable to investigate any individual’s observations at this time. We recommend that you contact your local amateur astronomy club and attend one of their observing sessions to find out more information. We also have a guide on how to report a discovery here:

Q: Should I report the astronomical transient (supernova, etc…) to the CBAT or the TNS?

A: The IAU Transient Name Server is the only official tool for reporting astronomical transients. The Central Bureau for Astronomical Telegrams(CBAT) in regards to transients ended on 1 January 2016.

Read more about reporting procedures in general here:

Q: I have found a meteorite. Can the IAU help me to verify it?

A: The IAU doesn’t offer any meteorite identification or verification services. Geological laboratories in your country and the following webpage may be able to help:


Astronomy Education and Outreach

Q: What are the global events that celebrate astronomy?

A: There are many global celebrations of astronomy and space. Some include:

Q: Where can I subscribe to the Communicating Astronomy with the Public Journal (CAPjournal)?

A: You can subscribe to the CAPjournal on their website here:

Digital copies of the previous editions can be found here:

Q: How can I pursue a career in astronomy research?

A: A good background in maths, physics, chemistry and computer science is required to be a modern astronomer — this means pursuing a scientific high school curriculum followed by earning a university degree in physics or maths or engineering and then earning a PhD in astronomy or astrophysics.

Read more at:

Q: I need help with my education. Can you help me?

A: We offer a number of programmes for recognition and skills development for early-career astronomers, such as the International School for Young Astronomers for master’s students and IAU PhD Prize for recent PhD graduates. We also grant a number of travel grants for each IAU meeting. You can find links here:

International School for Young Astronomers:
IAU PhD Prize:
IAU travel grants:

The IAU offices also manage or fund a number of educational and outreach programmes that change throughout the year. Please see their websites for more information about opportunities through these offices:

Office of Astronomy for Development:
Office for Astronomy Outreach:
Office of Astronomy for Education:

The IAU does not offer direct funding, like scholarships, for educational opportunities at this time.


The Moon

Q: Where can I find information on lunar craters?

A: You can find the information here:

Q: Is it correct to refer to a natural satellite around a planet other than the Earth as a moon?

A: Yes, a natural satellite of other planets can be referred to as a moon. However, the IAU formally recommends that only the Earth's natural satellite, the Moon, should start with a capital letter to indicate the specific name of the Earth’s moon. Read more in this IAU Theme:

Q: Why doesn't the Moon have a name?

A: The Moon does have a name: the Moon. Formally, the IAU has approved of using “the Moon” as the name of the Earth’s moon through its use in multiple English-language IAU resolutions and IAU Style Manual, which was approved by resolution in 1988. Read more in this IAU Theme:



Q: I heard that Pluto is now a planet. Is this true?

A: The IAU has not changed the definition of a planet in the Solar System since 2006.

Read more here:

Q: Why isn’t Pluto a planet?

A: Determining what is a planet has been a discussion for many centuries as more and more astronomical objects have been observed. Since the early 1900s, the IAU has been responsible for the naming and nomenclature of planetary bodies and their satellites, and in the early 2000s astronomers began observing Pluto-like objects beyond Pluto’s orbit. This instigated a reconsideration of what astronomers deemed a planet.

After a vigorous debate among astronomers, the first draft of the definition of a planet was presented during the XXV IAU General Assembly in Prague, the Czech Republic. At the end of the assembly, IAU members approved Resolution B5 and defined a planet of the Solar System as the following:

A celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

Pluto does not meet this criteria, and it is therefore not a planet. Pluto is instead a dwarf planet.

For more information, please read this webpage:


Objects within the Solar System

Q: Can I propose names for minor planets, like asteroids?

A: Names for minor planets are proposed by the discoverer of the specific object after the object is numbered. You may wish to contact some of the minor planet discoverers or discovery programmes, as they may have unnamed numbered asteroids.

Read more here:

Q: How are planetary feature names approved? Can I suggest a name for a planetary feature?

A: This page from the IAU Working Group for Planetary System Nomenclature (WGPSN) describes the process:

If you are a member of the scientific community and have a specific scientific need to name a planetary surface feature, you can request that the feature be named by filling out the name request form:

Read more about naming here:

Q: Where can I verify the name of a planetary feature and the origin of its name?

A: Approved names for planetary features are entered into the Gazetteer of Planetary Nomenclature and added to the following website:

Read more about naming here:

Q: If a surface feature is named after a person who later turns out to have a darker side to their character, can that feature be renamed after somebody else?

A: The IAU does not name any planetary surface features, satellites or rings to commemorate people. If a person's name is used, it was chosen because of scientific need, and to fit the theme that was defined for naming that type of landmark. The IAU avoids changing any planetary names because there are publications as well as old maps and globes with those names, and it causes confusion in the literature and research to change them. Therefore, we only recommend changing a name if absolutely and demonstratively required.

Read more about naming here:


Stars, Galaxies, and Nebulae

Q: Can I buy a star?

A: The IAU dissociates itself entirely from the commercial practice of "selling" fictitious star names or "real estate" on other planets and celestial bodies.

In line with this, the IAU doesn't offer a star-naming service. There is no official alternative to the commercial practice of "selling" fictitious star names or "real estate" on other planets or moons in the Solar System.

More information is available here:

If you are looking to honour someone with purchasing a star, please consider donating in their name to the IAU, a local planetarium, or local astronomical society, or by visiting a nearby planetarium or observatory.

Q: Where can I find the list of IAU star names?

A: You can find the list here:

Q: Where can I find information about every constellation?

A: Please see the IAU Theme ‘Constellations’ here:

Q: How many constellations are in the zodiac? Does Ophiuchus belong to the zodiac?

A: In astronomy, the constellations of the zodiac are defined by the apparent path of the Sun against the stars in our sky, and were originally devised by the ancient Babylonians. When creating the zodiac, the Bablyonians noticed that the Sun moved through 13 constellations, but decided to leave one of them out (Ophiuchus) to be more consistent with their 12 month lunar calendar. Their zodiac contained 12 evenly-spaced constellations in the night sky. (Note, however, that astronomical constellations are not evenly spaced across the sky: they have different shapes and sizes according to well-defined boundaries, meaning that the Sun spends different amounts of time in each constellation.) So, according to astronomy, Ophiuchus is one of the constellations of the zodiac, and has been for quite some time. For more information, see this blog post from NASA.

Q: Can the IAU rename this nebula/galaxy/other deep-sky object?

A: Deep-sky objects, for scientific research, are designated by one or more acronyms for a catalogue or collection followed by a unique sequence of alphanumeric characters. For example, NGC 6720 and IC 165. These name assignments are determined by the creators of the catalogue or collection following an ordering recommended by the IAU. Astronomical objects are most generally referred to by these designations in scientific literature and databases.

For more information on naming, please see:


Astronomers and General Astronomy

Q: I have a specific question about an astronomical topic. Can you help?

A: Unfortunately we are not able to answer emails about specific astronomical topics. However, there are several websites that can give you detailed information if you post a question.

Some of these websites include:

Q: Will the recommendation to rename the Hubble law to the Hubble-Lemaître law lead to other renamings?

A: The historical contributions of Lemaître to the Hubble-Lemaître law have been made clear and, as one of the most important astronomical discoveries, recognising these contributions are important in recognising the history of astronomy. While correcting historical naming with better accuracy is something to strive for, this does not mean that other historical reflections should be modified by IAU resolutions. You can read the full resolution here:


Q: I would like to know about the distribution of astronomers in my country and gender distribution of astronomers.

A: Please see our webpage on our membership statistics here: