<p>The Lowell observatory gives temporary designations in the form &quot;A-number&quot; to objects that it studies. A1 would be a temporary designation that the Lowell observatory could give an object.  For example</p>
<blockquote>
<p>NGC 3603-A1 is likely the most massive binary star ever “weighed” through its orbital mass. [...]  We have also produced a light curve for <strong>A1</strong> using HST photometry, which provides a more accurate measurement of the systems inclination. Ultimately we hope to refine the masses of <strong>A1</strong> with new observations. <a href="https://ui.adsabs.harvard.edu/abs/2021AAS...23713305B/abstract" rel="nofollow noreferrer">Source</a></p>
</blockquote>
<p>There is an object (1)  it is (1) Ceres, the dwarf planet. And 1P is Halley's comet.</p>

CC BY-SA 4.0
2021-07-28T20:18:09.430Z
thx, know a resource to the naming conventions for celestial bodies?
user406126
CC BY-SA 4.0
2021-07-28T20:21:27.450Z
The minor planet centre for official names.  Wikipeida has a list of the temporary codes that various observatories conventionally give objects of study. https://en.wikipedia.org/wiki/Provisional_designation_in_astronomy  https://en.wikipedia.org/wiki/Astronomical_naming_conventions
James K
CC BY-SA 4.0
2021-07-30T11:27:38.240Z
Using MPC, I found two other entries which have "A1" in their name: C/2021 A1 (Leonard), A/2020 A1 (A/NEOWISE) [cc @user406126]
Nilay Ghosh
CC BY-SA 4.0
2021-07-28T14:04:56.487Z
2021-07-28T14:04:56.487Z
James K
<p>A quick check with the <a href="http://simbad.u-strasbg.fr/simbad/sim-fid" rel="nofollow noreferrer">Simbad database</a> shows nothing with the identifier &quot;A1&quot;.</p>
<p>A search on the <a href="http://ned.ipac.caltech.edu/byname" rel="nofollow noreferrer">NASA Extragalactic Database</a> turns up the galaxy cluster Abell 1 (or &quot;Abell 0001&quot;, as NED puts it), which <em>might</em> qualify, in that people will sometimes refer to Abell clusters using just &quot;A&quot; + the number (e.g., &quot;Abell 496&quot; gets a short name of &quot;A496&quot;). But that's an informal practice, so I'd conclude there aren't any celestal objects with a permanent/formal name of &quot;A1&quot;.</p>

CC BY-SA 4.0
2021-07-30T11:15:25.537Z
2021-07-30T11:15:25.537Z
Peter Erwin
<p>Is there a spatial entity (moon, planet, star, system, galaxy, cluster,..) that is identified with &quot;A1&quot; (or A{first_term})?</p>

CC BY-SA 4.0
2021-07-28T13:31:43.077Z
Not really… can you provide some context?
pela
<naming><stellar-classification>
Any stellar entity named A1?
user406126
# Any stellar entity named A1?

(Asked by: username_0 on 2021-07-28)

Is there a spatial entity (moon, planet, star, system, galaxy, cluster,..) that is identified with "A1" (or A{first\_term})?

**Tags:** naming, stellar-classification
> **Comments:**
> **username_1**: Not really… can you provide some context?  

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## 2 answers

### Answer by username_2 on 2021-07-28. Score: 3 | Accepted answer

The Lowell observatory gives temporary designations in the form "A-number" to objects that it studies. A1 would be a temporary designation that the Lowell observatory could give an object. For example

> NGC 3603-A1 is likely the most massive binary star ever “weighed” through its orbital mass. [...] We have also produced a light curve for **A1** using HST photometry, which provides a more accurate measurement of the systems inclination. Ultimately we hope to refine the masses of **A1** with new observations. [Source](https://ui.adsabs.harvard.edu/abs/2021AAS...23713305B/abstract)

There is an object (1) it is (1) Ceres, the dwarf planet. And 1P is Halley's comet.

> **Comments:**
> **username_0**: thx, know a resource to the naming conventions for celestial bodies?  
> **username_2**: The minor planet centre for official names.  Wikipeida has a list of the temporary codes that various observatories conventionally give objects of study. https://en.wikipedia.org/wiki/Provisional_designation_in_astronomy  https://en.wikipedia.org/wiki/Astronomical_naming_conventions  
> **username_3**: Using MPC, I found two other entries which have "A1" in their name: C/2021 A1 (Leonard), A/2020 A1 (A/NEOWISE) [cc @user406126]  

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### Answer by username_4 on 2021-07-30. Score: 2

A quick check with the [Simbad database](http://simbad.u-strasbg.fr/simbad/sim-fid) shows nothing with the identifier "A1".

A search on the [NASA Extragalactic Database](http://ned.ipac.caltech.edu/byname) turns up the galaxy cluster Abell 1 (or "Abell 0001", as NED puts it), which *might* qualify, in that people will sometimes refer to Abell clusters using just "A" + the number (e.g., "Abell 496" gets a short name of "A496"). But that's an informal practice, so I'd conclude there aren't any celestal objects with a permanent/formal name of "A1".


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