<p><a href="https://www.minorplanetcenter.net/iau/info/DesDoc.html" rel="nofollow noreferrer">Provisional designations</a> such as 2020 CD<sub>3</sub> are as you inferred: the number and first letter indicate the year and half-month of discovery, and the remainder is sequential within that half-month.
Well-observed objects with well-determined orbits get a permanent number designation and become eligible for a name, e.g. <a href="https://www.minorplanetcenter.net/db_search/show_object?object_id=Bennu" rel="nofollow noreferrer">(101995) Bennu</a> was previously known as 1999 RQ36.</p>
<p>Temporary designations of unknown objects are left up to the reporting observer, within certain <a href="https://minorplanetcenter.net/iau/info/Astrometry.html#id" rel="nofollow noreferrer">guidelines</a>: use 6 (preferred) or 7 characters beginning with a letter, avoid prefixes like J99 and K18 which resemble <a href="https://www.minorplanetcenter.net/iau/info/PackedDes.html" rel="nofollow noreferrer">packed</a> provisional designations, and try to make it unique.
Objects listed on the <a href="https://www.minorplanetcenter.net/iau/NEO_dev/ToConfirm.html" rel="nofollow noreferrer">NEO confirmation page</a> use such identifiers until there are enough observations for an orbit and a provisional designation.</p>
<p>If an object is known by a temporary designation long after discovery, either there weren't enough observations to determine a useful heliocentric orbit, or it was identified as space junk.
Occasionally a provisional designation is retracted, as when 2015 HP<sub>116</sub> was identified as the Gaia spacecraft.</p>

CC BY-SA 4.0
2020-11-23T21:57:09.887Z
2020-11-23T21:57:09.887Z
Mike G
<p>Is there a naming convention for temporary moons? Or do they follow the naming conventions of other small bodies?</p>
<p>In the case of 2006 RH<span class="math-container">$_{120}$</span>, 2015 HP<span class="math-container">$_{116}$</span>, 2020 CD<span class="math-container">$_3$</span> and 2020 SO, the first number is the year. I assume the following letter+number combination somehow indicates the time of year of discovery and/or the number of similar bodies discovered prior?</p>
<p>How were YX205B9, WT1190F, S509356 and XC83E0D named?</p>

<natural-satellites><naming>
What is the naming convention for temporary moons?
usernumber
# What is the naming convention for temporary moons?

(Asked by: username_0 on 2020-11-23)

Is there a naming convention for temporary moons? Or do they follow the naming conventions of other small bodies?

In the case of 2006 RH$\_{120}$, 2015 HP$\_{116}$, 2020 CD$\_3$ and 2020 SO, the first number is the year. I assume the following letter+number combination somehow indicates the time of year of discovery and/or the number of similar bodies discovered prior?

How were YX205B9, WT1190F, S509356 and XC83E0D named?

**Tags:** natural-satellites, naming


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## 1 answers

### Answer by username_1 on 2020-11-23. Score: 2

[Provisional designations](https://www.minorplanetcenter.net/iau/info/DesDoc.html) such as 2020 CD3 are as you inferred: the number and first letter indicate the year and half-month of discovery, and the remainder is sequential within that half-month.
Well-observed objects with well-determined orbits get a permanent number designation and become eligible for a name, e.g. [(101995) Bennu](https://www.minorplanetcenter.net/db_search/show_object?object_id=Bennu) was previously known as 1999 RQ36.

Temporary designations of unknown objects are left up to the reporting observer, within certain [guidelines](https://minorplanetcenter.net/iau/info/Astrometry.html#id): use 6 (preferred) or 7 characters beginning with a letter, avoid prefixes like J99 and K18 which resemble [packed](https://www.minorplanetcenter.net/iau/info/PackedDes.html) provisional designations, and try to make it unique.
Objects listed on the [NEO confirmation page](https://www.minorplanetcenter.net/iau/NEO_dev/ToConfirm.html) use such identifiers until there are enough observations for an orbit and a provisional designation.

If an object is known by a temporary designation long after discovery, either there weren't enough observations to determine a useful heliocentric orbit, or it was identified as space junk.
Occasionally a provisional designation is retracted, as when 2015 HP116 was identified as the Gaia spacecraft.


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