# 148 Gallia

**148 Gallia** is a stony main-belt asteroid about 80 to 98 km in diameter, discovered on 7 August 1875 at Paris by the French astronomer Prosper Henry and named after Gallia, the Latin name for France.<sup>[1](https://www.le-systeme-solaire.net/astero1.html)</sup> It is the namesake and largest reference body of the Gallia asteroid family, one of the few collisional families in the main belt with a distinctly high orbital inclination.<sup>[2](https://academic.oup.com/mnras/article/463/1/705/2589983)</sup>

| Key fact | Detail |
|---|---|
| Discovery | 7 August 1875, Paris, by Prosper Henry<sup>[1](https://www.le-systeme-solaire.net/astero1.html)</sup> |
| Diameter | Published estimates range from 80.87±1.04 km to 97.75±3.7 km<sup>[7](https://astro.kretlow.de/simda/show1/Gallia)</sup> |
| Observation record | 5,333 optical observations across 80 oppositions, 1879 to 2026<sup>[3](https://astorb.com/info/148.html)</sup> |

## Orbit and physical properties

**Slow rotation.** The independent determinations agree on a rotation period of about 20.66 hours, roughly three times slower than the few-hour spins common among asteroids of this size.

## The Gallia family

In hierarchical clustering studies of proper elements, the family is re-identified by starting from (148) Gallia as the first central body, with members linked out to a cut-off velocity of 280 m/s, a value at which no other independent cluster was found in the region.<sup>[4](https://academic.oup.com/mnras/article/408/1/580/1060582)</sup>

The [Gallia family](https://www.edgepedia.org/gallia-family) belongs to a small set of highly inclined families in the main belt, together with the Hansa and Barcelona families.<sup>[2](https://academic.oup.com/mnras/article/463/1/705/2589983)</sup> Studies of the ejection velocity fields of asteroid families found that the distribution of the out-of-plane velocity component for Gallia family members is more peaked than a Gaussian, a property used alongside numerical simulations to constrain the family's age and the strength of the Yarkovsky force, the small thermal radiation effect that slowly drifts family members in semi-major axis.<sup>[5](https://academic.oup.com/mnras/article/457/2/1332/968601)</sup><sup> • </sup><sup>[2](https://academic.oup.com/mnras/article/463/1/705/2589983)</sup>

## Observation history

The asteroid has been followed since 1879, when Paul and Prosper Henry observed it with the west equatorial of the Paris Observatory garden; their 1879 positional measurements were published in the Annales de l'Observatoire de Paris.<sup>[6](https://www.persee.fr/doc/aopo_2022-8635_1882_num_1879_1_1428)</sup> The modern observation record stands at 5,333 optical observations over 80 oppositions from 1879 to 2026, giving an orbit uncertainty parameter of 0.<sup>[3](https://astorb.com/info/148.html)</sup>

## References

1. [Liste des astéroïdes du n°1 au n°500, Le Système Solaire](https://www.le-systeme-solaire.net/astero1.html)
2. [On the highly inclined vW leptokurtic asteroid families, Monthly Notices of the Royal Astronomical Society](https://academic.oup.com/mnras/article/463/1/705/2589983)
3. [小行星(148) Gallia的基本参数, astorb.com](https://astorb.com/info/148.html)
4. [The stable archipelago in the region of the Pallas and Hansa dynamical families, Monthly Notices of the Royal Astronomical Society](https://academic.oup.com/mnras/article/408/1/580/1060582)
5. [Constraints on the original ejection velocity fields of asteroid families, Monthly Notices of the Royal Astronomical Society](https://academic.oup.com/mnras/article/457/2/1332/968601)
6. [Observations faites à l'Équatorial ouest du Jardin, Annales de l'Observatoire de Paris (Persée)](https://www.persee.fr/doc/aopo_2022-8635_1882_num_1879_1_1428)
7. [SiMDA»Main, astro.kretlow.de](https://astro.kretlow.de/simda/show1/Gallia)

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*Topic: Encyclopedia › Places and geography › Extraterrestrial places › Small bodies of the Solar System › Main-belt asteroids and numbered minor planets › Middle-belt asteroids › Asteroids named for places*

*Initially written Oct 21, 2026 · Edited: Oct 25, 2026*

*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*

License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license