Gefion family


The Gefion family is an asteroid family located the in intermediate asteroid belt between 2.74 and 2.82 AU at inclinations of 7.4° to 10.5°. The family of S-type asteroids is named after 1272 Gefion and consists of more than 2,500 known members. It had previously been known as the Ceres family. It is still known as Minerva family, named after then thought parent body 93 Minerva, until it was identified to be an interloper into its own family.

Properties

The members have proper orbital elements in the approximate ranges
At the present epoch, the range of osculating orbital elements of these core members is
The namesake is 1272 Gefion. The family is fairly large, e.g. the Zappala 1995 analysis found about a hundred core members. A search of a recent proper element database found 766 objects lying within the region defined by the first table above.
2631 Zhejiang has a diameter of 34 km, and is the largest core member whose diameter has been reliably estimated, although 2911 Miahelena is brighter, and would have a rough diameter of about 47 km, given the same albedo of 0.025.

Core members

The core members identified by the Zappalà HCM method survey are shown in the table at right.

Alternative name and interlopers

Until recently, this family was known as the Ceres family or the Minerva family after 1 Ceres or 93 Minerva. However, spectroscopic analyses showed that these largest members were in fact interlopers in their own family, having a different spectral class from the bulk of the members. Other known interlopers are 255 Oppavia, 374 Burgundia, 2507 Bobone, and 2559 Svoboda. This left the fairly minor asteroid 1272 Gefion as the lowest-numbered member.

List of members

This is a list of the known family members, without the above-mentioned interlopers.
Namea e
1272 Gefion2.783850.15170
1433 Geramtina2.799480.16918
1751 Herget2.793190.17242
1839 Ragazza2.798980.16824
2053 Nuki2.802600.14050
2157 Ashbrook2.784400.11071
2373 Immo2.794330.17339
2386 Nikonov2.814560.15728
2493 Elmer2.787770.17198
2521 Heidi2.794750.08893
2595 Gudiachvili2.785950.14340
2631 Zhejiang2.797300.16070
2801 Huygens2.799690.17422
2875 Lagerkvist2.797920.09969
2905 Plaskett2.802330.09847
2911 Miahelena2.795200.09303
2977 Chivilikhin2.788840.16849
3724 Annenskij2.762930.16535
3788 Steyaert2.793070.10127
3860 Plovdiv2.805860.15548
3910 Liszt2.794420.13349
3964 Danilevskij2.758220.16608
4020 Dominique2.776260.15885
4096 Kushiro2.809890.15066
4182 Mount Locke2.798060.13498
4702 Berounka2.793870.09181
5159 Burbine2.789790.10861
5401 Minamioda2.794630.15238

Namea e
10665 Ortigão2.798510.15765
12275 Marcelgoffin2.763150.15291
12279 Laon2.769900.09282
2.812100.10526
2.768100.16222
2.765750.17269
2.815250.15026
2.785140.15738
2.787850.17691
2.789870.17546
19994 Tresini2.774680.17725
2.758280.11401
2.761960.10315
2.813910.17207
2.804450.18117
1989 WH2.761960.14457
1979 XL2.786490.11048
2.798520.15112
2.763770.14769
2.772250.10578
2.757020.12711
2.764690.16515
2.743680.08177
2.776350.10965
2.761540.11756
2.793370.16135
2.784910.17877
2.80350.1627