Astronomy:444 Gyptis
| Discovery | |
|---|---|
| Discovered by | J. Coggia |
| Discovery date | 31 March 1899 |
| Designations | |
| (444) Gyptis | |
| Pronunciation | /ˈdʒɪptɪs/ |
| Named after | Gyptis |
| 1899 EL | |
| Minor planet category | Main belt |
| Adjectives | Gyptidian |
| Orbital characteristics[1] | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 116.54 yr (42568 d) |
| |{{{apsis}}}|helion}} | 3.25674 astronomical unit|AU (487.201 Gm) |
| |{{{apsis}}}|helion}} | 2.28337 AU (341.587 Gm) |
| 2.77005 AU (414.394 Gm) | |
| Eccentricity | 0.17569 |
| Orbital period | 4.61 yr (1684.0 d) |
| Mean anomaly | 11.8852° |
| Mean motion | 0° 12m 49.615s / day |
| Inclination | 10.2775° |
| Longitude of ascending node | 195.716° |
| 154.984° | |
| Physical characteristics | |
| Dimensions | 179×150 km[2] 163.08±10.0 km[1] |
| Mass | 1.25×1019 kg[3] |
| Mean density | 5.53±1.46 g/cm3[3] |
| Rotation period | 6.214 h (0.2589 d)[1] |
| Geometric albedo | 0.0490±0.007[1] |
| C[1] | |
| Absolute magnitude (H) | 7.83[1] |
Gyptis, minor planet designation: 444 Gyptis, is a main-belt asteroid that was discovered by J. Coggia on March 31, 1899, in Marseilles. It is classified as a C-type asteroid and is probably composed of carbonaceous material. The spectra of the asteroid displays evidence of aqueous alteration.[4]
In 2004, Kochetova estimated Gyptis to have a mass of 1.25×1019 kg with a high density of 5.53 g/cm3.[3] The adaptive optics instrument at the W. M. Keck Observatory showed an object with a diameter of 129 km, which is much smaller than the estimate of 160 km from the IRAS observatory measurements, indicating an irregular shape. The size ratio between the major and minor axes is estimated at 1.40.[5] Observations of an occultation on October 14, 2007, produced six chords indicating a cross-section ellipsoid of 179×150 km.[2]
Between 1990 and 2021, 444 Gyptis has been observed to occult 17 stars.
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 "JPL Small-Body Database Browser: 444 Gyptis (1899 EL)". https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=444.
- ↑ 2.0 2.1 "2007 European Asteroidal Occultation Results". euraster.net (a website for Asteroidal Occultation Observers in Europe). 2007-10-14. http://www.euraster.net/results/2007/index.html#1014-444. (Chords)
- ↑ 3.0 3.1 3.2 Jim Baer (2008). "Recent Asteroid Mass Determinations". Personal Website. http://home.earthlink.net/~jimbaer1/astmass.txt.
- ↑ Fornasier, S. et al. (February 1999), "Spectroscopic comparison of aqueous altered asteroids with CM2 carbonaceous chondrite meteorites", Astronomy and Astrophysics Supplement 135: 65−73, doi:10.1051/aas:1999161, Bibcode: 1999A&AS..135...65F.
- ↑ Marchis, F. et al. (November 2006), "Shape, size and multiplicity of main-belt asteroids. I. Keck Adaptive Optics survey", Icarus 185 (1): 39–63, doi:10.1016/j.icarus.2006.06.001, PMID 19081813, Bibcode: 2006Icar..185...39M.
External links
- 444 Gyptis at AstDyS-2, Asteroids—Dynamic Site
- 444 Gyptis at the JPL Small-Body Database
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