444 Gyptis
| Discovery | |
|---|---|
| Discovered by | J. Coggia |
| Discovery date | 31 March 1899 |
| Designations | |
| (444) Gyptis | |
| Pronunciation | /ˈdʒɪptɪs/ |
Named after | Gyptis |
| 1899 EL | |
| Main belt | |
| Adjectives | Gyptidian |
| Orbital characteristics[1] | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 116.54 yr (42568 d) |
| Aphelion | 3.25674 AU (487.201 Gm) |
| Perihelion | 2.28337 AU (341.587 Gm) |
| 2.77005 AU (414.394 Gm) | |
| Eccentricity | 0.17569 |
| 4.61 yr (1684.0 d) | |
| 11.8852° | |
| 0° 12m 49.615s / day | |
| Inclination | 10.2775° |
| 195.716° | |
| 154.984° | |
| Physical characteristics | |
| Dimensions | 179×150 km[2] |
| 159.331±0.490 km[1] 164.63±2.60 km[3] | |
| Mass | 1.25×1019 kg[4] (1.06±0.28)×1019 kg[3] |
Mean density | 5.53±1.46 g/cm3[4] 4.55±1.23 g/cm3[3] |
| 6.214 h (0.2589 d)[1] | |
| 0.051±0.008[1] | |
| C[1] | |
| 8.07[1] | |
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.[5]
In 2004, Kochetova estimated Gyptis to have a mass of 1.25×1019 kg with a high density of 5.53 g/cm3.[4] In 2012 Carry estimated the mass as (1.06±0.28)×1019 kg with a high density of 4.55±1.23 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.[6] 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
[edit]- ^ a b c d e f "JPL Small-Body Database Browser: 444 Gyptis (1899 EL)" (2024-09-25 last obs). Retrieved 19 December 2024.
- ^ a b "2007 European Asteroidal Occultation Results". euraster.net (a website for Asteroidal Occultation Observers in Europe). 14 October 2007. Retrieved 1 December 2008. (Chords)
- ^ a b c d Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science, vol. 73, pp. 98–118, arXiv:1203.4336, Bibcode:2012P&SS...73...98C, doi:10.1016/j.pss.2012.03.009. See Table 1.
- ^ a b c Jim Baer (2008). "Recent Asteroid Mass Determinations". Personal Website. Archived from the original on 2 July 2013. Retrieved 27 November 2008.
- ^ Fornasier, S.; et al. (February 1999), "Spectroscopic comparison of aqueous altered asteroids with CM2 carbonaceous chondrite meteorites", Astronomy and Astrophysics Supplement, 135: 65−73, Bibcode:1999A&AS..135...65F, doi:10.1051/aas:1999161.
- ^ Marchis, F.; et al. (November 2006), "Shape, size and multiplicity of main-belt asteroids. I. Keck Adaptive Optics survey", Icarus, 185 (1): 39–63, Bibcode:2006Icar..185...39M, doi:10.1016/j.icarus.2006.06.001, PMC 2600456, PMID 19081813.
External links
[edit]- 444 Gyptis at AstDyS-2, Asteroids—Dynamic Site
- 444 Gyptis at the JPL Small-Body Database
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