103 Hera
Discovery | |
---|---|
Discovered by | James Craig Watson[1] |
Discovery date | 7 September 1868[1] |
Designations | |
Named after | Hera |
1927 CV, 1950 CM | |
Main belt | |
Orbital characteristics[2] | |
Epoch 31 July 2016 (JD 2457600.5)[1] | |
Uncertainty parameter 0 | |
Observation arc | 144.99 yr (52958 d) |
Aphelion | 2.92042 AU (436.889 Gm)[1] |
Perihelion | 2.48175 AU (371.265 Gm)[1] |
2.70109 AU (404.077 Gm)[1] | |
Eccentricity | 0.0812034[1] |
4.44 yr (1621.5 d)[1] | |
Average orbital speed | 18.09 km/s |
133.341° | |
0° 13m 19.279s / day | |
Inclination | 5.41957° |
136.186° | |
188.361° | |
Earth MOID | 1.46898 AU (219.756 Gm) |
Jupiter MOID | 2.32392 AU (347.653 Gm) |
Jupiter Tisserand parameter | 3.356 |
Physical characteristics | |
Dimensions | ±5.6 km 91.20 |
Mass | 7.9×1017 kg |
Equatorial surface gravity | 0.0255 m/s² |
Equatorial escape velocity | 0.0482 km/s |
23.740 h (0.9892 d)[2] 0.9892 d[3] | |
±0.025 0.1833 | |
Temperature | ~170 K |
S[4] | |
7.66 | |
|
103 Hera is a moderately large main-belt asteroid that was discovered by Canadian-American astronomer James Craig Watson on September 7, 1868,[5] and named after Hera, queen and fifth in power of the Olympian gods in Greek mythology. It is an S-type asteroid[4] with a silicate surface composition.
Photometric observations made in 2010 at the Organ Mesa Observatory at Las Cruces, New Mexico, and the Hunters Hill Observatory at Ngunnawal, Australian Capital Territory, give a synodic rotation period of 23.740 ± 0.001 hours. The bimodal light curve shows a maximum brightness variation of 0.45 ± 0.03 in magnitude.[3]
Measurements made with the IRAS observatory give a diameter of 91.58 ± 4.14 km and a geometric albedo of 0.19 ± 0.02. By comparison, the MIPS photometer on the Spitzer Space Telescope gives a diameter of 88.30 ± 8.51 km and a geometric albedo of 0.20 ± 0.04. When the asteroid was observed occulting a star, the results showed a diameter of 89.1 ± 1.1 km.[6]
References
- 1 2 3 4 5 6 7 8 JPL Small-Body Database Browser
- 1 2 Yeomans, Donald K., "103 Hera", JPL Small-Body Database Browser, NASA Jet Propulsion Laboratory, retrieved 12 May 2016.
- 1 2 Pilcher, Frederick (January 2011), "Rotation Period Determination for 103 Hera", The Minor Planet Bulletin, 38 (1), p. 32, Bibcode:2011MPBu...38...32P.
- 1 2 DeMeo, Francesca E.; et al. (2011), "An extension of the Bus asteroid taxonomy into the near-infrared" (PDF), Icarus, 202 (1): 160–180, Bibcode:2009Icar..202..160D, doi:10.1016/j.icarus.2009.02.005, retrieved 2013-03-22. See appendix A.
- ↑ "Numbered Minor Planets 1–5000", Discovery Circumstances, IAU Minor Planet center, retrieved 2013-04-07.
- ↑ Ryan, Erin Lee; et al. (April 2012), "The Kilometer-Sized Main Belt Asteroid Population as Revealed by Spitzer", eprint arXiv, arXiv:1204.1116, Bibcode:2012arXiv1204.1116R.
External links
- 103 Hera at the JPL Small-Body Database