(103) Hera

103 Hera
Discovery
Discovered byJames Craig Watson[1]
Discovery date7 September 1868[1]
Designations
(103) Hera
Pronunciation/ˈhɪərə/[2]
Named after
Hera
1927 CV, 1950 CM
Main belt
Orbital characteristics[3]
Epoch 31 July 2016 (JD 2457600.5)[1]
Uncertainty parameter 0
Observation arc144.99 yr (52958 d)
Aphelion2.92042 AU (436.889 Gm)[1]
Perihelion2.48175 AU (371.265 Gm)[1]
2.70109 AU (404.077 Gm)[1]
Eccentricity0.0812034[1]
4.44 yr (1621.5 d)[1]
18.09 km/s
133.341°
0° 13m 19.279s / day
Inclination5.41957°
136.186°
188.361°
Earth MOID1.46898 AU (219.756 Gm)
Jupiter MOID2.32392 AU (347.653 Gm)
TJupiter3.356
Physical characteristics
Dimensions91.20±5.6 km
Mass7.9×1017 kg
Equatorial surface gravity
0.0255 m/s²
Equatorial escape velocity
0.0482 km/s
23.740 h (0.9892 d)[3]
0.9892 d[4]
0.1833±0.025
Temperature~170 K
S[5]
7.66

Hera (minor planet designation: 103 Hera) is a moderately large main-belt asteroid that was discovered by Canadian-American astronomer James Craig Watson on September 7, 1868,[6] and named after Hera, queen and fifth in power of the Olympian gods in Greek mythology. It is an S-type asteroid[5] 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.[4]

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.[7]

References[]

  1. ^ a b c d e f g h JPL Small-Body Database Browser
  2. ^ "Hera". Oxford English Dictionary (3rd ed.). Oxford University Press. September 2005. (Subscription or UK public library membership required.)
  3. ^ a b Yeomans, Donald K., "103 Hera", JPL Small-Body Database Browser, NASA Jet Propulsion Laboratory, retrieved 12 May 2016.
  4. ^ a b Pilcher, Frederick (January 2011), "Rotation Period Determination for 103 Hera", The Minor Planet Bulletin, 38 (1), p. 32, Bibcode:2011MPBu...38...32P.
  5. ^ a b 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, archived from the original (PDF) on 17 March 2014, retrieved 22 March 2013. See appendix A.
  6. ^ "Numbered Minor Planets 1–5000", Discovery Circumstances, IAU Minor Planet center, retrieved 7 April 2013.
  7. ^ Ryan, Erin Lee; et al. (April 2012), "The Kilometer-Sized Main Belt Asteroid Population as Revealed by Spitzer", arXiv:1204.1116 [astro-ph.EP].

External links[]