103 Hera

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.

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

    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. 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. Yeomans, Donald K., "103 Hera", JPL Small-Body Database Browser, NASA Jet Propulsion Laboratory, retrieved 12 May 2016.
    4. Pilcher, Frederick (January 2011), "Rotation Period Determination for 103 Hera", The Minor Planet Bulletin, 38 (1), p. 32, Bibcode:2011MPBu...38...32P.
    5. 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].


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