|Discovery site||Kitt Peak National Obs.|
|Discovery date||8 April 2008|
|(457175) 2008 GO98|
|2008 GO98 · 362P|
|main-belt · (outer)|
|Epoch 4 December 2015 (JD 2457360.5)|
|Uncertainty parameter 0|
|Observation arc||16.05 yr (5,862 d)|
|7.89 yr (2,883 d)|
|0° 7m 29.64s / day|
|Jupiter MOID||0.3592 AU|
|5.5–24.7 km (est.)|
14.64 h (calculated)
(457175) 2008 GO98, provisional designation 2008 GO98 with cometary number 362P, is a Hildian asteroid and rare main-belt comet from the outermost regions of the asteroid belt, approximately 15 kilometers (9 miles) in diameter. It was discovered on 8 April 2008, by astronomers of the Spacewatch program at Kitt Peak National Observatory near Tucson, Arizona, in the United States. The presumably carbonaceous body has a rotation period of 10.7 hours.
2008 GO98 is classified as a member of the dynamical Hilda group, as well as a main-belt comet that shows clear cometary activity, which has also been described as a "quasi Hilda comet". Orbital backward integration suggests that it might have been a centaur or trans-Neptunian object that ended its dynamical evolution as a quasi Hilda comet.
It orbits the Sun in the outer asteroid belt at a distance of 2.9–5.1 AU once every 7 years and 11 months (2,883 days; semi-major axis of 3.96 AU). Its orbit has an eccentricity of 0.28 and an inclination of 16° with respect to the ecliptic. The body's observation arc begins with a precovery taken by the Sloan Digital Sky Survey in October 2001, more than 5 years prior to its official discovery observation by Spacewatch.
2008 GO98 has a Jupiter Tisserand's parameter (TJ) of 2.926, just below Jewitt's threshold of 3, which serves as a distinction between the main-belt asteroids (TJ larger than 3) and the Jupiter-family comets (TJ between 2 and 3).
In August 2017, a rotational lightcurve of 2008 GO98 was obtained from photometric observations by American astronomer Brian Warner at the Palmer Divide Station (U82) in California. Lightcurve analysis gave a rotation period of 10.74±0.01 hours with a small brightness amplitude of 0.12 magnitude (U=2).[a]
The Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous body of 0.057 and calculates a diameter of 14.64 kilometers based on an absolute magnitude of 12.9. Other estimates, taking into account several published magnitude measurements and a large range of albedo assumptions, estimate a diameter range of 5.5 to 24.7 kilometers.