astro.wikisort.org - Asteroid

(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.[1] The presumably carbonaceous body has a rotation period of 10.7 hours.[5]

(457175) 2008 GO₉₈
362P/2008 GO₉₈

Discovery[1]
Discovered by	Spacewatch
Discovery site	Kitt Peak National Obs.
Discovery date	8 April 2008
Designations
MPC designation	(457175) 2008 GO98
Alternative designations	2008 GO98 · 362P
Minor planet category	main-belt · (outer)[2] main-belt comet[3][4] Hilda[1][5]
Orbital characteristics[2]
Epoch 4 December 2015 (JD 2457360.5)
Uncertainty parameter 0
Observation arc	16.05 yr (5,862 d)
Aphelion	5.0787 AU
Perihelion	2.8506 AU
Semi-major axis	3.9646 AU
Eccentricity	0.2810
Orbital period (sidereal)	7.89 yr (2,883 d)
Mean anomaly	327.18°
Mean motion	0° 7m 29.64s / day
Inclination	15.569°
Longitude of ascending node	192.61°
Argument of perihelion	53.287°
Jupiter MOID	0.3592 AU
TJupiter	2.9260
Physical characteristics
Mean diameter	5.5–24.7 km (est.)[6] 14.64 h (calculated)[5]
Synodic rotation period	10.74±0.01 h[5][lower-alpha 1]
Geometric albedo	0.057 (assumed)[5]
Spectral type	C (assumed)[5]
Absolute magnitude (H)	12.9[1][2][5] 15.1[4]

Orbit and classification

2008 GO₉₈ is classified as a member of the dynamical Hilda group,[5] as well as a main-belt comet that shows clear cometary activity,[3][6] which has also been described as a "quasi Hilda comet".[4] 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.[4] It may have reached the belt during the last few hundred years.[7]

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.[2] 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.[1]

2008 GO₉₈ has a Jupiter Tisserand's parameter (T_J) of 2.926,[2] just below Jewitt's threshold of 3, which serves as a distinction between the main-belt asteroids (T_J larger than 3) and the Jupiter-family comets (T_J between 2 and 3).[8]

Numbering and naming

This minor planet was numbered by the Minor Planet Center on 16 February 2016 (M.P.C. 98587).[9] As of 2020, it has not been named.[1]

Physical characteristics

2008 GO₉₈ is an assumed C-type asteroid.[5]

Rotation period

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).[5][lower-alpha 1]

Diameter and albedo

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.[5] 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.[6]

Notes

References

External links

• COMETARY ACTIVITY IN (457175) 2008 GO98, Minor Planet Electronic Circular, Minor Planet Center
• It's an Asteroid, It's a Comet, It's... well, Both for Now!, Catalina Sky Survey, Lunar and Planetary Laboratory
• Cometary activity in (457175) 2008 GO98, The Virual Telescope, 23 August 2017
• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Discovery Circumstances: Numbered Minor Planets (455001)-(460000) – Minor Planet Center
• (457175) 2008 GO98 at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• (457175) 2008 GO98 at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

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