Misplaced Pages

39890 Bobstephens (provisional designation 1998 FA₃) is a stony asteroid from the middle region of the asteroid belt, approximately 2 kilometers in diameter. The asteroid was discovered on 23 March 1998, by Czech astronomer Petr Pravec at Ondřejov Observatory near Prague in the Czech Republic. It was named for American astronomer Robert Stephens.

Orbit and classification

Bobstephens orbits the Sun in the central main-belt at a distance of 2.0–3.2 AU once every 4 years and 2 months (1,523 days). Its orbit has an eccentricity of 0.22 and an inclination of 5° with respect to the ecliptic. It was first imaged at Steward Observatory in 1995. This precovery extends the body's observation arc by 3 years prior to its official discovery observation.

Physical characteristics

Rotation period

In August 2008, a rotational lightcurve of Bobstephens was obtained from photometric observations by American amateur astronomer Daniel Coley at the Center for Solar System Studies in California. Light-curve analysis gave a rotation period of 9.55 hours with a brightness variation of 0.20 magnitude (U=2).

Diameter and albedo

The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 2.06 kilometers with an absolute magnitude of 15.8.

Naming

This minor planet was named for Californian amateur astronomer and photometrist Robert D. Stephens (born 1955), who is an expert in lightcurve photometry of minor planets since 1999. The official naming citation was published by the Minor Planet Center on 24 July 2002 (M.P.C. 46112).

References

1. ^ "JPL Small-Body Database Browser: 39890 Bobstephens (1998 FA3)" (2017-01-23 last obs.). Jet Propulsion Laboratory. Retrieved 28 June 2017.
2. ^ Schmadel, Lutz D. (2007). "(39890) Bobstephens". Dictionary of Minor Planet Names – (39890) Bobstephens. Springer Berlin Heidelberg. p. 894. doi:10.1007/978-3-540-29925-7_10020. ISBN 978-3-540-00238-3.
3. ^ "LCDB Data for (39890) Bobstephens". Asteroid Lightcurve Database (LCDB). Retrieved 27 December 2016.
4. ^ Coley, Daniel (January 2012). "Asteroid Lightcurve Analysis at the Danhenge Observatory Apr - Aug 2011". The Minor Planet Bulletin. 39 (1): 23–24. Bibcode:2012MPBu...39...23C. ISSN 1052-8091. Retrieved 27 December 2016.
5. ^ "39890 Bobstephens (1998 FA3)". Minor Planet Center. Retrieved 27 December 2016.
6. "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 27 December 2016.

External links

• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Discovery Circumstances: Numbered Minor Planets (35001)-(40000) – Minor Planet Center
• 39890 Bobstephens at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 39890 Bobstephens at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters

• Minor planet object articles (numbered)
• Background asteroids
• Discoveries by Petr Pravec
• Named minor planets
• Astronomical objects discovered in 1998