Astronomy:39890 Bobstephens
| Discovery [1] | |
|---|---|
| Discovered by | P. Pravec |
| Discovery site | Ondřejov Obs. |
| Discovery date | 23 March 1998 |
| Designations | |
| (39890) Bobstephens | |
| Named after | Robert D. Stephens (American astronomer)[2] |
| 1998 FA3 | |
| Minor planet category | main-belt · (middle) |
| Orbital characteristics [1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 21.25 yr (7,760 days) |
| |{{{apsis}}}|helion}} | 3.1534 AU |
| |{{{apsis}}}|helion}} | 2.0287 AU |
| 2.5910 AU | |
| Eccentricity | 0.2170 |
| Orbital period | 4.17 yr (1,523 days) |
| Mean anomaly | 201.46° |
| Mean motion | 0° 14m 10.68s / day |
| Inclination | 5.4950° |
| Longitude of ascending node | 161.73° |
| 95.752° | |
| Physical characteristics | |
| Dimensions | 2.06 km (calculated)[3] |
| Rotation period | 9.55±0.01 h[4] |
| Geometric albedo | 0.20 (assumed)[3] |
| S [3] | |
| Absolute magnitude (H) | 15.8[3] · 15.9[1] |
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.[5] It was named for American astronomer Robert Stephens.[2]
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.[1] 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.[5]
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 ({{{1}}}).[4]
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.[3]
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.[2] The official naming citation was published by the Minor Planet Center on 24 July 2002 (M.P.C. 46112).[6]
References
- ↑ 1.0 1.1 1.2 1.3 "JPL Small-Body Database Browser: 39890 Bobstephens (1998 FA3)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2039890.
- ↑ 2.0 2.1 2.2 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.
- ↑ 3.0 3.1 3.2 3.3 3.4 "LCDB Data for (39890) Bobstephens". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=39890%7CBobstephens.
- ↑ 4.0 4.1 Coley, Daniel (January 2012). "Asteroid Lightcurve Analysis at the Danhenge Observatory Apr - Aug 2011". The Minor Planet Bulletin 39 (1): 23–24. ISSN 1052-8091. Bibcode: 2012MPBu...39...23C. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012MPBu...39...23C. Retrieved 27 December 2016.
- ↑ 5.0 5.1 "39890 Bobstephens (1998 FA3)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=39890.
- ↑ "MPC/MPO/MPS Archive". Minor Planet Center. https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html.
External links
- Asteroid Lightcurve Database (LCDB), query form (info )
- 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
- 39890 Bobstephens at the JPL Small-Body Database
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