Modelled shape of Angara from its lightcurve | |
Discovery | |
---|---|
Discovered by | L. Chernykh |
Discovery site | Crimean Astrophysical Obs. |
Discovery date | 1 April 1970 |
Designations | |
MPC designation | (1957) Angara |
Named after | Angara River (Siberian river) |
Alternative designations | 1970 GF · 1962 WG1 1969 AA |
Minor planet category | main-belt · Eos |
Orbital characteristics | |
Epoch 4 September 2017 (JD 2458000.5) | |
Uncertainty parameter 0 | |
Observation arc | 60.58 yr (22,126 days) |
Aphelion | 3.1828 AU |
Perihelion | 2.8338 AU |
Semi-major axis | 3.0083 AU |
Eccentricity | 0.0580 |
Orbital period (sidereal) | 5.22 yr (1,906 days) |
Mean anomaly | 345.36° |
Mean motion | 0° 11 20.04 / day |
Inclination | 11.191° |
Longitude of ascending node | 50.702° |
Argument of perihelion | 209.03° |
Physical characteristics | |
Dimensions | 17.907±0.108 km 18.189±0.229 km 18.38 km (derived) 21.44±0.70 km 30.41±0.58 km |
Synodic rotation period | 3.67 h |
Geometric albedo | 0.055±0.006 0.111±0.008 0.14 (assumed) 0.1438±0.0310 |
Spectral type | S B–V = 0.900 U–B = 0.380 |
Absolute magnitude (H) | 11.16±0.34 · 11.36 · 11.43 |
1957 Angara (prov. designation: 1970 GF) is a stony Eos asteroid from the outer regions of the asteroid belt, approximately 18 kilometers (11 miles) in diameter. It was discovered on 1 April 1970, by Soviet astronomer Lyudmila Chernykh at the Crimean Astrophysical Observatory in Nauchnyj, and named after the Siberian Angara River.
Classification and orbit
Angara is a member of the Eos family, well known for mostly being of a silicaceous composition. It orbits the Sun in the outer main-belt at a distance of 2.8–3.2 AU once every 5 years and 3 months (1,906 days). Its orbit has an eccentricity of 0.06 and an inclination of 11° with respect to the ecliptic. A first precovery was taken at Goethe Link Observatory in 1956, extending the body's observation arc by 14 years prior to its official discovery observation at Nauchnyj.
Naming
This minor planet was named for the over 1000-mile long Siberian Angara River that drains Lake Baikal. The official naming citation was published by the Minor Planet Center on 30 June 1977 (M.P.C. 4190).
Physical characteristics
In December 1983, a rotational lightcurve of Angara was obtained from photometric observations by American astronomer Richard Binzel. Lightcurve analysis gave a well-define rotation period of 3.67 hours with a brightness amplitude of 0.52 magnitude, indicative of a non-spheroidal shape (U=3). Binzel also classified the body as a stony S-type asteroid.
According to the surveys carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Angara measures between 17.907 and 30.41 kilometers in diameter and its surface has an albedo between 0.055 and 0.1438. The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony Eoan asteroids of 0.14 – taken from the family's largest member and namesake, 221 Eos – and derives a diameter of 18.38 kilometers with an absolute magnitude of 11.43.
References
- ^ "JPL Small-Body Database Browser: 1957 Angara (1970 GF)" (2017-06-02 last obs.). Jet Propulsion Laboratory. Retrieved 2 July 2017.
- ^ Schmadel, Lutz D. (2007). "(1957) Angara". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 157. doi:10.1007/978-3-540-29925-7_1958. ISBN 978-3-540-00238-3.
- ^ "LCDB Data for (1957) Angara". Asteroid Lightcurve Database (LCDB). Retrieved 4 April 2017.
- ^ Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 4 April 2017.
- ^ Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90.
- ^ Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. (online, AcuA catalog p. 153)
- ^ Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C.; et al. (November 2012). "Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids". The Astrophysical Journal Letters. 759 (1): 5. arXiv:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 4 April 2017.
- ^ Binzel, R. P. (October 1987). "A photoelectric survey of 130 asteroids". Icarus. 72 (1): 135–208. Bibcode:1987Icar...72..135B. doi:10.1016/0019-1035(87)90125-4. ISSN 0019-1035. Retrieved 4 April 2017.
- Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 4 April 2017.
- ^ "1957 Angara (1970 GF)". Minor Planet Center. Retrieved 4 April 2017.
- Schmadel, Lutz D. (2009). "Appendix – Publication Dates of the MPCs". Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008). Springer Berlin Heidelberg. p. 221. doi:10.1007/978-3-642-01965-4. ISBN 978-3-642-01964-7.
External links
- Asteroid Lightcurve Database (LCDB), query form (info Archived 21 July 2011 at the Wayback Machine)
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
- Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
- 1957 Angara at AstDyS-2, Asteroids—Dynamic Site
- 1957 Angara at the JPL Small-Body Database
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