1646 Rosseland

1646 Rosseland, provisional designation 1939 BG, is a stony asteroid from the inner regions of the asteroid belt, approximately 12 kilometers in diameter. It was discovered on 19 January 1939, by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland.^[12] It was later named after Norwegian astrophysicist Svein Rosseland.^[2]

1646 Rosseland

Discovery[1]
Discovered by	Y. Väisälä
Discovery site	Turku Obs.
Discovery date	19 January 1939
Designations
MPC designation	(1646) Rosseland
Named after	Svein Rosseland (astrophysicist)[2]
Alternative designations	1939 BG · 1937 QH 1948 QR · 1955 NB 1977 FK · 1980 ME
Minor planet category	main-belt · (inner)[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	79.69 yr (29,105 days)
Aphelion	2.6435 AU
Perihelion	2.0771 AU
Semi-major axis	2.3603 AU
Eccentricity	0.1200
Orbital period (sidereal)	3.63 yr (1,324 days)
Mean anomaly	320.86°
Mean motion	0° 16m 18.48s / day
Inclination	8.3787°
Longitude of ascending node	119.98°
Argument of perihelion	279.82°
Physical characteristics
Dimensions	11.48±3.28 km[4] 11.50±2.88 km[5] 12.130±0.007 km[6] 12.801±0.231 km[7] 12.85 km (calculated)[3] 13.49±0.27 km[8]
Synodic rotation period	68.9 h[9] 69.2 h[10]
Geometric albedo	0.18±0.10[5] 0.186±0.008[8] 0.19±0.07[4] 0.20 (assumed)[3] 0.202±0.030[7] 0.2253±0.0341[6]
Spectral type	S[3]
Absolute magnitude (H)	11.82[1][3][4][6][7][8] · 11.97±0.11[11] · 12.06[5]

Orbit and classification

The S-type asteroid orbits the Sun in the inner main-belt at a distance of 2.1–2.6 AU once every 3 years and 8 months (1,324 days). Its orbit has an eccentricity of 0.12 and an inclination of 8° with respect to the ecliptic.^[1] Rosseland was first observed at Johannesburg Observatory as 1937 QH, extending the body's observation arc by 2 years prior to its official discovery observation in 1939.^[12]

Physical characteristics

Photometry

American astronomer Richard Binzel obtained the first rotational lightcurve of Rosseland in the early 1980s. It gave a rotation period of 69.2 hours with a brightness variation of 0.13 magnitude (U=2).^[10] During a survey of presumed slow rotators, photometric observations by Brazilian Cláudia Angeli and colleges gave a period of 69.2 hours and an amplitude of 0.45 magnitude (U=1).^[9]

Diameter and albedo

According to the surveys carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Rosseland measures between 11.48 and 13.49 kilometers in diameter and its surface has an albedo between 0.18 and 0.2253.^{[4][5][6][7][8]} The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 12.85 kilometers with an absolute magnitude of 11.82.^[3]

Naming

This minor planet was named in honor of renowned Norwegian astrophysicist Svein Rosseland (1894–1985), founder and first director of the Institute for Theoretical Astrophysics in Oslo. His work on the theory of stellar interiors included studies of stellar rotation and stability and the derivation of the Rosseland mean opacity.^[2] The lunar crater Rosseland is also named after him. The official naming citation was published by the Minor Planet Center on 20 February 1976 (M.P.C. 3932).^[13]

References

1. "JPL Small-Body Database Browser: 1646 Rosseland (1939 BG)" (2017-05-04 last obs.). Jet Propulsion Laboratory. Retrieved 30 June 2017.
2. Schmadel, Lutz D. (2007). "(1646) Rosseland". Dictionary of Minor Planet Names – (1646) Rosseland. Springer Berlin Heidelberg. p. 131. doi:10.1007/978-3-540-29925-7_1647. ISBN 978-3-540-00238-3.
3. "LCDB Data for (1646) Rosseland". Asteroid Lightcurve Database (LCDB). Retrieved 26 December 2016.
4. Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. S2CID 9341381. Retrieved 26 December 2016.
5. Nugent, C. R.; Mainzer, A.; Bauer, J.; Cutri, R. M.; Kramer, E. A.; Grav, T.; et al. (September 2016). "NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos". The Astronomical Journal. 152 (3): 12. arXiv:1606.08923. Bibcode:2016AJ....152...63N. doi:10.3847/0004-6256/152/3/63.
6. 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. S2CID 35447010.
7. 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. S2CID 46350317. Retrieved 26 December 2016.
8. 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)
9. Angeli, C. A.; Lazzaro, D.; Florczak, M. A.; Betzler, A. S.; Carvano, J. M. (May 1999). "A contribution to the study of asteroids with longrotational period". Planetary and Space Science. 47 (5): 699–714. Bibcode:1999P&SS...47..699A. doi:10.1016/S0032-0633(98)00122-6. Retrieved 26 December 2016.
10. Binzel, R. P.; Mulholland, J. D. (December 1983). "A photoelectric lightcurve survey of small main belt asteroids". Icarus. 56 (3): 519–533. Bibcode:1983Icar...56..519B. doi:10.1016/0019-1035(83)90170-7. ISSN 0019-1035. Retrieved 26 December 2016.
11. 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. S2CID 53493339. Retrieved 26 December 2016.
12. "1646 Rosseland (1939 BG)". Minor Planet Center. Retrieved 26 December 2016.
13. 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. Bibcode:2009dmpn.book.....S. doi:10.1007/978-3-642-01965-4. ISBN 978-3-642-01964-7.

External links

• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 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
• 1646 Rosseland at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 1646 Rosseland at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters