Astronomy:2391 Tomita

From HandWiki
Short description: Nysian asteroid from the inner regions of the asteroid belt
2391 Tomita
Discovery [1]
Discovered byK. Reinmuth
Discovery siteHeidelberg Obs.
Discovery date9 January 1957
Designations
(2391) Tomita
Named afterKōichirō Tomita
(Japanese astronomer)[2]
1957 AA · 1929 VX
1938 BF · 1942 DF
1957 BA · 1977 KM
1978 PA4 · 1980 DC6
Minor planet categorymain-belt · Nysa [3]
Orbital characteristics [1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc87.07 yr (31,804 days)
|{{{apsis}}}|helion}}2.7676 AU
|{{{apsis}}}|helion}}2.1141 AU
2.4408 AU
Eccentricity0.1339
Orbital period3.81 yr (1,393 days)
Mean anomaly345.07°
Mean motion0° 15m 30.6s / day
Inclination3.0111°
Longitude of ascending node163.32°
282.65°
Physical characteristics
Dimensions9.17 km (calculated)[3]
15.07±4.33 km[4]
15.20±3.74 km[5]
16.62±0.23 km[6]
17.941±0.129[7]
19.412±0.175 km[8]
Rotation period7.9533±0.0005 h[lower-alpha 1]
8.435±0.079 h[lower-alpha 2]
Geometric albedo0.0321±0.0044[8]
0.06±0.03[5]
0.070±0.004[6]
0.07±0.07[4][7]
0.21 (assumed)[3]
S [3] · C [9]
Absolute magnitude (H)12.4[4][6][8] · 12.5[1][3] · 12.66[5] · 12.74±0.28[9]


2391 Tomita, provisional designation 1957 AA, is a Nysian asteroid from the inner regions of the asteroid belt, approximately 15 kilometers in diameter. The asteroid was discovered on 9 January 1957, by German astronomer Karl Reinmuth at Heidelberg Observatory in southern Germany.[10] It was named after Japanese astronomer Kōichirō Tomita.[2]

Orbit and classification

Tomita is a member of the Nysa family, which is named after its most massive member 44 Nysa. It orbits the Sun in the inner main-belt at a distance of 2.1–2.8 AU once every 3 years and 10 months (1,393 days). Its orbit has an eccentricity of 0.13 and an inclination of 3° with respect to the ecliptic.[1]

A first precovery was taken at Lowell Observatory in 1929, extending the body's observation arc by 28 years prior to its official discovery observation at Heidelberg.[10]

Physical characteristics

Tomita has been characterized as a stony S-type asteroid by the Collaborative Asteroid Lightcurve Link (CALL), and as a carbonaceous C-type asteroid by Pan-STARRS' photometric survey.[3][9]

Diameter and albedo

According to the surveys carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, the asteroid measures between 15.07 and 19.4 kilometers in diameter and its surface has a low albedo between 0.03 and 0.07, respectively.[4][5][6][7][8]

As CALL considers the body to be of a stony composition, it assumes a much higher albedo of 0.21 and calculates a diameter of 9.2 kilometers, as the higher the asteroid's reflectivity (albedo), the shorter its diameter at a constant absolute magnitude (brightness).[3]

Rotation period

In December 2013, two rotational lightcurves were obtained for this asteroid from photometric observations. They gave a rotation period of 7.9533±0.0005 and 8.435±0.079 hours with a brightness variation of 0.14 and 0.15 in magnitude, respectively. ({{{1}}}).[lower-alpha 1][lower-alpha 2]

Naming

This minor planet was named in honor of Japanese astronomer Kōichirō Tomita (1925–2006), long-time observer at the Tokyo Astronomical Observatory, and a discoverer of minor planets and comets himself. Tomita was also known as one of Japan's principal popularizer of astronomy.[2] The official naming citation was published by the Minor Planet Center on 14 April 1987 (M.P.C. 11748).[11]

Notes

  1. ↑ 1.0 1.1 Pravec (2013) web: lightcurve plot with a rotation period 7.9533±0.0005 hours with a brightness amplitude of 0.14 mag. Summary figures for (2391) Tomita at Collaborative Asteroid Lightcurve Link (CALL) and Pravec, P.; Wolf, M.; Sarounova, L. (2013)
  2. ↑ 2.0 2.1 Williams (2013) web: rotation period 8.435±0.079 hours with a brightness amplitude of 0.15 mag. Summary figures for (2391) Tomita at Collaborative Asteroid Lightcurve Link (CALL). Data by Williams, R. (2013), posted on CALL page.

References

  1. ↑ 1.0 1.1 1.2 1.3 "JPL Small-Body Database Browser: 2391 Tomita (1957 AA)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2002391. Retrieved 13 June 2017. 
  2. ↑ 2.0 2.1 2.2 Schmadel, Lutz D. (2007). "(2391) Tomita". Dictionary of Minor Planet Names – (2391) Tomita. Springer Berlin Heidelberg. p. 195. doi:10.1007/978-3-540-29925-7_2392. ISBN 978-3-540-00238-3. 
  3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 "LCDB Data for (2391) Tomita". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=2391%7CTomita. Retrieved 14 August 2016. 
  4. ↑ 4.0 4.1 4.2 4.3 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. doi:10.1088/0004-637X/814/2/117. Bibcode: 2015ApJ...814..117N. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015ApJ...814..117N. Retrieved 13 June 2017. 
  5. ↑ 5.0 5.1 5.2 5.3 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. doi:10.3847/0004-6256/152/3/63. Bibcode: 2016AJ....152...63N. 
  6. ↑ 6.0 6.1 6.2 6.3 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. doi:10.1088/2041-8205/759/1/L8. Bibcode: 2012ApJ...759L...8M. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012ApJ...759L...8M. Retrieved 14 August 2016. 
  7. ↑ 7.0 7.1 7.2 Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R. et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal 791 (2): 11. doi:10.1088/0004-637X/791/2/121. Bibcode: 2014ApJ...791..121M. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2014ApJ...791..121M. Retrieved 7 December 2016. 
  8. ↑ 8.0 8.1 8.2 8.3 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. doi:10.1088/0004-637X/741/2/90. Bibcode: 2011ApJ...741...90M. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011ApJ...741...90M. Retrieved 14 August 2016. 
  9. ↑ 9.0 9.1 9.2 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. doi:10.1016/j.icarus.2015.08.007. Bibcode: 2015Icar..261...34V. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015Icar..261...34V. Retrieved 14 August 2016. 
  10. ↑ 10.0 10.1 "2391 Tomita (1957 AA)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=2391. Retrieved 14 August 2016. 
  11. ↑ "MPC/MPO/MPS Archive". Minor Planet Center. https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html. Retrieved 14 August 2016. 

External links



Retrieved from "https://handwiki.org/wiki/index.php?title=Astronomy:2391_Tomita&oldid=3428784"