Astronomy:1349 Bechuana

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1349 Bechuana
001349-asteroid shape model (1349) Bechuana.png
Shape model of Bechuana from its lightcurve
Discovery[1]
Discovered byC. Jackson
Discovery siteJohannesburg Obs.
Discovery date13 June 1934
Designations
(1349) Bechuana
Named afterBechuanaland[2]
(now Republic of Botswana)
1934 LJ · 1934 NH
1950 PA · 1950 QO
Minor planet categorymain-belt · (outer)[3]
background[4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc83.06 yr (30,338 days)
|{{{apsis}}}|helion}}3.4872 AU
|{{{apsis}}}|helion}}2.5416 AU
3.0144 AU
Eccentricity0.1569
Orbital period5.23 yr (1,912 days)
Mean anomaly336.81°
Mean motion0° 11m 17.88s / day
Inclination10.049°
Longitude of ascending node307.12°
305.30°
Physical characteristics
Dimensions23.773±0.282 km[5]
24.249±0.334 km[6]
25.80±0.37 km[7]
28.57±1.17 km[8]
46.30 km (calculated)[3]
Rotation period15.681±0.0099 h[9]
15.6873±0.0001 h[10]
15.692±0.002 h[11]
Geometric albedo0.057 (assumed)[3]
0.150±0.024[8]
0.233±0.008[7]
0.2610±0.0357[5]
CX[12] · C (assumed)[3]
Absolute magnitude (H)10.20[5][7] · 10.23±0.44[12] · 10.250±0.002 (R)[9] · 10.40[3][8] · 10.5[1]


1349 Bechuana, provisional designation 1934 LJ, is a background asteroid from the outer regions of the asteroid belt, approximately 26 kilometers in diameter. It was discovered on 13 June 1934, by South-African astronomer Cyril Jackson at the Union Observatory in Johannesburg.[13] The asteroid was named for the former Bechuanaland, what is now the Republic of Botswana.[2]

Orbit and classification

Bechuana is a non-family asteroid from the main belt's background population.[4] It orbits the Sun in the outer asteroid belt at a distance of 2.5–3.5 AU once every 5 years and 3 months (1,912 days; semi-major axis of 3.01 AU). Its orbit has an eccentricity of 0.16 and an inclination of 10° with respect to the ecliptic.[1] The body's observation arc begins with its official discovery observation at Johannesburg in June 1934.[13]

Physical characteristics

Bechuana has been characterized as both a C-type and X-type asteroid by Pan-STARRS photometric survey. The Collaborative Asteroid Lightcurve Link (CALL) assumes it to be a carbonaceous C-type.[3]

Rotation period

In December 2010, a rotational lightcurve of Bechuana was obtained from photometric observations by astronomers at the Palomar Transient Factory in California. Lightcurve analysis gave a rotation period of 15.681 hours with a brightness variation of 0.29 magnitude ({{{1}}}).[9] In January 2011, astronomers Pierre Antonini and Silvano Casulli measured a refined period of 15.692 hours with an amplitude of 0.30 ({{{1}}}).[11]

Poles

A 2016-published lightcurve, using modeled photometric data from the Lowell Photometric Database, gave a concurring period of 15.6873 hours and determined two spin axis in ecliptic coordinates (λ, β) of (153.0°, 32.0°) and (314.0°, 46.0°).[10]

Diameter and albedo

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Bechuana measures between 23.773 and 28.57 kilometers in diameter and its surface has an albedo between 0.150 and 0.2610.[5][6][7][8]

CALL assumes a standard albedo for carbonaceous asteroids of 0.057 and consequently calculates a much larger diameter of 46.30 kilometers based on an absolute magnitude of 10.4.[3]

Naming

This minor planet was named after the Bechuanaland, a British Protectorate from 1884 to 1966 and what is now the Republic of Botswana, north of South Africa. The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 122).[2]

References

  1. 1.0 1.1 1.2 1.3 "JPL Small-Body Database Browser: 1349 Bechuana (1934 LJ)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001349. 
  2. 2.0 2.1 2.2 Schmadel, Lutz D. (2007). "(1349) Bechuana". Dictionary of Minor Planet Names – (1349) Bechuana. Springer Berlin Heidelberg. p. 110. doi:10.1007/978-3-540-29925-7_1350. ISBN 978-3-540-00238-3. 
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 "LCDB Data for (1349) Bechuana". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=1349%7CBechuana. 
  4. 4.0 4.1 "Asteroid 1349 Bechuana – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. https://newton.spacedys.com/astdys/index.php?pc=1.1.6&n=1349. 
  5. 5.0 5.1 5.2 5.3 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. Bibcode2011ApJ...741...90M. 
  6. 6.0 6.1 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. doi:10.1088/0004-637X/741/2/68. Bibcode2011ApJ...741...68M. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011ApJ...741...68M. Retrieved 16 November 2017. 
  7. 7.0 7.1 7.2 7.3 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. doi:10.1093/pasj/63.5.1117. Bibcode2011PASJ...63.1117U.  (online, AcuA catalog p. 153)
  8. 8.0 8.1 8.2 8.3 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. Bibcode2012ApJ...759L...8M. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012ApJ...759L...8M. Retrieved 16 November 2017. 
  9. 9.0 9.1 9.2 Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal 150 (3): 35. doi:10.1088/0004-6256/150/3/75. Bibcode2015AJ....150...75W. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015AJ....150...75W. Retrieved 16 November 2017. 
  10. 10.0 10.1 Durech, J.; Hanus, J.; Oszkiewicz, D.; Vanco, R. (March 2016). "Asteroid models from the Lowell photometric database". Astronomy and Astrophysics 587: 6. doi:10.1051/0004-6361/201527573. Bibcode2016A&A...587A..48D. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2016A&A...587A..48D. Retrieved 16 November 2017. 
  11. 11.0 11.1 Behrend, Raoul. "Asteroids and comets rotation curves – (1349) Bechuana". Geneva Observatory. http://obswww.unige.ch/~behrend/page4cou.html#001349. 
  12. 12.0 12.1 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. Bibcode2015Icar..261...34V. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015Icar..261...34V. Retrieved 16 November 2017. 
  13. 13.0 13.1 "1349 Bechuana (1934 LJ)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=1349. 

External links