1760 Sandra, provisional designation 1950 GB, is a carbonaceous asteroid from the outer regions of the asteroid belt, approximately 35 kilometers in diameter. It was discovered on 10 April 1950, by South African astronomer Ernest Johnson at Union Observatory in Johannesburg, and named after his granddaughter Sandra.[2][11]

1760 Sandra
Discovery[1]
Discovered byErnest Johnson
Discovery siteJohannesburg Obs.
Discovery date10 April 1950
Designations
(1760) Sandra
Named after
Sandra (discoverer's granddaughter)[2]
1950 GB · 1934 NP
1935 QH · 1950 HF
1950 JM · 1951 OK
1967 JC · 1968 OC
main-belt · (outer)[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc81.66 yr (29,826 days)
Aphelion3.5564 AU
Perihelion2.7418 AU
3.1491 AU
Eccentricity0.1293
5.59 yr (2,041 days)
6.2435°
0° 10m 35.04s / day
Inclination8.4403°
232.61°
332.93°
Physical characteristics
Dimensions33.989±0.214 km[4]
34.765±0.454 km[5]
35.89±3.5 km[6]
36.03 km (derived)[3]
36.64±1.03 km[7]
37.71±0.64 km[8]
6.5668±0.0004 h[9]
0.034±0.002[7]
0.0345±0.008[6]
0.0385±0.0055[4]
0.054±0.011[8]
0.0542 (derived)[3]
C[3]
10.90[8] · 11.0[1][3] · 11.23±0.27[10] · 11.5[4][6][7]

Orbit and classification

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Sandra is a carbonaceous C-type asteroid that orbits the Sun in the outer main-belt at a distance of 2.7–3.6 AU once every 5 years and 7 months (2,041 days). Its orbit has an eccentricity of 0.13 and an inclination of 8° with respect to the ecliptic.[1] It was first identified as 1934 NP at the discovering observatory. The body's observation arc begins with its identification as 1935 QH at Heidelberg in 1935, or 15 years prior to its official discovery observation at Johannesburg.[11]

Lightcurve

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In April 2006, a rotational lightcurve of Sandra was obtained from photometric observations by French amateur astronomer Pierre Antonini. Lightcurve analysis gave a well-defined rotation period of 6.5668 hours with a brightness variation of 0.42 magnitude (U=3).[9]

Diameter and albedo

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According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Sandra measures between 33.989 and 37.71 kilometers in diameter and its surface has an albedo between 0.034 and 0.054.[4][5][6][7][8] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0542 and a diameter of 36.03 kilometers with on an absolute magnitude of 11.0.[3]

Naming

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This minor planet was named by the South African discover Ernest Johnson after his granddaughter Sandra.[2] The official naming citation was published by the Minor Planet Center on 20 February 1976 (M.P.C. 3934).[12]

References

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  1. ^ a b c d "JPL Small-Body Database Browser: 1760 Sandra (1950 GB)" (2017-04-28 last obs.). Jet Propulsion Laboratory. Retrieved 1 July 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(1760) Sandra". Dictionary of Minor Planet Names – (1760) Sandra. Springer Berlin Heidelberg. p. 140. doi:10.1007/978-3-540-29925-7_1761. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f "LCDB Data for (1760) Sandra". Asteroid Lightcurve Database (LCDB). Retrieved 4 April 2017.
  4. ^ a b c d 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.
  5. ^ a b 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. arXiv:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. Retrieved 4 April 2017.
  6. ^ a b c d Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System. 12: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T. Retrieved 22 October 2019.
  7. ^ a b c d 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)
  8. ^ a b c d 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.
  9. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1760) Sandra". Geneva Observatory. Retrieved 4 April 2017.
  10. ^ 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.
  11. ^ a b "1760 Sandra (1950 GB)". Minor Planet Center. Retrieved 4 April 2017.
  12. ^ Schmadel, Lutz D. "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.
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