Astronomy:1708 Pólit

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1708 Pólit
Discovery[1]
Discovered byJ. Comas Solà
Discovery siteFabra Obs.
Discovery date30 November 1929
Designations
(1708) Pólit
Named afterIsidre Pòlit
(Catalan astronomer)[2]
1929 XA · 1934 XF
1939 YB
Minor planet categorymain-belt · (outer)[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc87.51 yr (31,964 days)
|{{{apsis}}}|helion}}3.8064 AU
|{{{apsis}}}|helion}}2.0159 AU
2.9111 AU
Eccentricity0.3075
Orbital period4.97 yr (1,814 days)
Mean anomaly213.43°
Mean motion0° 11m 54.24s / day
Inclination6.0445°
Longitude of ascending node192.21°
248.96°
Physical characteristics
Dimensions27.46±1.30 km[4]
28.06±6.19 km[5]
28.706±0.057 km[6]
29.30±1.7 km[3][7]
30.282±0.071 km[8]
33.44±1.53 km[9]
Rotation period7.5080±0.0002 h[10][11]
7.5085±0.001 h[12]
7.520±0.002 h[13]
Geometric albedo0.035±0.004[9]
0.0350±0.0055[8]
0.0392±0.005[7]
0.04±0.01[4][5]
0.042±0.008[6]
C[3]
Absolute magnitude (H)11.70[5] · 11.8[1][3][7][8][9] · 11.86[4]


1708 Pólit, provisional designation 1929 XA, is a very dark asteroid from the outer region of the asteroid belt, approximately 29 kilometers in diameter. It was discovered on 30 November 1929, by Spanish astronomer of Catalan origin Josep Comas i Solà at the Fabra Observatory in Barcelona, and was later named after Catalan astronomer Isidre Pòlit i Boixareu.[14]

Orbit and classification

Pólit orbits the Sun in the outer main-belt at a distance of 2.0–3.8 AU once every 4 years and 12 months (1,814 days). Its orbit has an eccentricity of 0.31 and an inclination of 6° with respect to the ecliptic.[1] A first precovery was taken at Lowell Observatory in Flagstaff, extending the body's observation arc by 3 days prior to its official discovery observation.[14]

Physical characteristics

The asteroid has been characterized as a C-type asteroid.[3]

Diameter and albedo

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, Pólit measures between 27.46 and 33.44 kilometers in diameter and its surface has a low albedo between 0.035 and 0.042.[4][5][6][7][8][9]

The Collaborative Asteroid Lightcurve Link agrees with the results obtained by IRAS, that is, an albedo of 0.0392 and a diameter of 29.30 kilometers based on an absolute magnitude of 11.8.[3]

Lightcurves

Between 2005 and 2014, a large number of rotational lightcurves of Pólit were obtained from photometric observations by American astronomer Maurice Clark at the Preston Gott and McDonald Observatories. Lightcurve analysis gave a rotation period of 7.5080 to 7.5085 hours with a brightness variation between 0.40 and 0.50 magnitude ({{{1}}}).[10][11][12] Clark also derived a spin axis of (2.1°, 47.5°) in ecliptic coordinates (λ, β) ({{{1}}}).[11]

In addition, astronomer Raymond Poncy measured a period of 7.520 hours with an amplitude of 0.30 magnitude ({{{1}}}).[13]

Naming

This minor planet was named in memory of the Fabra Observatory's second director of the astronomical section, Isidre Pòlit i Boixareu (1880–1958), who was an assiduous observer of minor planets and comets.[2] The official naming citation was published by the Minor Planet Center on 1 June 1980 (M.P.C. 5357).[15]

References

  1. 1.0 1.1 1.2 1.3 "JPL Small-Body Database Browser: 1708 Polit (1929 XA)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001708. Retrieved 4 August 2017. 
  2. 2.0 2.1 Schmadel, Lutz D. (2007). "(1708) Pólit". Dictionary of Minor Planet Names – (1708) Pólit. Springer Berlin Heidelberg. p. 136. doi:10.1007/978-3-540-29925-7_1709. ISBN 978-3-540-00238-3. 
  3. 3.0 3.1 3.2 3.3 3.4 3.5 "LCDB Data for (1708) Pólit". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=1708%7CPólit. Retrieved 4 August 2017. 
  4. 4.0 4.1 4.2 4.3 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. Bibcode2016AJ....152...63N. 
  5. 5.0 5.1 5.2 5.3 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. Bibcode2015ApJ...814..117N. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015ApJ...814..117N. Retrieved 4 August 2017. 
  6. 6.0 6.1 6.2 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. Bibcode2014ApJ...791..121M. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2014ApJ...791..121M. Retrieved 4 August 2017. 
  7. 7.0 7.1 7.2 7.3 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. Bibcode2004PDSS...12.....T. https://sbnarchive.psi.edu/pds3/iras/IRAS_A_FPA_3_RDR_IMPS_V6_0/data/diamalb.tab. Retrieved 22 October 2019. 
  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. Bibcode2011ApJ...741...90M. 
  9. 9.0 9.1 9.2 9.3 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)
  10. 10.0 10.1 Clark, Maurice (July 2015). "Asteroid Photometry from the Preston Gott Observatory". The Minor Planet Bulletin 42 (3): 163–166. ISSN 1052-8091. Bibcode2015MPBu...42..163C. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015MPBu...42..163C. Retrieved 4 August 2017. 
  11. 11.0 11.1 11.2 Clark, Maurice (January 2016). "Shape Modelling of Asteriods [sic 1708 Polit, 2036 Sheragul, and 3015 Candy"]. The Minor Planet Bulletin 43 (1): 80–86. ISSN 1052-8091. Bibcode2016MPBu...43...80C. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2016MPBu...43...80C. Retrieved 4 August 2017. 
  12. 12.0 12.1 Clark, Maurice (October 2011). "Asteroid Lightcurves from the Preston Gott and McDonald Observatories". The Minor Planet Bulletin 38 (4): 187–189. ISSN 1052-8091. Bibcode2011MPBu...38..187C. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011MPBu...38..187C. Retrieved 4 August 2017. 
  13. 13.0 13.1 Behrend, Raoul. "Asteroids and comets rotation curves – (1708) Pólit". Geneva Observatory. http://obswww.unige.ch/~behrend/page4cou.html#001708. Retrieved 4 August 2017. 
  14. 14.0 14.1 "1708 Polit (1929 XA)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=1708. Retrieved 4 August 2017. 
  15. "MPC/MPO/MPS Archive". Minor Planet Center. https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html. Retrieved 4 August 2017. 

External links