925 Alphonsina, provisional designation 1920 GM, is a stony Hansian asteroid from the central region of the asteroid belt, approximately 58 kilometers (36 miles) in diameter. It was discovered on 13 January 1920, by Catalan astronomer Josep Comas i Solà at the Fabra Observatory in Barcelona, Spain.[1] The S-type asteroid has a rotation period of 7.88 hours.[9] It was named for the Spanish Kings Alfonso X and Alfonso XIII.[20]
Orbit and classification
Together with asteroid 480 Hansa, Alphonsina is the largest member of the stony Hansa family (803),[3] a high-inclination family with more than a thousand known members.[4][21]: 23
It orbits the Sun in the intermediate asteroid belt at a distance of 2.5–2.9 AU once every 4 years and 5 months (1,621 days; semi-major axis of 2.7 AU). Its orbit has an eccentricity of 0.08 and an inclination of 21° with respect to the ecliptic.[2] The asteroid was first observed as A902 ED at Heidelberg Observatory in March 1902. The body's observation arc begins ten days after its official discovery observation at Heidelberg.[1]
In 2011, two modeled lightcurves using data from the Uppsala Asteroid Photometric Catalogue (UAPC) and from asteroidal occultation silhouettes gave a concurring period 7.87754 hours. The studies also determined a spin axis at (296.0°, 41.0°) and (294.0°, 41.0°) in ecliptic coordinates (λ, β), respectively.[8][15]
In 2003, stellar occultation measured a diameter of 59.2 kilometres and deduced an albedo of 0.218,[11] while the modelling of asteroid occultation silhouettes gave a diameter of 58 kilometres.[8] The asteroid has been observed in stellar occultations 8 times since 2003.[22]
The Collaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE data, that is, an albedo of 0.2266 and a diameter of 58.06 kilometers based on an absolute magnitude of 8.41.[9]
Naming
This minor planet was named in honor of the Iberian Kings, Alfonso X (1221–1284) and Alfonso XIII (1886–1941), King of Castile and Spain, respectively. The original citation from 1920, mentions, that the 13th century king inspired the field of astronomy in the Middle Ages, and, that the latter king was a great enthusiast of the scientific development in Spain. It also mentions that the King of Spain approved the naming of the asteroid (AN 211, 223).[20]
Notes
^ abHamanowa (2011) web: rotation period 7.883±0.002 hours with a brightness amplitude of
0.30 mag. Summary figures for (925) Alphonsina at the LCDB.
^ abHanslmeier (1980): rotation period for (925) Alphonsina of 7.92 hours with a brightness amplitude of 0.18 mag. Quality Code of 2. Summary figures at the LCDB.
^ abHergenrother, C. W.; Larson, S. M.; Spahr, T. B. (September 1996). "The Hansa Family: A New High-Inclination Asteroid Family". American Astronomical Society. 28: 1097. Bibcode:1996DPS....28.1007H.
^ abcMasiero, 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.
^ abcdPravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012). "Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations". Icarus. 221 (1): 365–387. Bibcode:2012Icar..221..365P. doi:10.1016/j.icarus.2012.07.026.
^ abcdUsui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; 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.
^ abcdMasiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; 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.
^ abHanus, J.; Durech, J.; Broz, M.; Warner, B. D.; Pilcher, F.; et al. (June 2011). "A study of asteroid pole-latitude distribution based on an extended set of shape models derived by the lightcurve inversion method". Astronomy and Astrophysics. 530: 16. arXiv:1104.4114. Bibcode:2011A&A...530A.134H. doi:10.1051/0004-6361/201116738.
^ abAlton, Kevin B. (July 2017). "CCD Lightcurves for Main-belt Asteriods [sic] 423 Diotima and 925 Alphonsina". The Minor Planet Bulletin. 44 (3): 188–189. Bibcode:2017MPBu...44..188A. ISSN1052-8091.