(182) Elsa

182 Elsa
182Elsa (Lightcurve Inversion).png
Lightcurve-based 3D-model of Elsa
Discovered byJ. Palisa
Discovery siteAustrian Naval Obs.
Discovery date7 February 1878
(182) Elsa
Named after
uncertain; various suggestions[2]
1948 XS · 1950 HY
main-belt[1][3] · (inner)
Massalia[4] · background[5]
Orbital characteristics[3]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 0
Observation arc114.68 yr (41,886 d)
Aphelion2.8656 AU
Perihelion1.9657 AU
2.4156 AU
3.75 yr (1,371 d)
0° 15m 45s / day
Physical characteristics
Mean diameter
43.68±4.1 km[6]
44.000±4.279 km[7]
44±0.1 km[8]
45.15±0.62 km[9]
45.72±7.82 km[10]
80.088±0.002 h[11]
Tholen = S[3]
SMASS = S[3][12]
B–V = 0.862[3]
U–B = 0.425[3]

Elsa (/ˈɛlzə/; minor planet designation: 182 Elsa) is a Massalia or background asteroid from the inner regions of the asteroid belt, approximately 44 kilometers (27 miles) in diameter. It was discovered on 7 February 1878, by Austrian astronomer Johann Palisa at the Austrian Naval Observatory in today's Croatia.[1] The S-type asteroid has a very long rotation period of 80 hours and likely an elongated shape.[12] The origin of its name is uncertain.[2]

Orbit and classification[]

Elsa is a member of the Massalia family (404),[4] a very large inner belt asteroid family consisting of stony asteroids.[15] In a different HCM-study, however, it has been found to be a non-family asteroid from the main belt's background population.[5]

It orbits the Sun in the inner main-belt at a distance of 2.0–2.9 AU once every 3 years and 9 months (1,371 days; semi-major axis of 2.42 AU). Its orbit has an eccentricity of 0.19 and an inclination of 2° with respect to the ecliptic.[3]


The origin of this minor planet's name is uncertain.[2] Originally, the asteroid was named "Elsbeth" – the Austrian variant of "Elisabeth" – and only later changed into a more lyrical "Elsa" with the consent of the discoverer, Johann Palisa.[2] It may have been named after the character in the legend of Lohengrin perpetuated by Richard Wagner's opera of the same name.[citation needed] It may also refer to the Empress Elisabeth of Austria (1854–1898), or to a relative of Admiral Bourgignon, who requested the naming, as he was the military superior of the discoverer at the Naval Observatory at Pola. Finally, the name "Elsbeth" just might have been chosen generically as it is one of the most common feminine Christian names.[2]

Physical characteristics[]

Elsa has been characterized as a common, stony S-type asteroid in both the Tholen and SMASS classification.[3]

Rotation period[]

The asteroid is a relatively slow rotator.[12] In 1980, its rotation period was estimated to be about 3.3 Earth days.[13] In 2008, a collaborative effort from three different sites under the lead of Frederick Pilcher was used to build a complete lightcurve for the asteroid, which showed a period of 80.088±0.002 hours with a brightness variation of 0.30±0.03 in magnitude. A possible companion has been proposed to explain the slow rotation.[11] Other period determinations gave similar results between 80.166 and 80.23 hours with an outlier by the Palomar Transient Factory.[16][17][18][a]

Elsa has very amplified lightcurve indicating an elongated or irregular body. It was one of five minor planets included in the 1993 study, Transition Comets -- UV Search for OH Emissions in Asteroids, which was research involving amateur astronomers who were permitted to make use of the Hubble Space Telescope.

Diameter and albedo[]

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Elsa measures between 36 and 45.72 kilometers in diameter and its surface has an albedo between 0.196 and 0.2106.[19][20][6][7][9][10]

During 2002, Elsa was also observed by radar from the Arecibo Observatory. The return signal matched an effective diameter of 44±10 km.[8]


  1. ^ See summary figures for (182) Elsa at the LCDB.


  1. ^ a b c d "182 Elsa". Minor Planet Center. Retrieved 29 May 2018.
  2. ^ a b c d e Schmadel, Lutz D. (2007). "(182) Elsa". Dictionary of Minor Planet Names – (182) Elsa. Springer Berlin Heidelberg. p. 31. doi:10.1007/978-3-540-29925-7_183. ISBN 978-3-540-29925-7.
  3. ^ a b c d e f g h i "JPL Small-Body Database Browser: 182 Elsa" (2018-09-18 last obs.). Jet Propulsion Laboratory. Retrieved 13 February 2019.
  4. ^ a b "Asteroid 182 Elsa". Small Bodies Data Ferret. Retrieved 29 May 2018.
  5. ^ a b "Asteroid (182) Elsa". AstDyS-2, Asteroids – Dynamic Site. Retrieved 25 May 2018.
  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 – IRAS-A-FPA-3-RDR-IMPS-V6.0: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T. Retrieved 13 February 2019.
  7. ^ 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. (catalog)
  8. ^ a b Magri, Christopher; Nolan, Michael C.; Ostro, Steven J.; Giorgini, Jon D. (January 2007). "A radar survey of main-belt asteroids: Arecibo observations of 55 objects during 1999 2003" (PDF). Icarus. 186 (1): 126–151. Bibcode:2007Icar..186..126M. doi:10.1016/j.icarus.2006.08.018. Retrieved 29 May 2018.
  9. ^ 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. Retrieved 17 October 2019. (online, AcuA catalog p. 153)
  10. ^ a b c d 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. arXiv:1606.08923. Bibcode:2016AJ....152...63N. doi:10.3847/0004-6256/152/3/63.
  11. ^ a b Pilcher, Frederick; Benishek, Vladimir; Krajewski, Richard (April 2009). "Period Determination for 182 Elsa: A Collaboration Triumph". The Minor Planet Bulletin. 36 (2): 40. Bibcode:2009MPBu...36...40P. ISSN 1052-8091.
  12. ^ a b c d "LCDB Data for (182) Elsa". Asteroid Lightcurve Database (LCDB). Retrieved 29 May 2018.
  13. ^ a b Harris, A. W.; Young, J. W. (July 1980). "Asteroid rotation. III - 1978 observations". Icarus. 43 (1): 20–32. Bibcode:1980Icar...43...20H. doi:10.1016/0019-1035(80)90084-6.
  14. ^ Harris, A. W.; Young, J. W.; Dockweiler, Thor; Gibson, J.; Poutanen, M.; Bowell, E. (January 1992). "Asteroid lightcurve observations from 1981". Icarus. 95 (1): 115–147. Bibcode:1992Icar...95..115H. doi:10.1016/0019-1035(92)90195-D. ISSN 0019-1035.
  15. ^ Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). Identification and Dynamical Properties of Asteroid Families. Asteroids IV. pp. 297–321. arXiv:1502.01628. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131.
  16. ^ Chang, Chan-Kao; Ip, Wing-Huen; Lin, Hsing-Wen; Cheng, Yu-Chi; Ngeow, Chow-Choong; Yang, Ting-Chang; et al. (June 2014). "313 New Asteroid Rotation Periods from Palomar Transient Factory Observations". The Astrophysical Journal. 788 (1): 21. arXiv:1405.1144. Bibcode:2014ApJ...788...17C. doi:10.1088/0004-637X/788/1/17.
  17. ^ Durech, J.; Kaasalainen, M.; Warner, B. D.; Fauerbach, M.; Marks, S. A.; Fauvaud, S.; et al. (January 2009). "Asteroid models from combined sparse and dense photometric data" (PDF). Astronomy and Astrophysics. 493 (1): 291–297. Bibcode:2009A&A...493..291D. doi:10.1051/0004-6361:200810393. Retrieved 24 August 2017.
  18. ^ Gandolfi, D.; Cigna, M.; Fulvio, D.; Blanco, C. (January 2009). "CCD and photon-counting photometric observations of asteroids carried out at Padova and Catania observatories". Planetary and Space Science. 57 (1): 1–9. arXiv:0810.1560. Bibcode:2009P&SS...57....1G. doi:10.1016/j.pss.2008.09.014.
  19. ^ Marchis, F.; Kaasalainen, M.; Hom, E. F. Y.; Berthier, J.; Enriquez, J.; Hestroffer, D.; et al. (November 2006). "Shape, size and multiplicity of main-belt asteroids. I. Keck Adaptive Optics survey". Icarus. 185 (1): 39–63. Bibcode:2006Icar..185...39M. doi:10.1016/j.icarus.2006.06.001. PMC 2600456. PMID 19081813.
  20. ^ 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.

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