1542 Schalén

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1542 Schalén
Discovery [1]
Discovered by Y. Väisälä
Discovery site Turku Obs.
Discovery date 26 August 1941
Designations
MPC designation (1542) Schalén
Named after
Karl Schalén (astronomer)[2]
1941 QE · 1927 BH
1936 UL · 1940 LP
1976 CA · A898 VD
A924 NA
main-belt · Themis[3]
Orbital characteristics[1]
Epoch 16 February 2017 (JD 2457800.5)
Uncertainty parameter 0
Observation arc 117.73 yr (43,001 days)
Aphelion 3.4510 AU
Perihelion 2.7343 AU
3.0926 AU
Eccentricity 0.1159
5.44 yr (1,987 days)
284.94°
0° 10m 52.32s / day
Inclination 2.7662°
211.66°
Physical characteristics
Dimensions 42.374±0.273 km[4]
45.05 km (derived)[3]
48.998±0.480 km[5]
7.516±0.002 h[6]
0.0501 (derived)[3]
0.0509±0.0105[5]
0.068±0.003[4]
SMASS = D[1] · D[3]
10.4[5] · 10.6[1][3]

1542 Schalén, provisional designation 1941 QE, is a rare-type Themistian asteroid from the outer region of the asteroid belt, approximately 45 kilometers in diameter.

It was discovered on 26 August 1941, by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland,[7] it was later named after Swedish astronomer Karl Schalén.[2]

Orbit and classification[edit]

Schalén is a member of the Themis family, a dynamical family of outer-belt asteroids with nearly coplanar ecliptical orbits.[3] It orbits the Sun at a distance of 2.7–3.5 AU once every 5 years and 5 months (1,987 days). Its orbit has an eccentricity of 0.12 and an inclination of 3° with respect to the ecliptic.[1] It was first identified as A898 VD at Heidelberg Observatory in 1898, extending the body's observation arc by 43 years prior to its official discovery observation at Turku.[7]

Physical characteristics[edit]

Schalén has a rare D-type spectrum, mostly found among Hildian asteroids and Jupiter trojans.[8] Bodies with a D-type spectra are thought to have originated in the Kuiper belt.

Diameter and albedo[edit]

According to the 2014-result of the survey carried by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Schalén measures 42.374 kilometers in diameter and its surface has an albedo of 0.068,[4] while the Collaborative Asteroid Lightcurve Link derives an albedo of 0.0509 and a diameter of 45.05 kilometers with an absolute magnitude of 10.6.[3]

Rotation period[edit]

In November 2012, a rotational lightcurve of Schalén was obtained from photometric observations by astronomers at the Purple Mountain Observatory in collaboration with observatories in the United States. Lightcurve analysis gave a well-defined rotation period of 7.516 hours with a brightness variation of 0.49 magnitude (U=3).[6]

Naming[edit]

This minor planet was named in honour of Swedish astronomer Karl Adam Wilhelm Schalén (1902–1993), who was a director of the Swedish Lund Observatory.[2] Naming citation was published before November 1977 (M.P.C. 3930).[9]

References[edit]

  1. ^ a b c d e "JPL Small-Body Database Browser: 1542 Schalen (1941 QE)" (2016-08-08 last obs.). Jet Propulsion Laboratory. Retrieved 30 December 2016. 
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1542) Schalén. Springer Berlin Heidelberg. p. 122. ISBN 978-3-540-00238-3. Retrieved 30 December 2016. 
  3. ^ a b c d e f g "LCDB Data for (1542) Schalén". Asteroid Lightcurve Database (LCDB). Retrieved 30 December 2016. 
  4. ^ a b c 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:1406.6645Freely accessible. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. Retrieved 30 December 2016. 
  5. ^ a b c Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results" (PDF). The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 30 December 2016. 
  6. ^ a b Li, Bin; Zhao, Haibin; Han, Xianming L.; Klinglesmith, Daniel A., III; Hanowell, Jesse (April 2013). "Photometric Observation of 1542 Schalen". The Minor Planet Bulletin. 40 (2): 68–69. Bibcode:2013MPBu...40...68L. ISSN 1052-8091. Retrieved 30 December 2016. 
  7. ^ a b "1542 Schalen (1941 QE)". Minor Planet Center. Retrieved 30 December 2016. 
  8. ^ "JPL Small-Body Database Search Engine: [ spec. type = D (Tholen) or spec. type = D (SMASSII) ]". JPL Solar System Dynamics. Retrieved 30 December 2016. 
  9. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 30 December 2016. 

External links[edit]