1527 Malmquista

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1527 Malmquista
1527Malmquista (Lightcurve Inversion).png
Lightcurve-based 3D-model of Malmquista
Discovery [1]
Discovered by Y. Väisälä
Discovery site Turku Obs.
Discovery date 18 October 1939
MPC designation (1527) Malmquista
Named after
Gunnar Malmquist
1939 UG · 1929 TG
1932 OB · 1972 TK
A909 TC
main-belt · Flora[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 87.47 yr (31,948 days)
Aphelion 2.6694 AU
Perihelion 1.7846 AU
2.2270 AU
Eccentricity 0.1987
3.32 yr (1,214 days)
0° 17m 47.76s / day
Inclination 5.1939°
Physical characteristics
Dimensions 9.55±0.49 km[4]
10.040±0.134 km[5]
10.338±0.071 km[6]
10.80 km (calculated)[3]
14.044±0.0244 h[7]
14.0591 h[8]
14.077±0.004 h[9]
0.24 (assumed)[3]
12.0[1][3][4] · 12.2[6] · 12.481±0.002 (S)[7]

1527 Malmquista, provisional designation 1939 UG, is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 10 kilometers in diameter.

It was discovered on 18 October 1939, by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland.[10] It was named for the Swedish astronomer Gunnar Malmquist.[2]

Orbit and classification[edit]

Malmquista is a member of the Flora family, one of the largest families of stony asteroids in the main belt. It orbits the Sun in the inner main-belt at a distance of 1.8–2.7 AU once every 3 years and 4 months (1,214 days). Its orbit has an eccentricity of 0.20 and an inclination of 5° with respect to the ecliptic.[1] In 1909, it was first observed at Heidelberg Observatory as A909 TC. The body's observation arc begins at Lowell Observatory in 1929, when it was identified as 1929 TG, 10 years prior to its official discovery observation at Turku.[10]

Physical characteristics[edit]

Rotation period[edit]

In September 2002, a first rotational lightcurve of Malmquista was obtained from photometric observations by Stephen Brincat at Flarestar Observatory on the island of Malta. Lightcurve analysis gave a well-defined rotation period of 14.077 hours with a brightness variation of 0.60 magnitude (U=3).[9] In September 2012, observations at the Palomar Transient Factory, California, gave a period of 14.044 hours and an amplitude of 0.42 magnitude (U=2).[7]

Spin axis[edit]

In 2013, an international study modeled a lightcurve with a period of 14.0591 hours and found a spin axis of (5.0°, 80.0°) in ecliptic coordinates (λ, β) (U=n.a.).[8]

Diameter and albedo[edit]

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Malmquista measures between 9.55 and 10.338 kilometers in diameter and its surface has an albedo between 0.220 and 0.307.[4][5][6] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, a S-type asteroid and the family's largest member and namesake – and calculates a diameter of 10.80 kilometers with an absolute magnitude of 12.0.[3]


This minor planet was named after Swedish astronomer Gunnar Malmquist (1893–1982), director of the Uppsala Astronomical Observatory in Sweden.[2] The official naming citation was published by the Minor Planet Center before November 1977 (M.P.C. 1350).[11]


  1. ^ a b c d "JPL Small-Body Database Browser: 1527 Malmquista (1939 UG)" (2017-03-29 last obs.). Jet Propulsion Laboratory. Retrieved 13 June 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1527) Malmquista. Springer Berlin Heidelberg. p. 121. ISBN 978-3-540-00238-3. Retrieved 7 April 2017.
  3. ^ a b c d e f "LCDB Data for (1527) Malmquista". Asteroid Lightcurve Database (LCDB). Retrieved 7 April 2017.
  4. ^ 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 7 April 2017.
  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 7 April 2017.
  6. ^ 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" (PDF). The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 7 April 2017.
  7. ^ a b c Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. Retrieved 7 April 2017.
  8. ^ a b Hanus, J.; Broz, M.; Durech, J.; Warner, B. D.; Brinsfield, J.; Durkee, R.; et al. (November 2013). "An anisotropic distribution of spin vectors in asteroid families". Astronomy and Astrophysics. 559: 19. arXiv:1309.4296. Bibcode:2013A&A...559A.134H. doi:10.1051/0004-6361/201321993. Retrieved 7 April 2017.
  9. ^ a b Brincat, Stephen M. (December 2002). "Rotation period and lightcurve of asteroid 1527 Malmquista". The Minor Planet Bulletin. 30 (2): 19. Bibcode:2003MPBu...30...19B. ISSN 1052-8091. Retrieved 7 April 2017.
  10. ^ a b "1527 Malmquista (1939 UG)". Minor Planet Center. Retrieved 7 April 2017.
  11. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 7 April 2017.

External links[edit]