7387 Malbil

7387 Malbil
007387-asteroid shape model (7387) Malbil.png
Shape model of Malbil from its lightcurve
Discovery [1]
Discovered byE. Bowell
Discovery siteAnderson Mesa Stn.
Discovery date30 January 1982
(7387) Malbil
Named after
Malcolm Bilson
(American pianist)[2]
1982 BS1
Orbital characteristics[3]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc35.44 yr (12,946 days)
Aphelion2.8283 AU
Perihelion2.0728 AU
2.4506 AU
3.84 yr (1,401 days)
0° 15m 24.84s / day
Physical characteristics
Mean diameter
6.3 km (est. at 0.20)[7]
7.5498 h[8]
  • (253°, −74°) (λ11)[8]
  • (127.0°, −69.0°) (λ22)[8]

7387 Malbil (prov. designation: 1982 BS1) is an elongated background asteroid from the inner regions of the asteroid belt. It was discovered on 30 January 1982, by American astronomer Edward Bowell at Lowell's Anderson Mesa Station in Arizona, United States.[1] The asteroid has a rotation period of 7.5 hours and measures approximately 6 kilometers (4 miles) in diameter. It is named for American pianist Malcolm Bilson.[2]

Classification and orbit[]

Malbil is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.[4][5] It orbits the Sun in the inner main-belt at a distance of 2.1–2.8 AU once every 3 years and 10 months (1,401 days). Its orbit has an eccentricity of 0.15 and an inclination of 7° with respect to the ecliptic.[3] The body's observation arc begins with its first used observation at the discovering observatory in 1986, or 4 years after its official discovery observation.[1]


This minor planet was named after American fortepianist and musicologist Malcolm Bilson (born 1935), who gave a recital at the "Asteroids, Comets, Meteors" conference at Cornell University in New York.[2] The approved naming citation was published by the Minor Planet Center on 28 July 1999 (M.P.C. 35485).[9]

Physical characteristics[]

As of 2020, Malbil's effective size, its composition and albedo remain unknown.[3][10] Data from photometric observation gave a modeled sidereal rotation period of 7.5498 hours and two spin axes at (253°, −74°) and (127.0°, −69.0°) in ecliptic coordinates (λ, β). The modeling suggests that the asteroid is rather elongated in shape.[8]

Based on a magnitude-to-diameter conversion, its generic diameter is between 5 and 12 kilometer for an absolute magnitude of 13.4, and an assumed albedo in the range of 0.05 to 0.25.[7] Since asteroids in the inner main-belt are typically of stony rather than carbonaceous composition, with albedos of 0.20 or higher, Malbil's diameter can be estimate to measure around 6.3 kilometers, as the higher its albedo (reflectivity), the lower the body's diameter at a constant absolute magnitude (brightness).[7]


  1. ^ a b c d "7387 Malbil (1982 BS1)". Minor Planet Center. Retrieved 12 March 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(7387) Malbil". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 594. doi:10.1007/978-3-540-29925-7_6462. ISBN 978-3-540-00238-3.
  3. ^ a b c d e "JPL Small-Body Database Browser: 7387 Malbil (1982 BS1)" (2017-07-05 last obs.). Jet Propulsion Laboratory. Retrieved 5 September 2017.
  4. ^ a b "Asteroid 7387 Malbil – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 23 March 2020.
  5. ^ a b "Asteroid 7387 Malbil". Small Bodies Data Ferret. Retrieved 23 March 2020.
  6. ^ Zappalà, V.; Bendjoya, Ph.; Cellino, A.; Farinella, P.; Froeschle, C. (1997). "Asteroid Dynamical Families". NASA Planetary Data System: EAR-A-5-DDR-FAMILY-V4.1. Retrieved 15 March 2020.} (PDS main page)
  7. ^ a b c "Asteroid Size Estimator". CNEOS/JPL. Retrieved 5 September 2017.
  8. ^ a b c d Hanuš, J.; Ďurech, J.; Oszkiewicz, D. A.; Behrend, R.; Carry, B.; Delbo, M.; et al. (February 2016). "New and updated convex shape models of asteroids based on optical data from a large collaboration network". Astronomy and Astrophysics. 586: A108. arXiv:1510.07422. Bibcode:2016A&A...586A.108H. doi:10.1051/0004-6361/201527441. ISSN 0004-6361. (DAMIT–online)
  9. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 12 March 2017.
  10. ^ "LCDB Data for (7387) Malbil". Asteroid Lightcurve Database (LCDB). Retrieved 12 March 2017.

External links[]