1449 Virtanen, provisional designation 1938 DO, is a stony Florian
asteroid from the inner regions of the
asteroid belt, approximately 9.2 kilometers in diameter. It was discovered on 20 February 1938, by Finnish astronomer
Yrjö Väisälä at
Turku Observatory in Southwest Finland,[15] and named for Finnish biochemist
Artturi Virtanen.[2]
Description
Virtanen is a member of the
Flora family, one of the largest collisional populations of stony asteroids in the main-belt. It orbits the Sun in the
inner main-belt at a distance of 1.9–2.5
AU once every 3 years and 4 months (1,210 days). Its orbit has an
eccentricity of 0.14 and an
inclination of 7
° with respect to the
ecliptic.[1] In 1928, Virtanen was first identified as 1928 DC at
Heidelberg, extending the body's
observation arc by 10 years prior to its official discovery at Turku.[15]
Virtanen's first rotational
lightcurve was obtained by astronomers
Pierre Antonini and
Silvano Casulli in May 2007, followed by Australian astronomer Julian Oey at Leura (E17) and Kingsgrove Observatory (E19) in June 2008. The lightcurves gave a
rotation period of approximately 30.5 hours with a brightness variation of 0.6
magnitude (U=2-/3-/3-).[9][10]
Additional periods were obtained from photometric observation in the R and S-band at the
Palomar Transient Factory (U=2/2/2),[8][13] and from modeled data using the Lowell photometric database and other data sources, which also gave two spin axis of (307.0°, 58.0°) and (89.0°, 61.0°) in
ecliptic coordinates, respectively (U=n.a.).[11][12]
Diameter and albedo
According to the survey carried out by NASA's
Wide-field Infrared Survey Explorer with its subsequent
NEOWISE mission, Virtanen measures between 9.15 and 9.947 kilometers in diameter, and its surface has an
albedo between 0.285 and 0.36.[4][5][6][7]
The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from
8 Flora, the largest member and namesake of its family – and calculates a diameter of 10.31 kilometers with an
absolute magnitude of 12.1.[3]
^
abHanus, J.; Durech, 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: 24.
arXiv:1510.07422.
Bibcode:
2016A&A...586A.108H.
doi:
10.1051/0004-6361/201527441.
S2CID119112278.