Discovery date 16 October 1977 Alternative names 2114 T-3 · 1993 VH2 Orbital period 1,888 days Orbits Sun Discovery site Palomar Observatory | MPC designation 9826 Ehrenfreund Minor planet category main-belt · Eos Discovered 16 October 1977 Asteroid family Eos family Asteroid group Asteroid belt | |
Discovered by C. J. van Houten
I. van Houten
T. Gehrels Named after Pascale Ehrenfreund
(astrophysicist) Discoverers Tom Gehrels, Cornelis Johannes van Houten, Ingrid van Houten-Groeneveld | ||
9826 Ehrenfreund, provisional designation 2114 T-3, is a stony asteroid from the outer region of the asteroid belt, approximately 7 kilometers in diameter. It was discovered on 16 October 1977, by Dutch astronomer couple Ingrid and Cornelis van Houten at Leiden, on photographic plates taken by Dutch–American astronomer Tom Gehrels at the U.S. Palomar Observatory in California.
The S-type asteroid is a member of the Eos family, an orbital group of more than 4,000 asteroids, which are well known for mostly being of stony composition. It orbits the Sun at a distance of 2.7–3.3 AU once every 5 years and 2 months (1,894 days). Its orbit has an eccentricity of 0.09 and an inclination of 9° with respect to the ecliptic. The first used observation was taken at the discovering observatory on 7 October 1977, extending the asteroid's observation arc by just 9 days prior to its discovery.
A rotational light-curve for this asteroid was obtained from photometric observations taken at the U.S. Palomar Transient Factory in August 2013. It gave a rotation period of 7000374840000000000♠3.7484±0.0013 hours with a brightness variation of 0.37 in magnitude (U=2).
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, the asteroid measures 8.4 kilometers in diameter and its surface has an albedo of 0.19, while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.14 – derived from the family's largest member and namesake, 221 Eos – and calculates a diameter of 6.9 kilometers. Since 221 Eos, the parent of a collisional group is classified as a K-type asteroid on the SMASS taxonomy scheme, this may also apply for 9826 Ehrenfreund.
The survey designation T-3 stands for the last of three Palomar–Leiden Trojan surveys, named after the fruitful collaboration of the Palomar and Leiden Observatory in the 1960s and 1970s. Gehrels used Palomar's Samuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped the photographic plates to Ingrid and Cornelis van Houten at Leiden Observatory where astrometry was carried out. The trio are credited with the discovery of several thousand minor planets.
The minor planet was named in honour of Austrian female astrophysicist and biochemist, Pascale Ehrenfreund (b. 1960), who has analyzed dust particles and circumstellar organic molecules on a number of space missions. Naming citation was published on 11 November 2000 (M.P.C. 41570). Ehrenfreund has been the lead investigator at NASA Astrobiology Institute and was elected CEO of the German Aerospace Center in 2015, the first woman to lead a major research facility in Germany.