Discovered by H. van Gent MPC designation 1693 Hertzsprung Discovered 5 May 1935 Orbits Sun Discovery site Union Observatory | Discovery date 5 May 1935 Minor planet category main-belt · (middle) Absolute magnitude 10.97 Discoverer Hendrik van Gent Asteroid group Asteroid belt | |
Named after Ejnar Hertzsprung
(chemist, astronomer) Alternative names 1935 LA · 1930 HG
1944 HA · 1950 VM People also search for 1702 Kalahari, 1627 Ivar, Sun | ||
1693 Hertzsprung, provisional designation 1935 LA, is a carbonaceous asteroid from the middle region of the asteroid belt, approximately 39 kilometers in diameter. It was discovered by Dutch astronomer Hendrik van Gent at the Leiden Southern Station, annex to the Johannesburg Observatory in South Africa on 5 May 1935.
The asteroid orbits the Sun at a distance of 2.0–3.6 AU once every 4 years and 8 months (1,708 days). Its orbit has an eccentricity of 0.27 and an inclination of 12° with respect to the ecliptic. The asteroid was already observed prior to its discovery at Crimea-Simeis in 1930. However, these precoveries were not used to extend its observation arc.
A rotational light-curve was obtained from photometric observations made with the ESO 1-metre telescope at La Silla in August 1987. The light-curve gave it a well-defined rotation period of 7000882499999999999♠8.825 hours with a brightness amplitude of 0.45 in magnitude (U=3).
According to the space-based surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, the asteroid measures between 35.3 and 40.4 kilometers in diameter and its surface has an albedo in the range of 0.033 to 0.059. The Collaborative Asteroid Lightcurve Link agrees with the results obtained by IRAS, that is an albedo of 0.048 and a diameter of 38.7 kilometers. While the dark C-type asteroid is classified as a rare CBU-subtype on the Tholen taxonomic scheme, the NEOWISE mission groups the body to the rare and reddish P-type asteroids.
The minor planet was named in memory of Danish chemist and astronomer Ejnar Hertzsprung (1873–1967), best known for the famous Hertzsprung–Russell diagram, a spectral classification system for stars he developed jointly with Russel, after whom the asteroid 1762 Russell was named. From 1934 to 1945, Hertzsprung was the head of the Leiden Observatory in the Netherlands. As a prominent expert in photometry, he initiated a survey of variable stars in the Southern Milky Way at the Leiden Southern Station. A number of asteroids and comets were also discovered during the course of this survey. The asteroid's name was suggested by the staff at Leiden Observatory. Naming citation was published before November 1977 (M.P.C. 2822).