Discovered by A. Bohrmann Minor planet category main-belt · (inner) Discovered 24 February 1938 | Discovery date 24 February 1938 Alternative names 1938 DX1 · 1966 TF Observation arc 78.69 yr (28,743 days) Orbits Sun Asteroid group Asteroid belt | |
Discovery site Heidelberg-Königstuhl State Observatory Similar Asteroid belt, 1996 Adams, Sun | ||
1998 Titius, provisional designation 1938 DX1, is a metallic–carbonaceous asteroid from the inner regions of the asteroid belt, approximately 14 kilometers in diameter. It was discovered on 24 February 1938, by German astronomer Alfred Bohrmann at Heidelberg Observatory in southern Germany. On the same night, Titius was also observed at the Finnish Turku Observatory.
The asteroid orbits the Sun at a distance of 2.3–2.6 AU once every 3 years and 9 months (1,374 days). Its orbit has an eccentricity of 0.06 and an inclination of 8° with respect to the ecliptic. It stays in a 2:1 orbital resonance with the planet Mars. Titius' observation arc starts on the following night of its official discovery observation.
According to observations carried out by the Japanese Akari and NASA's Wide-field Infrared Survey Explorer (WISE) with its subsequent NEOWISE mission, Titius has an albedo between 0.093 and 0.126, and its diameter measures between 14.2 and 16.0 kilometers. The Collaborative Asteroid Lightcurve Link assumes a standard albedo of 0.20 and calculates a diameter of 10.8 kilometers, based on an absolute magnitude of 12.2.
Its spectral classification is that of a Xc-type asteroid in the SMASS taxonomy, a transitional spectral type between the two large main groups of metallic X-type and carbonaceous C-type asteroids. Both types are much darker than the stony S-type asteroids, which are also very common in the inner main-belt. In addition, Titius is also classified as a M-type asteroid by WISE.
A rotational light-curve, obtained from photometric observations made at the Californian Santana Observatory in March 2002, gave a rotation period of 7000613000000000000♠6.13±0.01 hours, during which its brightness amplitude varies by 6999300000000000000♠0.30±0.04 magnitude (U=3).
It is named after German astronomer Johann Daniel Titius (1729–1796), best known for formulating the Titius-Bode law, which states that each subsequent planet in the Solar System is roughly twice as far from the Sun than the previous one. He is also honored by the lunar crater Titius. Naming citation was published before November 1977 (M.P.C. 4237).