981 Martina
981 Martina is a carbonaceous Themistian asteroid from the outer regions of the asteroid belt, approximately in diameter. It was discovered on 23 September 1917, by Russian astronomer Sergey Belyavsky at the Simeiz Observatory on the Crimean peninsula. The C/B-type asteroid has a rotation period of 11.3 hours. It was named after French historian and revolutionary Henri Martin.
Orbit and classification
Martina is a core member of the Themis family, a very large family of carbonaceous asteroids, named after 24 Themis. It orbits the Sun in the outer asteroid belt at a distance of 2.5–3.7 AU once every 5 years and 5 months. Its orbit has an eccentricity of 0.20 and an inclination of 2° with respect to the ecliptic. The body's observation arc begins with its first observation as at Lowell Observatory in August 1906, more than 11 years prior to its official discovery observation at Crimea–Simeis.Naming
This minor planet was named after French historian and revolutionary politician, Henri Martin. The was mentioned in The Names of the Minor Planets by Paul Herget in 1955.Physical characteristics
In the SDSS-based taxonomy, Martina is a carbonaceous C-type asteroid,while in the classical Tholen classification, it has been classified as a CFU: asteroid, closest to a C-type and somewhat similar to an F-type, though with an unusual and noisy spectra. In both the Tholen- and SMASS-like taxonomy of the Small Solar System Objects Spectroscopic Survey, Martina is a B-type asteroid, a "brighter" variant of the more common C-type. Members of the Themis family are typically classified as C-types with an albedo of 0.07, a value notably lower than for this asteroid at 0.10–0.13 .