1409 Isko

1409 Isko, provisional designation, is a carbonaceous background asteroid from the central regions of the asteroid belt, approximately 35 kilometers in diameter. It was discovered on 8 January 1937, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southwest Germany. The asteroid was named after Ise Koch, wife of astronomer Fritz Kubach.

Orbit and classification
Isko is a non-family asteroid of the main belt's background population. It orbits the Sun in the central asteroid belt at a distance of 2.5–2.8 AU once every 4 years and 5 months (1,599 days). Its orbit has an eccentricity of 0.06 and an inclination of 7° with respect to the ecliptic.

The body's observation arc begins with its first identification as at Heidelberg in October 1900, more than 36 years prior to its official discovery observation.

Physical characteristics
Isko has been characterized as a carbonaceous C-type asteroid by Pan-STARRS photometric survey.

Rotation period
In December 2001, a rotational lightcurve of Isko was obtained from photometric observations by French amateur astronomers Laurent Bernasconi and René Roy. Lightcurve analysis gave a rotation period of 11.6426 hours with a brightness amplitude of 0.20 magnitude (U=2).

Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Isko measures between 34.62 and 38.46 kilometers in diameter and its surface has an albedo between 0.032 and 0.0805.

The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0514 and a diameter of 35.34 kilometers based on an absolute magnitude of 11.1.

Naming
This minor planet was named after Ise Koch, wife of German astronomer Fritz Kubach (1912–1945)(de) The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 127).