1719 Jens

1719 Jens (prov. designation: ) is a background asteroid from the central region of the asteroid belt, approximately 19 kilometers in diameter. It was discovered on 17 February 1950, by German astronomer Karl Reinmuth at Heidelberg Observatory in southern Germany. It was named after a grandson of the discoverer.

Orbit and classification


Jens orbits the Sun in the central main-belt at a distance of 2.1–3.2 AU once every 4 years and 4 months (1,581 days). Its orbit has an eccentricity of 0.22 and an inclination of 14° with respect to the ecliptic. First identified as at Simeiz Observatory in 1922, Jens first used observation was taken at Turku in 1948, extending the body's observation arc by 2 years prior to its official discovery observation.

In 2010, Jens was passing in front of the Tadpole Nebula (see image obtained by WISE).

Lightcurves
In September 2000, American astronomer Brian Warner obtained two rotational lightcurves, giving a rotation period of 5.867 and 5.87 hours with a brightness variation of 0.50 and 0.55 magnitude, respectively (U=3/3).

In February 2006, photometric observations by French amateur astronomer Laurent Bernasconi gave a concurring period of 5.873 hours with an amplitude of 0.55 magnitude (U=3). This well-defined period was further confirmed by a modeled light-curve using data from the Lowell Photometric Database, giving a period of 5.87016 hours (U=n.a.).

Spectral type
It is classified as S- and C-type asteroid by the LCDB and Pan-STARRS, respectively.

Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite IRAS and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Jens measures between 18.93 and 21.61 kilometers in diameter and its surface has an albedo between 0.085 and 0.149. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.1048 and calculates a diameter of 18.76 kilometers based on an absolute magnitude of 11.7.

Naming
This minor planet was named by the discoverer for his grandson. Karl Reinmuth also named the consecutively numbered asteroid, 1720 Niels, after one of his grandsons. The official was published by the Minor Planet Center on 20 February 1976 (M.P.C. 3933).