August 29, 2013: Asteroid (11438) Zeldovich discovered 40 years ago


   Forty years ago, on August 29th, 1973 Tamara Mikhailovna Smirnova at Crimean Astrophysical Observatory has found a new moving object of 15th magnitude in the constellation of Pisces which was given a preliminary designation 1973 QR1. Later on this minor planet was assigned the permanent number (11438) and the name Zeldovich. Asteroid (11438) has quite an elongated orbit with a period of 3.25 yr and eccentricity 0.19 (twice that of Mars). Its distance from the Sun varies in the range of 1.77-2.62 astronomical units, this is why the visible magnitude changes widely. Just like Mars, asteroid Zeldovich has "great" oppositions near the perihelion of orbit when its brightness reaches the maximum (about 15m) and less favorable (aphelion) ones with the 17th magnitude. On September 11th, 2012 asteroid (11438) Zeldovich had an encounter with Earth to 0.864 AU, reaching one of its best recent oppositions on September 20th. MASTER-Kislovodsk robotic telescope has caught minor planet (11438) in course of routine sky survey on October 10th, 2012 at magnitude 15.7. Animation of three images by MASTER is shown in the picture.

  Currently asteroid Zeldovich is near the Sun and can not be observed. It will pass the opposition on 2014 February 1st, one month before the Yakov Borisovich' 100th anniversary. Asteroid will be located in Cancer constellation at the distance of 1.63 AU from Earth and 2.62 AU from the Sun (near the aphelion of its orbit), with the magnitude being 17.0m. Telescopes of MASTER network will definitely observe asteroid (11438) Zeldovich in early 2014.