Asteroid 2002 NY40


In August 2002, the asteroid 2002 NY40 came close to the Earth and was an easy target for telescopes of almost any size. On 16.8.2002, it had a brightness of ca. 11 mag and moved rapidly through the constellation of Sagitta.

A sequence of images was shot and stacked, showing the movement of the asteroid with respect to the background stars.
14 images were taken from 23:00 to 23:26, in 2-minute intervals. Exposure time for each individual image was 4 seconds. Each "step" of the asteroid is ca. 45 arcseconds wide.
C11 (3050 mm f.l.), CCD ST8, 4 sek exposure time; FOV ca. 15x10 arcmin.

On 17.8.2002, the asteroid was brighter (ca. 9.5 mag) and even closer to Earth. We planned, in cooperation with the Pleiade Observatory Verona, to measure its parallax and to determine its distance.

Thus, images of NY40 were taken from Verona and Munich, at exactly the same time. The images show the asteroid at slightly different apparent positions from which the distance of the asteroid can be calculated.

When comparing the images taken from Munich and Verona, we found a difference in position of NY40 in relation to the background stars of 62 arcseconds (this is an enormous parallax angle compared with the usual values for asteroids). From such parallax angle, and knowing the distance of the observation sites (292.6 km), a distance of ca. 970000 kms was found for the asteroid.

The composite image below (stacked images from Munich and Verona) shows the asteroid "jumping" in front of the background stars due to the different apparent positions when observed from the different locations on Earth.