Subaru Telescope photographed the comet 103P/Hartley
approaching to the Earth
Scientists used Suprime-Cam at Subaru Telescope to catch the comet 103P/Hartley after long shut down of the telescope. This summer Subaru Telescope underwent primary mirror recoating, modification to its top, overhauling of many actuators, and so on. Since the distance to the comet from the Earth is small and the apparent movement of the comet on the sky is large, non-sidereal tracking was used during this observation based on the orbital parameters of the comet. This image is composed from the dataset of three different filters; g'-band (480nm), r'-band (620nm), and z'-band (900nm), and color coding is allotted for blue, green, and red, respectively. Since the comet was moving from the lower right to the upper left compared with the background stars, each background star appears as triple points with three colors along the direction of the comet movement.
Shouts of joy arose from the observers as well as the night crews on site when the telescope slew to the calculated position and the comet's tail appeared on a monitor. The observation crew is looking forward to obtaining even more striking results with an innovative instrument that will be installed on Subaru Telescope in near future. What is that instrument? Stay tuned.
Information on the picture obtained with Subaru Telescope is as follows.
Date of Observations: September 17, 2010 (HST)
Exposure Time: 20 seconds for g'-band, 10 seconds for r'- and z'-bands
Observers: Mr. Yousuke Utsumi (GUAS), Dr. Daigo Tomono, Dr. Fumiaki Nakata (Subaru Telescope)
Labels: comet 103P/Hartley, Subaru Telescope