DES Observational Technique

BASIC STRATEGY

On a single exposure of a few minutes duration, a typical KBO appears as a faint point source. They can be distinguished from background stars by detecting their apparent motion relative to the distant scene of stars and galaxies. This motion which is largely a reflex motion due to the Earth's orbital motion and typically has a rate between 1.5 and 3 arcsec per hour for objects at distances between 30 and 50 AU. Ordinarily, KBOs have apparent magnitudes fainter than R=20 with the number per square degree increasing rapidly as the magnitude increases.

In our program, we take 4-minute exposures through a broad VR filter covering as many fields as possible per night with each field visited twice at a separations between exposures of approximately 2 hours. We use 2x2 on-chip binning in order to reduce read out time and data volume.

NOAO's Mosaic wide field optical imager mounted on the KPNO 0.9-meter telescope. The Deep Ecliptic Survey is being conducted with the Mosaic Cameras on the 4-meter Mayall and Blanco telescopes at Kitt Peak National Observatory (KPNO) and Cerro Tololo InterAmerican Observatory (CTIO), respectively.
Photo credit: NOAO/AURA/NSF.

 

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