A Novel Double-Imaging CAMera (ANDICAM)

The ANDICAM is an imaging instrument capable of simultaneously recording images at an optical and an infrared wavelength. The primary purpose of the instrument is for microlensing event follow-up to look for the presence of planets and other anomalous behaviour. Two copies of the instrument are currently being built at the Ohio State University under the direction of Dr. Darren Depoy for PLANET: The scientific goals of the instrument demand the highest possible photometric precision at a wide range of wavelengths. Most projects also require a field-of-view large enough to include many comparison stars, in order to insure accurate relative photometry even in marginal conditions. Accordingly, the instruments were designed to produce a plate scale of 0.3" per pixel onto both optical and infrared detector arrays so that a stellar point-spread-function is very well sampled. The optics will fully illuminate a 2048x2048, 15 micron pixel CCD and a 1024x1024, 27 micron pixel infrared array, which should guarantee that sufficient comparision stars are available.

Both ANDICAM and DANDICAM share optical, mechanical, electronic, and software designs and will have similar CCDs and IR array detectors (see figure above). The quantum efficiency and cosmetics of the CCDs are excellent (see figure below). The throughput of the instrument should be excellent at all wavelengths from U to K. The U sensitivity in particular should be very high, since the CCD quantum efficiency is very good at U and the instrumental optics are designed to work well at U. Of course, there is no substitute for actual measurements, but the throughput at U should be >20% (including telescope and atmosphere), and >40% for BVRIJHK.

The optical portion of ANDICAM has been deployed at the CTIO/Yale 1-m telescope and saw first light on 6-7 June 1998, taking a total of 36 PLANET images. The infrared channel was installed at CTIO in 1999. Deployment of the complete optical-IR DANDICAM to South Africa has now taken place, and engineering tests are proceeding in March 2000. For more details on ANDICAM and DANDICAM, check out the OSU ANDICAM website, including schematics and pictures of what is actually happening at the Ohio State astronomical instrument lab.

back to the PLANET Homepage