New White Dwarf Appears on Cerro Tololo

Early in January the skyline of Cerro Tololo was modified by the appearance of a new dome, ten feet in diameter, housing a robotic H survey camera. With an optical system of only 0.031-meter aperture (a Canon 50-mm f/1.6 lens), the installation merits its nickname of "El Enano" (the dwarf), but it beats all other telescopes on the mountain in sky coverage - 13 x 13 on a single CCD frame. Over the course of the next two years, the robot will survey the sky at H to a sensitivity limit of one Rayleigh (corresponding to an emission measure of 2 cm^-6 pc) at an angular resolution of about 1', comparable to the resolution of the IRAS survey. Like the IRAS survey, the H images will eventually be published on a CD-ROM and made available on the World Wide Web for study by anyone in the astronomical community.

The obvious scientific application of the survey is the study of the structure of the warm ionized component of the interstellar medium, but the survey also has applications to cosmology. Limits on the H brightness translate directly into limits on the microwave emission from Galactic hydrogen, a possible contaminant of the measurements of fluctuations in the cosmic microwave background.

The system is not just a remotely controlled telescope, but a true robot. It operates without human intervention, with two exceptions. First, to avoid attempts to observe in cloudy or stormy weather, the robot (via email) asks permission of the local observer support staff before opening the dome. (The dome can also be commanded to close via email.) Second, a technician enters the dome once a week to remove a full data tape and mail it to the project director. Otherwise the system operates completely autonomously. The camera was installed and subjected to initial shakedown tests in January. Routine robotic operations are expected to begin in May. Elapsed time from arrival of the dome and telescope dismantled in packing crates to first light was two weeks, possibly setting a record for facility construction!

The robotic camera system was designed and constructed by Wayne Rosing (Las Cumbres Observatory) and The Remote Telescope Company (Los Gatos, California). The project is under the scientific direction of John Gaustad (Swarthmore College) with the collaboration of Peter McCullough (University of Illinois) and Dave Van Buren (IPAC).