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A Performance Comparison for Two Versions of the Vulcan PhotometerAnalysis of the images produced by the first version (V1) of the Vulcan photometer indicated that two major sources of noise were sky brightness and image motion. To reduce the effect of the sky brightness, a second version (V2) with a longer focal length and a larger format detector was developed and tested. The first version consisted of 15-centimeter (cm) focal length, F/1.5 Aerojet Delft reconnaissance lens, and a 2048 x 2048 format front-illuminated charged coupled device (CCD) with 9 microns micropixels (Mpixels). The second version used a 30-cm focal length, F/2.5 Kodak AeroEktar lens, and a 4096 x 4096 format CCD with 9 micro pixels. Both have a 49-square-degree field of view (FOV) but the area of the sky subtended by each pixel in the V2 version is one-fourth that of the V1 version. This modification substantially reduces the shot noise due to the sky background and allows fainter stars to be monitored for planetary transits. To remove the data gap and consequent signal-level change caused by flipping the photometer around the declination axis and to reduce image movement on the detector, several other modifications were incorporated. These include modifying the mount and stiffening the photometer and autoguider structures to reduce flexure. This paper compares the performance characteristics of each photometer and discusses tests to identify sources of systematic noise.
Document ID
20010050213
Document Type
Conference Paper
Authors
Borucki, W. J. (NASA Ames Research Center Moffett Field, CA United States)
Caldwell, D. A. (NASA Ames Research Center Moffett Field, CA United States)
Koch, D. G. (NASA Ames Research Center Moffett Field, CA United States)
Jenkins, J. M. (Search for Extraterrestrial Intelligence Inst. Mountain View, CA United States)
Showen, R. L. (Raytheon Systems Co. Moffett Field, CA United States)
Date Acquired
August 20, 2013
Publication Date
February 1, 2001
Publication Information
Publication: Third Workshop on Photometry
Subject Category
Astronomy
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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