The data processing pipeline for Vulcan Camera images can be divided
into several discrete steps: star field preparation, image calibration, image
reduction, and transit detection.
The first step consists of selecting stars to be monitored and preparing
an initial catalog file of each star's position and brightness on a reference
frame.
The second step is the generation of nightly and seasonal calibration
images. We normally take several bias, dark, and flat frames at the beginning
and end of each night. These images are combined to generate an average
bias, dark, and flat for each night. We also create master calibration images
from the average of all of the nightly files.
The third step is the systematic reduction of images.
The final step is an automated search of the light curves. We use
matched-filter detection routines to search for transits. The data are
filtered using a transit signal of a user-specified duration (generally
one to three hours), and then folded over a range of periods. The period
and phase resulting in the maximum sigma statistic is returned for each
star, along with statistics to help assess the significance of the detection.
A screen-shot from the Transit Detection Algorithm showing the strong signal
(25 sigma) for a grazing eclipsing binary system discovered by Vulcan.
