Differential Ensemble Photometry by Linear Regression

Volume 38 number 2 (2010)

Kevin B. Paxson

Abstract

A linear regression method for multiple star ensemble photometry by spreadsheet is presented. After initial spreadsheet setup and data entry, a differential ensemble magnitude estimate is calculated along with a total error. Ensemble photometry by linear regression allows one to see the distribution of comparison star errors, yields variable star estimates with enhanced confidence, and identifies potential problems with the comparison stars, validating the Johnson V magnitude sequence. Spreadsheet construction is described and two linear regression ensemble examples are illustrated and discussed.