DAOPHOT - A computer program for crowded-field stellar photometry

Abstract

The difficult art of stellar photometry in crowded fields is currently undergoing a surge of popularity, and a number of different computer programs for deriving photometric information from two-dimensional digital images are currently in use. This paper describes one such program, DAOPHOT, which was written and continues to be developed at the Dominion Astrophysical Observatory. Emphasis is placed on the various types of philosophical and technical complications which arise when accurate photometry is sought for blended stellar images, and on the mathematical algorithms with which DAOPHOT attempts to deal with these complications, rather than on details of the coding. Some ways in which DAOPHOT resembles or differs from other similar programs are mentioned, and a discussion is presented of known shortcomings of the current program as well as possibilities for future improvement.

TEST The Tautenburg Exoplanet Search Telescope

“…The standard reduction is based on the ccdred package of Iraf/Pyraf(Doug Tody 1986). The psf-photometry is using the Source Extractor (Bertini & Arnouts 1996)to identify stars and the daophot package (Stetson 1987) to determine the brightness of the light sources. The astrometry is done by WCS-Tools using the USNO-A2 catalog.…”

A search for transiting planets in the Galactic Plane

“…The kernel size was also scaled to match the seeing. The DAOphot II code Stetson (1987) was used to detect and measure the fluxes of more than 500,000 stars on the reference image. PSF photometry of the difference images was performed for all detected stars using PySIS3.…”

Photometry of the SW Sextantis-type nova-like BH Lyncis in high state

“…The exposure time used was between 30 and 60 s. Some details of the observations are given in Table 1. After bias and flat-field corrections, the photometry was done with the standard DAOPHOT aperture photometry procedures (Stetson 1987). The magnitude of BH Lyn was measured relative to the star BH Lyn-5 (V = 14.47), and BH Lyn-4 (V = 15.30) served as a check (Henden & Honeycutt 1995).…”