Photometric Standard Fields

Here is a current list of my photometric standard fields.

U,B,V,R,I give the number of standards in each filter, where a standard has at least 5 observations made under photometric conditions and sigma(mag) < 0.02 mag in a given filter.

The coordinates given are the (2000.0) coordinates of the field center. This may be followed by field size in arcminutes (RA, Dec).

Each field is represented by three files:

1. *.pos -- The (2000.0) positions of the stars in (a) RA, Dec in decimal degrees; (b) RA, Dec in hexagesimal HH MM SS.S sDD MM SS; (c) offsets in arcsec from a given reference position; (d) position, in pixels, in the image described below.

2. *.pho -- The photometric data [mag, sigma(mag), N(obs)] for U, B, V, R, I, plus a measure of variability: sigma(1 obs).

3. *.fits -- A composite image of the field. All images consist of short integers, and have x increasing East and y increasing North. The scale is an integer number of pixels per arcsecond, usually two pixels per arcsecond (0.500 arcsec/px) but sometimes, depending on the seeing, three or even four pixels per arcsecond. The scale factor (number of pixels per arcsecond) is the third number in the header keyword OFFSCALE.

If the field size is given, that means the field is ready now; the others are in various stages of progress. Feel free to encourage progess on any fields of particular interest to you.

Last modified: Wednesday, 24-Apr-2013 11:21:47 PDT