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Arne Henden Photometric Standards Sky Databases (SDBs)
Culled version by Brian Warner Total 42,118 (3 MB) stars only >=3 observations and a V error <=0.2 Sample of TheSky display NGC7331 data Warning quite large! The above photometric datasets are compressed or "ZIPPED" files. They must be uncompressed first. Each ZIP file contains the DAT file and the compiled Sky Database file. Place the files into the default "..\TheSky6\Data\User\SDBs" folder then "add" them to your existing list of Sky Databases using the Data | Sky Database Manager's "ADD" button. See below.
Add the data you want
by highlighting them and pressing "Add" Also, I have chosen to compile the datasets as type "REFERENCE POINTS" not stars so they can be easily identified! And because the datasets have been compiled as object type "Reference Point" these must be set to visible to see them! Use the View | Display Explorer to check this. Just type in "Reference Point" in the field "Go to:" and you are taken directly to the object type "Reference Point". See below. Place a check next to "Reference Point" to make them visible. View | Display Explorer Note: You can also if you like make your own custom symbol rather than using any of the defaults. Example for NGC7331 NOTE: The small turquoise reference markers are the Henden photometric standards from the above NGC7331 dataset. The default color for Reference Point is actually RED! Accuracy of the stars positions NOTE: A personal observation.
From my own personal experience with the above datasets the coordinates for the stars (RA and DEC) from all of the above seem to be off slightly when compared to the 102 Palomar Sky Survey digital images or comparing to the 1 billion stars from the USNO-B1 data and/or the smaller but accurate UCAC2 stellar data. That is why the reference markers do not match perfectly to the stars in the photograph or the stellar data plotted by TheSky. If you see an error on the order of 0.25 to 0.5 arc seconds you need not be concerned. As far as I am able to tell that is not out of the question for this photometric data where more important than accurate positions is accurate magnitudes. Sample Screen However, for the most part their positions are close enough to not present a problem in identifying them and after all these stars are accurate in regard to photometric content not necessarily extremely accurate in positions nor do I believe there are claims to that effect. Please correct me if I am wrong. Data Copyright README file Henden field photometry 08 April 2002 Arne A. Henden (aah@nofs.navy.mil) These files are for use by the general community. They represent a fair investment of time, so I would appreciate it if you would at least place an acknowledgement in any publication that uses this information. If you use these files for any datamining activity other than pure calibration of field/comparison stars, I request that you contact me before publication. Reading the .dat files Lew Cook has developed an Excel spreadsheet to plot the files; see http://www.lewcook.com/AAHPlot.htm |
