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Arne Henden's
Photometric Standards
Culled
version by Brian Warner Total 42,118 (3 MB) stars
only >=3 observations and a V error <=0.2
Warning quite large!
Total 519,860 objects!
The above photometric datasets are
ZIPPED files. They must be
uncompressed to use. 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"
Add individuals or multiples at a time
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
Enable Reference Point
Note: You can also if
you like make your own custom symbol rather than using any of the defaults.
Example for NGC7331
Reference Points plotted from NG7331.DAT
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!
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
Showing positional error on the order of 0.5
arcseconds
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.
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
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