[vsnet-chat 1869] BVRI photometric file update

[bas@lowell.Lowell.Edu (Brian Skiff)]

     I have added several major lists of stars to my growing (burgeoning!)
all-sky BVRI photometric reference file.  This now contains over 27000 stars
fainter than V=10.0 with a median value near V=14.0.  Although it contains
a selection of primary standard stars, the bulk of the data are not of high
photometric accuracy, and are intended for use in calibrating photographic
surveys and current wide-field digital surveys at the ~0.05 mag. level.
Included are equinox 2000 coordinates, GSC identifications, and V magnitudes
and BVRI colors.  The files can be obtained from the Lowell ftp area at:

http://ftp.lowell.edu/pub/bas/starcats/loneos.phot        (1.9Mb uncompressed)
http://ftp.lowell.edu/pub/bas/starcats/loneos.phot.gz     (509Kb compressed)

A small bibliographic reference file is at:

http://ftp.lowell.edu/pub/bas/starcats/loneos.ref         (77Kb)

...which gives a hint at the range of sources I've drawn from.  A date given
at the top of each file shows when the file was last amended, as I typically
do so once or twice per week.  A few sample lines are given at the bottom of
this message.
     The current version has been augmented with additional data from two
major series.  About 1500 stars in several dozen southern fields have
been gleaned from the Yale southern proper-motion survey (see Platais et al.
1998, AJ 116, 2556).  In brief, nearly all the high-latitude southern GSPC-I
sequences from -40 to -25 Dec (inclusive) have been extended to mag. 17 with
15-20 stars.  The complete Yale list of some 8000 stars was trimmed by 
selecting about four stars per magnitude interval (roughly 11 < V < 18), and 
comparing this sample against USNO-A2.0 to omit stars with close companions to
yield a "clean" subset of isolated stars.  Another ~950 stars have been added
from sequences published by Boyle et al. (1995 MNRAS 276, 33).  These include
fourteen high-latitude equatorial fields with BVRI photometry down past
V mag. 20.  Another few thousand stars have been added from numerous papers
containing small lists of mostly BV photometry of brighter stars.  The southern
galactic plane in particular has been beefed up considerably with stars of
intermediate brightness.  Finally, sequences by Arne Henden have been added as
he makes them available.  In total, about 5000 stars have been added in the
last month.  The bibliographic file is now much more nearly complete.
     Another minor change to the file is that "real" bona-fide primary and
high-weight secondary standard stars are now marked explcitly with an asterisk
in column 55, immediately left of the V magnitude.  This is not yet complete,
but I will gradually make it more so as I go through the data.  At the
moment only the Landolt equatorial standards are flagged, along with selected
other stars.  This tiny minority of stars can be used for instrumental
calibration when doing full-up "all-sky" photometry.  The vast number of
remaining stars _are_not_standard_stars_, and should not be used as such.
They are nevertheless useful for most purposes.
     More data yet to come....

\Brian



Name                  RA  (2000)  Dec    s     GSC       V    B-V   V-R   V-I
V363_CAS            0 16 10.8  +60 17 38 h  4014-1021  13.33  1.44  0.80  1.53
V363_CAS            0 16 11.1  +60 21 22 h  4014-0423  12.60  0.60  0.36  0.72
V363_CAS            0 16 11.3  +60 17 10 h             14.94  1.14  0.70  1.37
BPS CS 31069-64     0 16 12.4  +04 49 35 A  0005-0644  13.89  0.59 
SA 68-Be15          0 16 16.0  +15 48 25 A             20.70  0.71      
BPS CS 22961-51     0 16 16.3  -31 06 33 A  6990-0630  14.55  0.32
SA 68-Be10          0 16 17.3  +15 48 06 A             19.99  0.89      
SJB c01-05          0 16 18.0  +05 07 49 b             17.83  0.70  0.40
SJB c01-11          0 16 18.4  +05 03 41 b             17.68  0.92  0.49
FO_CAS              0 16 22.1  +60 43 15 h  4014-2646  12.88  1.19  0.70  1.32
NGC 55 HG3          0 16 22.7  -39 31 16 G  7524-0022  13.72  0.87

VSNET Home Page

Return to Daisaku Nogami

---

vsnet-adm@kusastro.kyoto-u.ac.jp