Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 668

GRB000508B, optical photometry
2000-05-10T22:57:10Z (24 years ago)
Krzysztof Z. Stanek at CfA <>
K. Z. Stanek (CfA), P. M. Garnavich (Notre Dame), P. J. Groot, S. Jha
(CfA) and M. Hicks (JPL) report:

We have observed most of the RXTE/ASM-IPN error-box of GRB 000508B
(GCN 665) using the FLWO 1.2-meter telescope on Mt. Hopkins and the
KPNO 2.1m telescope. The center of the GRB 000508B error-box is
located at Galactic coordinates (l,b)=(0.48 deg,14.38 deg), and the
Schlegel et al. (1998) Galactic reddening toward this direction is
E(B-V)=0.51 (A_V=1.7 mag). Due to the proximity to the Galactic plane
the stellar field is fairly dense.

At KPNO we obtained four 600 sec R-band images, the first two at UT
May 10 07:30 and the second two at UT May 10 11:33. At FLWO we
obtained two 600 sec R-band images, first one at UT May 10 06:39 and
the second one at UT May 10 09:14. In addition, at FLWO we have
obtained UBVI images for the field. Using DAOPHOT-II (Stetson 1992) on
the FLWO 1.2-meter R-band image we detect about 5,000 objects with
R<22.5 in 11x11 arcmin field.

Visual comparison with the POSS-II red plate reveals no obvious
``new'' objects. Employing the image subtraction code ISIS-2 (Alard
1999) between the two epochs taken at each telescope reveals four
possible variable objects located in the error-box, with the following
coordinates and magnitudes from Henden et al. (GCN 667):

V1) RA=253.58616  DEC=-20.41683  V=16.75

V2) RA=253.54913  DEC=-20.46479  V=17.33

V3) RA=253.53600  DEC=-20.43531  V=17.72

V4) RA=253.60865  DEC=-20.42111  V=18.24

All of these objects are easily identified on the POSS-II plate, so
most likely NONE of these objects is the optical counterpart to GRB
000508B. Further observations are planned at FLWO.

This message can be cited.
Looking for U.S. government information and services? Visit