GCN Circular 7484

Veli-Pekka Hentunen (Varkaus, Finland), Arto Oksanen (Muurame, Finland),
and Petri Kehusmaa (Hyvinkaa, Finland) report to the AAVSO High Energy
Network the following optical detections and upper limits of GRB 080319B
(Racusin et al., GCN Circular #7427
Loading...
 
 ):

Veli-Pekka Hentunen and Markku Nissinen (Taurus Hill Obs., Varkaus,
Finland) report the detection of the optical afterglow of GRB 080319B
(Racusin et al., GCN Circular #7427
Loading...
 
 ).  The afterglow was observed
unfiltered for a total of 1500 seconds using an SBIG ST8-XME CCD mounted
on a Meade LX200 0.3-m telescope.  Observations commenced approximately
15.3 hours post-burst; the mid-point of the observations was 2008 March
19.8999 UT. The afterglow was clearly detected at an unfiltered
magnitude of 19.08 +/- 0.02, calibrated relative to USNO-A2.0
1200-07324239.

A detailed report of this observation is available at the following URL:
ftp://ftp.aavso.org/grb/Veli-PekkaHentunen_080319B_2454545.53358_.txt

A FITS image of this observation is available at the following URL:
ftp://ftp.aavso.org/grb/Veli-PekkaHentunen_080319B_2454545.53358_.fits


Petri Kehusmaa (Slope Rock Observatory, Hyvinkaa, Finland) reports a
non-detection of the optical afterglow of GRB 080319B.  The afterglow
was observed through a V filter for a total of 1800 seconds using an
SBIG ST-7XME CCD mounted on a 0.2-m telescope.  Observations commenced
approximately 17 hours post-burst; the mid-point of the observations was
2008 March 19.9675 UT.  The afterglow was not detected in the V-band
with an upper limit of R=17.6 (calibrated relative to USNO-A2.0).

A detailed report of this observation is available at the following URL:
ftp://ftp.aavso.org/grb/PetriKehusmaa_GRB080319B_2454545.93778_.txt

A FITS image of this observation is available at the following URL:
ftp://ftp.aavso.org/grb/PetriKehusmaa_GRB080319B_2454545.93778_.fits

Arto Oksanen and Olli-Pekka Reimaala (Hankasalmi Obs., Hankasalmi,
Finland) also report the detection of the optical afterglow of GRB
080319B.  The afterglow was observed unfiltered for a total of 2040
seconds (17 x 120s) using an SBIG STL-1001E CCD mounted on an RC Optical
Systems 0.4-m telescope. Observations commenced approximately 19.3 hours
post-burst; the mid-point of the observations was 2008 March 20.0639 UT.
The afterglow was clearly detected at an unfiltered (CR) magnitude 19.0
+/- 0.1, calibrated relative to USNO-A2.0. Note that this magnitude uses
a different comparison star from that of Hentunen and Nissinen (see
above), and may be offset by a few tenths of a magnitude.

A detailed report of this observation is available at the following URL:
ftp://ftp.aavso.org/grb/ArtoOksanen_GRB080319B_2454545.72325_.txt

A FITS image of this observation is available at the following URL:
ftp://ftp.aavso.org/grb/ArtoOksanen_GRB080319B_2454545.72325_.fits

The AAVSO thanks the Curry Foundation for their continued support of the
AAVSO International High Energy Network.