GRB 090531A
GCN Circular 9476
Subject
GRB 090531A: SARA upper limit
Date
2009-06-01T17:27:55Z (16 years ago)
From
Adria C. Updike at Clemson U <aupdike@clemson.edu>
Gary Henson, Shannon Hall, Mark Gorski (ETSU/SARA REU), Adria Updike,
Dieter Hartmann (Clemson University) report:
The 0.9m SARA telescope located at Kitt Peak National Observatory began
imaging the field of GRB 090531A (Stamatikos et al., GCN 9454) about 2.5
hours after the burst under decent weather conditions. In one hour of
stacked exposures, we detect no new sources down to a limiting magnitude
of R > 20.5 (with respect to the USNO B.1 catalog). No further
observations are planned.
GCN Circular 9525
Subject
Swift XRT observations of GRB 090531A
Date
2009-06-18T16:21:56Z (16 years ago)
From
Boris Sbarufatti at INAF-IASF-Pa <sbarufatti@ifc.inaf.it>
B. Sbarufatti, V. Mangano (INAF-IASFPA) on behalf of the Swift-XRT team.
The XRT onboard Swift observed the field of GRB 090531A on 2009 June
10 and 2009 June 17, after it came outside the Moon observing
contstraint, for a total exposure of 35.5 ks in Photon Counting mode.
Three significant sources are detected inside the initial BAT error
circle (Stamatikos, et al., GCN circ. 9454). Two of them, detected at
a level of 1.2E-3 counts/s and 9.0E-4 counts/s, are compatible with a
stable count-rate and are found outside the BAT refined error circle
(Sakamoto, et al., GCN circ. 9460). The third source, detected at a
level of 6.5E-4 counts/s is too faint to estimate if it is fading or
not, and it is found just inside the BAT refined error circle, at a
distance of 64.8 arcsec from the BAT refined position. Its coordinates
are RA,Dec = 178.65539, +7.81671 which is:
RA(J2000) = 11h 54m 37.29s
Dec(J2000) = +07d 49' 00.2"
with an uncertainty of 4.8 arcsec (radius, 90% confidence).
This circular is an official product of the Swift-XRT team.
GCN Circular 10016
Subject
GRB 090531A: Skynet/PROMPT Observations
Date
2009-10-11T21:32:42Z (16 years ago)
From
Aaron LaCluyze at U.North Carolina <lacluyze@physics.unc.edu>
A. LaCluyze, D. Reichart, J. Haislip, K. Ivarsen, A. Foster, J. Moore, A.
Oza, M. Schubel, J. Styblova, A. Trotter, J. A. Crain, and M. Nysewander
report:
Skynet observed the Swift/BAT localization of GRB 090531A (Stamatikos et
al., GCN 9454) with three of the 16" PROMPT telescopes at CTIO beginning
6.1 minutes after the trigger in UVRI.
We do not detect the afterglow (Sbarufatti & Mangano, GCN 9525). Stacking
only images that increase the limiting magnitude yields:
mean 1-sig. 1-sig.
time 3-sig. sys. stat.
since lim. cal. cal. cal.
trig. tel. exp. fil. mag. stars* unc. unc.
(m) (# x s) (mag) (mag)
6.5 PROMPT-5 1 x 40 I 17.6 32 SDSS 7 0.055 0.002
15.3 PROMPT-5 11 x 80 I 19.4 32 SDSS 7 0.055 0.000
84.0 PROMPT-3 75 x 80 U 19.3 7 SDSS 7 0.037 0.001
92.6 PROMPT-5 85 x 80 I 20.5 32 SDSS 7 0.055 0.000
+ 1 x 40
94.1 PROMPT-4 43 x 80 V 21.1 37 SDSS 7 0.007 0.000
104.8 PROMPT-4 54 x 80 R 21.3 40 SDSS 7 0.018 0.000
* Transformed using Jester et al., 2005, ApJ, 130, 873.