GCN Circular 33488
Subject
GRB 230314A: TURBO Optical Upper Limit
Date
2023-03-20T20:52:00Z (a year ago)
From
Robert Strausbaugh at University of Minnesota <rstrausb@umn.edu>
R. Strausbaugh (UMN), D. Warshofsky (UMN), P. L. Kelly (UMN), M. Tran (UMN)
report on behalf of a larger collaboration:
We observed the GRB 2303014A (Fermi GBM Team, GCN 33474) field with the
Total-Coverage Ultrafast Response to Binary-Mergers Observatory (TURBO)
prototype telescope in St. Paul, Minnesota on March 14, from 05:02 to 08:36
UT (corresponding to 2.01 to 5.52 hours after GRB trigger) in SDSS g and
r-band filters.
We acquired a series of 30x60s exposures over the entire observing period
in each band covering an area of about 12 square degrees with corners for
each field listed in the table below. We do not detect any fading sources
in the GBM error region in either band, consistent with available optical
upper limits (Lipunov et al., GCN 33249).
The following 3-sigma upper limits in AB magnitudes are calculated using
the Pan-STARRS catalog as reference:
Filt. | Corners of fields (hh:mm:ss,dd:mm:ss)| Upper Limit
���---------------------------------------------------------------------------------------------
g | (15:08:41,+75:20:31) ,(16:08:31,+74:24:12) |18.2
���---------------------------------------------------------------------------------------------
r | (16:06:24,+75:12:04) ,(15:08:34,+74:04:37) |18.6
���---------------------------------------------------------------------------------------------
g | (15:20:58,+75:20:08) ,(16:20:45,+74:23:31) |18
���---------------------------------------------------------------------------------------------
r | (16:18:28,+75:12:01) ,(15:20:35,+74:03:47) |18.7
���---------------------------------------------------------------------------------------------
g | (15:12:17,+73:21:35) ,(16:05:17,+72:25:04) |18.3
���---------------------------------------------------------------------------------------------
r |(16:03:27 ,+73:12:08) ,(15:12:06,+72:04:05) |18.7
���---------------------------------------------------------------------------------------------
g | (15:24:16,+73:21:38) ,(16:17:16,+72:25:03) |18.1
���---------------------------------------------------------------------------------------------
r | (16:15:22,+73:12:30) ,(15:23:58,+72:04:42) |18.7
���---------------------------------------------------------------------------------------------
g | (15:04:23,+77:18:32) ,(16:13:02,+76:22:15) |18.2
���---------------------------------------------------------------------------------------------
r | (16:10:49,+77:10:25) ,(15:04:38,+76:01:38) |18.6
���---------------------------------------------------------------------------------------------
g | (15:16:20,+77:18:47) ,(16:24:59,+76:22:30) |18.1
���---------------------------------------------------------------------------------------------
r | (16:22:46,+77:10:29) ,(15:16:35,+76:01:37) |18.7
These magnitudes are not corrected for foreground Galactic extinction.
The TURBO prototype in St. Paul consists of two co-mounted 11-inch
telescopes each with a 6.6 square degree field of view. TURBO will consist
of two arrays of 8 pairs of co-mounted 11-inch telescopes at two dark-sky
sites: Magdalena Ridge Observatory, New Mexico, USA and Skinakas
Observatory, Crete, Greece.