GCN Circular 28026
Subject
GRB 200623A: MMT observations at XRT Source #3
Date
2020-06-24T21:47:34Z (5 years ago)
From
Jillian Rastinejad at Northwestern Univ. <jillianrastinejad2024@u.northwestern.edu>
J. Rastinejad, Y. Dong, W. Fong, K. Paterson, and A. Rouco Escorial (Northwestern) report:
"We observed the location of the short-duration GRB 200623A at the position of XRT source #3 (Tohuvavohu et al. GCN 28023) within the GRB localization (Fermi GBM Team GCN 28011, DeLaunay et al. GCN 28013) with the MMTCam mounted on the MMT 6.5-meter telescope on Mount Hopkins, Arizona. We acquired 18 x 120-sec observations in the r-band at a mid-time of 2020 June 24.18 UT (25.03 hrs post-burst). The observations have a mean airmass of 1.11, seeing of 1.36", and were taken in thin clouds.
In the vicinity of the XRT Source #3 position, we detect several sources that are also apparent in SDSS and Pan-STARRs imaging. We find the brightest nearby galaxy, SDSS J160758.62+532842.2 (D���Avanzo et al. GCN 28021) to be consistent with the catalogued magnitude in SDSS (Alam et al. 2015). At the position of the XRT source, the 3-sigma limiting magnitude within the error circle is r > 23.1 AB magnitude, calibrated to SDSS and not corrected for Galactic Extinction. We note that our imaging was not deep enough to detect the faint source found by D���Avanzo et al. (GCN 28021).
Further observations are planned. We thank the MMT staff for their assistance with planning and executing these observations."
[GCN OPS NOTE(24jun20): Per author's request, "GRB 200624A: " was added to the SUBJECT field of the circular.]