GCN Circular 577
Subject
GRB000301C, near-infrared observations (JHK' photometry)
Date
2000-03-03T23:39:15Z (25 years ago)
From
Naoto Kobayashi at SUBARU, NAOJ <naoto@naoj.org>
Naoto Kobayashi (Subaru Telescope, National Astronomical Observatory of Japan),
Miwa Goto, Hiroshi Terada (Kyoto University),
Alan T. Tokunaga (Institute for Astronomy, University of Hawaii),
on behalf of SUBARU Telescope team and SUBARU IRCS team
On 3 March, 12:48 UT - 13:54 UT, we observed the candidate optical
counterpart to GRB 000301C that was reported by Fynbo et al. (GCN
Circular #570). We used the Subaru 8m Telescope on Mauna kea with a
new instrument IRCS (Infrared Camera and Spectrograph for the Subaru
Telescope) during its first engineering run. Near-infrared J,H,K'
filters were used. The candidate optical transient (OT) was clearly
detected in all three bands.
We have performed preliminary photometry with 2-arcsecond aperture
using Persson standards taken during the night. The resultant magnitude
of the candidate OT was K'=17.6+-0.1 mag. For reference, the magnitude
of the near-by star, USNO 125_07686794, was estimated at K'=16.0+-0.05
mag.
Comparing to the estimated K' magnitude of 17.4 (at 4:41 UT - 5:38 UT)
reported by Stecklum et al (GCN Circular #572), our photometry may
suggest that the brightness decreased by roughly 0.2 mag during 8
hours. However, given the possible systematic errors for the two
estimates (e.g., photometric system is different), further
observations are necessary to confirm this OT candidate as the GRB
afterglow.
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