GCN Circular 30231
Subject
GRB 210610B: iTelescope optical afterglow observations
Date
2021-06-13T18:36:43Z (3 years ago)
From
Arto Oksanen at Nyrola Obs., Finland <oksanen@nyrola.jklsirius.fi>
Markku Nissinen (Taurus Hill Observatory, Varkaus, Finland) and Arto Oksanen
(Hankasalmi Observatory, Hankasalmi, Finland) report:
We have detected GRB 210610B optical afterglow (Page et al., GCN30170) using
iTelescope T18 (0.32-m f/8.0 + CCD in AstroCamp at Nerpio, Spain), iTelescope T21
(0.43-m f/6.8 + f/4.5 focal reducer + CCD in New Mexico Skies at Mayhill,
New Mexico, USA) and iTelescope T11 (0.50-m f/6.8 + f/4.5 focal reducer + CCD
in New Mexico Skies at Mayhill, New Mexico, USA).
We took total of 24 exposures with clear (CR), V and R filters.
The afterglow was clearly detected with each filter at the position
RA 16:15:40.43 DEC +14:23:57.4.
The following magnitudes were measured from comparison of a nearby star
(V = 13.97, r'=13.70) from the APASS DR9 catalogue (Henden+, 2016):
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JD UTC Mag Err Filter AirMass Telescope Exposure(s)
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2459376.36806 June 10 20:50 16.79 0.05 CR 1.28 T18 7x60
2459376.37868 June 10 21:05 17.15 0.10 V 1.24 T18 10x60
2459376.64285 June 11 03:25 17.76 0.02 CR 1.29 T21 2x300
2459376.65108 June 11 03:37 17.95 0.12 R 1.26 T11 5x300
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We used r' reference magnitude for the clear filter and the R filter measurements.