TITLE:   GCN CIRCULAR
NUMBER:  4566
SUBJECT: GRB 060121: Liverpool Telescopes optical limits
DATE:    06/01/23 11:00:54 GMT
FROM:    Carole Mundell at ARI, JMU,Liverpool  <cgm@astro.livjm.ac.uk>

A. Monfardini, A. Melandri, C. Guidorzi, C.G. Mundell, A. Gomboc,
I.A. Steele (Liverpool JMU) on behalf of the Liverpool GRB group report:

 "On Jan 21.968 UT and Jan 22.035 UT the Liverpool Telescope imaged the
 field of GRB060121 (HETE alert 4010, Arimoto et al., GCN 4550;
 Prigozhin et al. GCN 4551), beginning at 0.83 and 2.44 hours after the
 GRB, respectively. Images were taken with r', i' and z' filters.

 The SXC error circle (Prigozhin et al. GCN 4551) was partially covered
 (about 50%) during the first hour of observations. In the second hour
 it was entirely inside the Liverpool Telescope 4.6 arcmin field of
 view, as was the Swift-XRT error circle provided by Mangano et
 al. (GCN 4560).

 The optical counterpart suggested by Malesani et al. (GCN 4561) and
 Levan et al. (GCN 4562) is not detected in our images. Manual
 inspection reveals no afterglow candidate down to a magnitude limit of
 r'> 22.5, i'> 22.2 and z'> 21.6 at approximately 2.7 hours after the
 burst. The limits are determined by comparison with SDSS pre-burst
 photometry.

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