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GCN Circular 18537

GRB 151027A: Continued P60 Monitoring
2015-10-30T14:37:08Z (9 years ago)
S. Bradley Cenko at NASA/GSFC <>
S. B. Cenko (NASA-GSFC) and D. A. Perley (DARK/NBI) report on behalf of a larger collaboration:

We have continued to image the optical afterglow of GRB151027A (Maselli et al., GCN 18478) with the robotic Palomar 60-inch telescope (see Perley et al., GCN 18481). We report the following r�-band photometry, calibrated with respect to nearby point sources from the APASS survey:

t_mid                                time since burst (d)          Magnitude
2015-10-29T02:14:14      1.93                                   19.63 +/- 0.04
2015-10-30T02:02:28      2.92                                   20.48 +/- 0.08

This implies a relatively steep power-law decay index of ~ 1.9 at these times.

Continued observations are planned.
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