TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  600
SUBJECT: GRB 000301c: K' observations
DATE:    00/03/09 15:02:12 GMT
FROM:    James Rhoads at STScI  <rhoads@stsci.edu>

James Rhoads and Andy Fruchter (STScI) report:
 
We observed the candidate counterpart of GRB 000301c again on March 8.590
in the K' filter using the NASA IRTF + NSFCam.  The magnitude of the transient
relative to the reference star 6" west has decayed further to +3.32 +- 0.09,
giving K'=19.28 +- 0.09 (statistical error only).
This is a decay of 0.72 magnitudes in the two days since our preceding
observation (on March 6.595 UT).

This continued decay is in marked contrast to the "standstill" of the
optical flux reported by Bernabei et al (GCNC 599), and leads us to
believe that the source most likely is the transient counterpart of
GRB 000301c despite its erratic behavior.  The near-IR flux showed a
comparable "standstill" behavior earlier (GCNC 572, 577, 586, 587) and then
entered a steeper decline.  The total decay to date in K' has been 1.76
magnitudes, and during the 72 hours preceding this observation the K' flux
decayed approximately as t**(-2.2).

Extrapolation of this object's light curve from earlier data appears
fraught with difficulty.  Further observation is therefore strongly
urged at all wavelengths.