[vsnet-grb-info 3000] GRB 060218/SN 2006aj, SMARTS optical/IR observations

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4837
SUBJECT: GRB 060218/SN 2006aj, SMARTS optical/IR observations
DATE:    06/02/26 18:43:22 GMT
FROM:    Bethany Cobb at Yale U  <cobb at astro.yale.edu>

B. E. Cobb and C. D. Bailyn (Yale), part of the larger SMARTS
consortium, report:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained optical/IR imaging of the position of GRB 060218/SN 2006aj
(GCN 4775, Cusumano et al.) over 5 nights.  Total summed exposure time
on each night amounted to 36 minutes in I and 30 minutes in J.

The object shows continued brightening over our images. The preliminary 
I magnitude of the object on 2006-02-22 is calculated based
on contemporaneous observations of Landolt RU149.  The preliminary J 
magnitude on the same day is calculated in comparison to 2MASS 
stars in the field.

Mid-Exposure
UT Date and Time
2006-02-22 00:35     I = 17.58 +/- 0.05              J = 17.31 +/- 0.05

                  I mag relative to 1st epoch  J mag relative to 1st epoch
2006-02-23 00:27        -0.18 +/- 0.02                  -0.11   +/- 0.05
2006-02-24 00:20        -0.29 +/- 0.02                  -0.24   +/- 0.05
2006-02-25 00:16        -0.39 +/- 0.02                  -0.28   +/- 0.05
2006-02-26 00:18        -0.46 +/- 0.02                  -0.38   +/- 0.05