K. Ohta (Kyoto Univ.) and M. Akiyama (Subaru) report:
We have imaged the central region of the error circle of
GRB 020331 with the SQIID equipped to KPNO 2.1m telescope.
The field is centered on 13h16m22.7s and -17d55'23" (J2000)
with a field of view of about 5'x5'.
The J-, H-, and K-band images were taken simultaneously
at 7:06 (Apr 1st) (UT). A total integration time is 15min
for each band.
We have found the following two NIR objects that are not seen
in the Digitized Sky Survey, APM catalog, and 2MASS images.
#1 13h16m29.5s -17d55'08" (J2000), J=17.7, H not measurable, K=16.8
#2 13h16m23.2s -17d56'11" (J2000), J=17.6, H=17.2, K=16.8
Accuracy of the coordinates is about 0.5".
Photometry was roughly made using 2MASS objects
exposed in the same frame; accuracy seems to be less than
0.1 mag (J-band), 0.3 mag (H-band), and 0.5 mag (K-band).
There is a possibility that these objects are not seen in
the POSS merely because they are red objects.
If one of them will fade, it should be a candidate of the
afterglow of the GRB. Further NIR observations are desirable.
This message may be cited.