TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  990
SUBJECT: GRB010222 Optical observations
DATE:    01/02/25 20:14:35 GMT
FROM:    Arto Oksanen at Nyrola Obs., Finland  <arto.oksanen@tietoenator.com>

A. Oksanen, M. Moilanen, H. Hyvonen, R. Pasanen, and
P. Tikkanen of the Nyrola Observatory GRB team and
the AAVSO International GRB network, report:

We observed the optical transient for GRB010222 (GCN 961) with
the 0.4m telescope and ST7E CCD camera of the Nyrola
Observatory on the night of 010222/010223 UT. Observing conditions 
were quite good: sky was clear, but strong wind enlarged the star
images. Our preliminary untransformed BVR measures of the OT (GCN 961)
from that night, using Henden star A (GCN 967) as calibrated by 
Henden (GCN 987) for the comparison star, are as follows:

UT (mid)        mag   merr  filter exposure(s)
----------------------------------------------
20010222.8227  19.84  0.31   B     12x300
20010222.8744  19.57  0.13   Rc    12x300
20010222.9187  19.70  0.13   V     12x300
20010222.9661  19.69  0.15   Rc    12x300
20010223.0134  19.92  0.14   V     12x300
20010223.0628  19.92  0.17   Rc    12x300
20010223.1439  20.29  0.21   V      6x300
20010223.1665  20.11  0.31   Rc     6x300

The images are available on http://nyrola.jklsirius.fi/grb/grb010222/. 

We want to thank A. Henden (USRA/USNO) about preparing this circular.

This message can be cited.