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GCN Circular 990

GRB010222 Optical observations
2001-02-25T20:14:35Z (23 years ago)
Arto Oksanen at Nyrola Obs., Finland <>
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 

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

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