[vsnet-grb-info 7763] ICSP VLF observation of GRB090427 from two receivers

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9317
SUBJECT: ICSP VLF observation of GRB090427 from two receivers
DATE:    09/05/01 13:43:55 GMT
FROM:    Sandip K. Chakrabarti at S.N. Bose Nat. Centre for Basic Sci.  <chakraba at bose.res.in>

ICSP VLF observation of GRB090427 from two receivers

Sushanta K. Mondal (ICSP), Sandip K. Chakrabarti (S. N. Bose Centre and ICSP),
Narendra N. Patra (Univ. Pune) and D. Bhowmick (ICSP)

Two ICSP VLF receivers clearly observed the effects of GRB090427
(GCN#s 9277, 9296) on the ionosphere simultaneously. The subflare point
(13.5d S, 28.2d E) being closer to western India the signal was prominent
from our Pune receiver (18.5d N, 74d N) while it was weaker at our
Kolkata (22.5N, 88.5d E) receiver in eastern India. These two stations were
~1000 miles apart.

Both the receivers detected the GRB right after triggering and the
correlation of the signals were found excellent for about ~70 seconds.
Before the triggering, the correlation was poor.

A comparison of the smoothed signals can be found in grb27GCN.jpg in
http://www.bose.res.in/~chakraba/grb090427-1.html. This message may be cited.