[vsnet-grb-info 16717] Trigger 648422: Swift possible detection of a source in NGC4552

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17998
SUBJECT: Trigger 648422: Swift possible detection of a source in NGC4552
DATE:    15/07/09 22:02:08 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at milkyway.gsfc.nasa.gov>

A. Melandri (INAF-OAB), S. D. Barthelmy (GSFC),
M. G. Bernardini (INAF-OAB), P. D'Avanzo (INAF-OAB),
A. Y. Lien (GSFC/UMBC), B. Sbarufatti (INAF-OAB/PSU) and
M. H. Siegel (PSU) report on behalf of the Swift Team:

At 21:42:17 UT, the Swift Burst Alert Telescope (BAT) triggered and
located a possible source near NGC4552 (trigger=648422).  Swift did not slew
because of an earth-limb observing constraint.  The BAT on-board calculated
location is RA, Dec 188.824, +12.672, which is 
   RA(J2000)  =  12h 35m 18s
   Dec(J2000) = +12d 40' 20"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  We note that this is ~9 arcmin NGC 4552, and as such
it allows for a lower threshold value not the trigger criteria. 
As is typical for image triggers, there is nothing significant in the real-time
light curve. 

When the source location comes out of observing constraint (at T+49 minutes),
Swift will slew to it and then XRT and UVOT will produce their usual automated data
products.  And then a refined circular will be issued about the identity and
reality of this trigger. 

Burst Advocate for this burst is A. Melandri (andrea.melandri AT brera.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)