GCN Circular 8375

Subject

Detection of flare star Algol in Swift-BAT slew data

Date

2008-10-14T18:47:45Z (18 years ago)

From

Antonio Copete at Harvard U <acopete@head.cfa.harvard.edu>

A. Copete, J. Grindlay (Harvard), S. Barthelmy (GSFC)

We report on an independent detection of the flare star Algol from  
Swift-BAT slew data that precedes the BAT detection reported by L.  
Vetere et al (GCN 8371Loading...
 
 ). On the slew that began on 10/13/08 at  
21:16:47 UT and lasted 129sec, ending 4sec before the trigger in  
spacefraft pointing mode, Algol had an exposure time of 80.60sec and  
is detected as a high-significance source in both the 15-50keV and  
15-150keV energy bands (12.6 and 10.7 sigma, respectively). The  
calculated location is:
   RA(J2000) =  03h 08m 11s
   Dec(J2000) = +40d 59' 42"
with an uncertainty of 3.0arcmin (90% radius). The derived 15-50keV  
band flux is 343 mCrab. Prior to this detection, Algol fell within the  
BAT slew survey field-of-view in the slews that began at 20:54:02 UT  
and lasted 158sec, and at 19:57:02 UT and lasted 109sec, but in  
neither case was it detected at a significance greater than 3.5sigma.