TITLE:   GCN CIRCULAR
NUMBER:  12985
SUBJECT: Swift Trigger 516027 is CC Eri
DATE:    12/02/24 19:35:10 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
M. M. Chester (PSU), N. Gehrels (NASA/GSFC),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
N. P. M. Kuin (UCL-MSSL), O. M. Littlejohns (U Leicester),
C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC),
A. Melandri (INAF-OAB), C. J. Mountford (U Leicester),
S. R. Oates (UCL-MSSL), P. T. O'Brien (U Leicester),
C. Pagani (U Leicester), K. L. Page (U Leicester),
D. M. Palmer (LANL), P. Romano (INAF-IASFPA), T. Sakamoto (NASA/UMBC),
B. Sbarufatti (INAF-OAB/PSU), M. Stamatikos (OSU/NASA/GSFC),
C. A. Swenson (PSU), G. Tagliaferri (INAF-OAB),
E. Troja (NASA/GSFC/ORAU) and B.-B. Zhang (PSU) report on behalf of
the Swift Team:

At 19:05:44 UT, the Swift Burst Alert Telescope (BAT) triggered and
located emission from the location of the flare star CC Eri (trigger=516027). 
Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 38.526, -43.825 which is 
  RA(J2000) = 02h 34m 06s
  Dec(J2000) = -43d 49' 30"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  As is usual for a 5-minute image trigger
there is no obvious variation in the immediately available lightcurve. 

The XRT began observing the field at 19:12:21.5 UT, 397.5 seconds after
the BAT trigger. XRT found a bright X-ray source located at RA, Dec
38.5956, -43.7978 which is equivalent to:
  RA(J2000)  = +02h 34m 22.94s
  Dec(J2000) = -43d 47' 52.1"
with an uncertainty of 4.8 arcseconds (radius, 90% containment). This
location is 205 arcseconds from the BAT onboard position. This position
is 5.4 arcseconds from that of a known X-ray source: the flare star, CC Eri. 
No event data are yet available to determine the column density using X-ray
spectroscopy. 

The initial flux in the 2.5 s image was 7.03e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 27 seconds with the White filter
starting 406 seconds after the BAT trigger. This source is very
bright, as expected for a flaring star with a quiescent magnitude
of V=8.8. More analysis will be required to provide an estimate of the
magnitude. The expected extinction corresponds to an E(B-V) of 0.02.