[AAVSO-HEN] GRB 080514B: second epoch Swift XRT data confirms the X-ray afterglow

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
For an archive and more information on circulars visit:
http://lheawww.gsfc.nasa.gov/docs/gamcosray/legr/bacodine/gcn3_archive.html

TITLE:   GCN CIRCULAR
NUMBER:  7750
SUBJECT: GRB 080514B: second epoch Swift XRT data confirms the X-ray afterglow
DATE:    08/05/19 10:23:12 GMT
FROM:    Paolo Esposito at INAF-IASF,Milano  <paoloesp at iasf-milano.inaf.it>

P. Esposito, A. De Luca, A. Tiengo, G. Vianello (INAF-IASF MI),
K.L. Page (U. Leicester) report:

GRB 080514B was discovered by the SuperAGILE detector on May 
14th, at 09:55:56 UT (Rapisarda et al., GCN Circ. 7715) and 
possibly detected at energies E>50 MeV in AGILE GRID data 
(Giuliani et al., GCN Circ. 7716). 

The first Swift/XRT observation was performed on May 14th at 
20:12, starting about 37 ks after the GRB trigger (Page et al., 
GCN Circ. 7723). A likely afterglow candidate was found, with a 
flux decay described by a power-law (slope: 1.5+/-1.0; GCN Circ. 
7723). The spectrum was modelled with an absorbed ( 1.2x10^21 cm^-2) 
power-law, with photon index = 2.06 (GCN Circ. 7723).

Swift/XRT observed again the field of GRB 080514B on May 16th at 
20:13, about 58 hours after the trigger. 6 ks of data in Photon 
Counting mode were collected in three consecutive orbits, spanning 
5 hours.

The candidate X-ray afterglow (GCN Circ. 7723) is significantly 
detected with a 0.3-10 keV observed flux of (1.9+/-0.8)x10^-13 
erg cm^-2 s^-1 (assuming the spectrum of Circ. 7723). 

The new XRT data confirm the fading trend reported in (GCN Circ. 
7723) and better constrain the decay slope at 1.6 +0.3/-0.2. 

We thank the Swift PI, N. Gehrels, for approval of this TOO, and 
the the Swift team (in particular the duty scientists and science 
planners) for performing it.