GCN Circular 21758

S.W.K. Emery (UCL-MSSL), A.A. Breeveld (UCL-MSSL), F.E. Marshall (NASA/GSFC),
S.R. Oates (Uni. of Warwick), N.P.M. Kuin (UCL-MSSL), S.D. Barthelmy (NASA/GSFC),
A.P. Beardmore (U. Leicester), D.N. Burrows (PSU), S. Campana (INAF-OAB),
S.B. Cenko (NASA/GSFC), G. Cusumano(INAF-IASF PA), A. D'Ai (INAF-IASFPA),
P. D'Avanzo (INAF-OAB), V.D'Elia(ASDC), P.A. Evans (U. Leicester),
P. Giommi (ASI), C. Gronwall (PSU), J.A. Kennea (PSU), H.A. Krimm (CRESST/GSFC/USRA),
A.Y. Lien (GSFC/UMBC), A. Melandri (INAF-OAB), J.A. Nousek (PSU), P.T. O'Brien (U. Leicester),
J.P. Osborne (U. Leicester), C. Pagani (U. Leicester), K.L. Page (U.Leicester),
D.M. Palmer (LANL), M. Perri (ASDC), J.L. Racusin (NASA/GSFC), T. Sakamoto (AGU),
B. Sbarufatti (INAF-OAB/PSU), M.H. Siegel (PSU), G. Tagliaferri (INAF-OAB),
A. Tohuvavohu (PSU), E. Troja (NASA/GSFC/UMCP)
report on behalf of the Swift team:

Swift has performed follow-up ToO observations of the optical transient SwiftJ014008.5+343403.6,
reported in Emery et al. (GCN 21733
Not found
 
 
). We obtained 4 ks of data from 278 ks to 341 ks after the
LVC trigger. This source has faded and is no longer detected in any filter. Earlier MASTER observations
did not detect this source, see Lipunov et al. (GCN 21749
Not found
 
 
). Other observatories have also not detected
the source (Tomasella et al. (GCN 21745
Not found
 
 
); Pozanenko et al. (GCN 21754
Not found
 
 
); Copperwheat et al. (GCN 21755
Not found
 
 
);
Jonker et al. (GCN 21756
Not found
 
 
); Butler et al. (GCN 21757
Not found
 
 
)).

We obtain preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373):

Filter  Start time     Stop time   Exposure(s)   Magnitude(Vega)
   v     T0+278 ks     T0+341 ks      372            >20.1     
   b     T0+277 ks     T0+340 ks      372            >21.1     
   u     T0+277 ks     T0+340 ks      372            >20.7     
uvw1     T0+276 ks     T0+340 ks      745            >21.0     
uvm2     T0+278 ks     T0+341 ks      514            >20.5     
uvw2     T0+277 ks     T0+340 ks     1491            >21.6     

The magnitudes are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the source
(Schlegel et al. 1998).

Further Swift observations are planned.