[vsnet-grb-info 19303] GRB 170405A: Etelman observatory optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20998
SUBJECT: GRB 170405A: Etelman observatory optical observations
DATE:    17/04/06 19:41:45 GMT
FROM:    Bruce Gendre at UVI  <bruce.gendre at gmail.com>

B. Gendre (UVI), N. Orange (OrangeWave Innovative Science, LLC), D.
Morris (UVI), A. Cucchiara (UVI), D. Drost (UVI), T. Giblin (USAF
Academy), J. Hakkila (College of Charleston), A. Klotz (IRAP), J. Neff
(NSF), D. Smith (UVI), J. Staff (UVI), P. Thierry (Auragne Observatory),
R. Watlington (UVI), and L. Wentlent (UVI) report:

We observed the field of GRB 170405A (Troja et al, GCN 20984;
Hui & Meegan, GCN 20986; Vianello & Kocevski, GCN 20987) with the
0.5m Virgin Island Robotic Telescope (VIRT) on February the 6th,
starting at 6:15 UT (11.6 hours after the trigger). We
performed a series of exposures in the clear filter. The weather
conditions were good during the observations.

We co-added the exposures taken between 6h15UT (t0+11.6h) and
7h29UT (t0+12.8h), for a total exposure of 3510s. At the position of the 
optical afterglow reported by Malesani et al. (GCN 20988), we do not 
detect any optical emission, with an upper limit of R = 21.3 (Johnson 
system) estimated from nearby NOMAD1 stars.

Magnitudes have not been corrected for Galactic extinction.
The VIRT is still in its commissioning phase.

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