TITLE:   GCN CIRCULAR
NUMBER:  15753
SUBJECT: GRB 140118A/MAXI J1421-613: Skynet PROMPT/R-COP observations
DATE:    14/01/18 18:24:52 GMT
FROM:    Adam S. Trotter at UNC-Chapel Hill/PROMPT/Skynet  <atrotter@physics.unc.edu>

A. Trotter, D. Reichart, A. Verveer, T. Spuck, A. LaCluyze, J. Haislip, 
A. Foster, N. Frank, K. Ivarsen, J. Moore, M. Nysewander, R. Beauchemin, 
T. Berger, M. Carroll, H. T. Cromartie, R. Egger, M. Hinckle, A. 
Ireland, M. Maples, L. Scott, and J. A. Crain report:

Skynet observed the Swift-BAT localization of GRB 140118A/transient 
source MAXI J1421-613 (Baumgartner et al., GCN 15749, Swift trigger 
584155) with one 24" and four 14" telescopes of the PROMPT array at 
Cerro Tololo, Chile, with two 14" telescopes of the PROMPT array at 
Siding Springs, Australia, and with the 14-inch R-COP telescope at Perth 
Observatory, Australia.  Observations began 86s after the trigger, 
simultaneously in the BVRI bands. We detect no uncatalogued optical 
source in the refined Swift-BAT error circle (Lien et al., GCN 15750). 
In stacks of exposures, we obtain the following upper limits:
Mean Time   Band    Limit
10.8m       I       >19.6
14.9m       R       >19.1
11.7m       V       >19.8
14.9m       B       >19.1
6.94h       I       >17.3
7.10h       R       >16.9
6.02h       V       >20.4
6.04h       B       >20.4

Photometry is calibrated to five APASS-DR7 stars in the field, and has 
not been corrected for the extremely significant Galactic foreground 
extinction corresponding to E(B-V)=10.5 (Schlegel et al. 1998).

No further Skynet observations are scheduled.