TITLE:   GCN CIRCULAR
NUMBER:  20445
SUBJECT: LIGO/Virgo G268556: TZAC TAROT network observations with TRE/TCA/TCH
DATE:    17/01/13 10:10:50 GMT
FROM:    Michel Boer at CESR-CNRS  <michel.boer@unice.fr>

M. Boer, R. Laugier, K. Noysena (ARTEMIS - CNRS/UCA/OCA), A. Klotz (IRAP 
- CNRS/UPS) report on behalf of the TZAC collaboration.

The TAROT network of telescopes has observed part of the error box of 
the GW trigger G268556 (Shawman et al., GCN 20364). The observations 
took place at TCA (TAROT OCA Calern observatory, France), TCH (TAROT 
Chile, ESO La Silla Observatory), and TRE (TAROT Les Makes Observatory, 
La Réunion Island, France) during their respective nights of January 5-6 
and 6-7, 2017. The field of view of TCA and TCH is 1.86° (square), and 
4.2° for TRE. 4 fields have been observed by TCA, 5 for TCH and 9 for 
TRE, resulting in a total of 175 sq. deg. explored in the error box. The 
source ATLAS17aeu (Tony et al., GCN 20382) was not included in our 
fields. The exposures lasted 120s with no filter, resulting in 
approximate limiting magnitude of R < 17 for TCA and TCH (depending on 
the conditions and Moon) and 16 for TRE. The list of the fields is given 
below.

We have checked the TCA and TCH fields and found no new candidate 
astrophysical transient sources. Analysis is still underway for TRE.

List of field centers (J2000):

TCA (1.86° x 1.86°)

#0

	

08h51m11s

	

+47d58m55s

#1

	

08h43m27s

	

+46d02m16s

#2

	

08h56m47s

	

+49d53m15s

#3

	

09h05m31s

	

+52d01m07s

TCH (1.86° x 1.86°)

#0

	

23h49m18s

	

-36d03m12s

#1

	

23h58m29s

	

-37d19m07s

#2

	

00h08m10s

	

-38d22m09s

#3

	

00h17m47s

	

-39d19m59s

#4

	

23h34m38s

	

-33d52m51s


TRE (4.2° x 4.2°)

0

	

23h44m45s

	

-35d28m08s

1

	

00h02m19s

	

-37d20m19s

2

	

00h22m48s

	

-39d26m19s

3

	

00h44m36s

	

-42d01m15s

4

	

01h07m43s

	

-43d40m09s

5

	

23h31m33s

	

-32d11m14s

6

	

23h18m49s

	

-28d00m31s

7

	

23h03m54s

	

-24d30m28s

8

	

22h52m18s

	

-20d50m51s