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GCN Circular 27211

Subject
LIGO/Virgo S200224ca: GRAWITA-Campo Imperatore observations.
Date
2020-02-25T21:25:28Z (4 years ago)
From
Fiore De Luise at INAF-Osservatorio Astro. d'Abruzzo <fiore.deluise@inaf.it>
F. De Luise, P. Tedesco, N. Napoleone (INAF- OAAb), A. Rossi (INAF-OAS), M.
Dolci, G. Valentini, M. Cantiello, A. Di Cianno, A. Valentini, L.P.
Pacinelli (INAF- OAAb), M. Fiaschi (MFC Elettronica), G. Greco (Univ.
Urbino), E. Cappellaro (INAF-OA Pd), P. D'Avanzo(INAF- OABr), A. Grado
(INAF-OA Capodimonte), and E. Brocato (INAF- OAAb and OAR), report on
behalf of GRAWITA:

We carried out observations of the LIGO/Virgo trigger GW S200224ca (GCN
Circ. #27184) using the INAF-OAAb 0.9m Schmidt Telescope of the INAF -
Astronomical Observatory of Abruzzo located at 2150 meters o.s.l. at Campo
Imperatore (Italy) and equipped with a 4096x4096 CCD covering a field of
view of 1.15��1.15 square degrees.

Due to weather conditions, only three pointings were made covering an area
of nearly 4 square degrees; a containment probability of ~ 8 % of the 50%
credible region was captured. The pointing sequence was generated using the
GWsky script (G. Greco, https://github.com/ggreco77/GWsky), starting from
the high probability region of the bayestar skymap and taking into account
the airmass and relative density of nearby galaxies at the distance of 1585
+/- 331 Mpc.

The total exposure time for each image was 3x180 sec. The observations were
taken with the r-Sloan band on  2020-02-24 starting at 23:47:37.0 UT, about
one hour after the GW detection (i.e. 2020-02-24 22:22:34.406 UTC). The
estimated limiting magnitude in r-Sloan is about 21.5 mag.

Hereafter the log of the observations.

| RA (J2000) | Dec (J2000) | UT time | filter | exposure time|

| 11:43:50.29 | -07:49:10 | 2020-02-24T23:47:37.0 | r-sloan  | 3x180 sec |

| 11:35:44.35 | -07:49:10 | 2020-02-25T00:04:09.6 | r-sloan  | 3x180 sec |

| 11:39:47.98 | -07:49:35 | 2020-02-25T00:20:44.8 | r-sloan  | 3x180 sec |

The analysis of images is ongoing.



--------------------------------------------
De Luise Fiore, PhD
INAF - Osservatorio Astronomico d'Abruzzo
Via Mentore Maggini, s.n.c.
64100 - TERAMO
Tel +39-0861-439712
Fax +39-0861-439740
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