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GCN Circular 27211

LIGO/Virgo S200224ca: GRAWITA-Campo Imperatore observations.
2020-02-25T21:25:28Z (4 years ago)
Fiore De Luise at INAF-Osservatorio Astro. d'Abruzzo <>
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,, 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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