GCN Circular 36244

A. L. Piro, J. D. Simon (Carnegie), D. A. Coulter (STScI), M. R. Drout (Toronto), R. J. Foley, C. Rojas-Bravo (UC Santa Cruz), and C. D. Kilpatrick (Northwestern)

report on behalf of the Carnegie Gravitational wave ElectroMagnetic follow-up (CGEM) and the One-Meter Two-Hemisphere (1M2H) collaborations:

We have carried out a search for optical counterparts to the candidate gravitational wave event S240422ed (GCN 36236
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 ) using the 6.5m Magellan Clay telescope with the LDSS-3 imager.  We obtained a series of 120-second i-band images targeting galaxies coincident with the 3D localization of the event.  We performed a preliminary search of the data by comparing to archival Pan-STARRS images (Chambers et al., 2016), and found no obvious transient sources near the targeted galaxies.  However, we note that several images were deeper than the comparison images, precluding the exclusion of some faint sources detected in only the new images as transient sources.  The images have depths of ~21.5-22.5 mag.

We thank Marcelo Mora, Povilas Palunas, and the rest of the LCO staff for making these observations possible.

Below we provide a list of targeted galaxies and observation details.

RA          Dec          UT Start
07:57:41.8  -21:53:13.0  02:23:13
07:58:18.6  -20:40:09.0  02:27:51                         
07:58:40.1  -22:05:11.2  02:31:38                         
08:01:16.7  -18:22:40.8  02:35:44                         
08:02:23.4  -24:51:17.0  02:40:00                         
08:03:56.2  -22:45:18.4  02:43:47                         
08:04:28.2  -27:42:48.7  02:48:55                         
08:04:54.4  -28:09:41.9  02:54:24                         
08:05:26.0  -19:52:40.6  02:59:32                         
08:06:04.3  -22:27:12.0  03:04:27                         
08:10:04.0  -18:02:03.4  03:08:18                         
08:11:02.4  -17:01:51.3  03:13:31                         
08:12:16.7  -21:47:19.0  03:19:43                         
08:14:21.3  -15:28:23.3  03:23:25                         
08:14:21.8  -15:47:45.0  03:28:12                         
08:15:29.1  -15:44:02.8  03:31:46                         
07:52:28.3  -25:55:07.2  03:37:25                         
07:59:52.7  -19:47:48.0  03:40:36                         
08:00:19.3  -22:25:39.2  03:43:33                         
08:02:56.1  -17:38:41.8  03:46:27                         
08:03:05.4  -22:41:00.1  03:49:44                         
08:05:31.0  -22:40:00.2  03:52:28                         
08:09:15.2  -18:39:53.0  03:55:21                         
08:16:33.6  -20:39:43.8  03:58:10                         
08:18:00.6  -16:13:59.5  04:01:00                         
08:26:19.2  -20:50:51.5  04:03:40