TITLE: GCN CIRCULAR NUMBER: 36367 SUBJECT: LIGO/Virgo/KAGRA S240422ed: Host redshifts of AT2024hfq, AT2024hfu, and AT2024hmo from DBSP DATE: 24/05/02 00:00:10 GMT FROM: Tomas Ahumada Mena at Caltech tahumada@caltech.edu

Tomas Ahumada (Caltech), Sam Rose (Caltech), Kaustav Das (Caltech), Mansi Kasliwal (Caltech), Igor Andreoni (UMD) report on behalf of the Zwicky Transient Facility (ZTF) collaboration:

We observed the candidates AT2024hfq, AT2024hfu, and AT2024hmo (GCN 36298, GCN 36303) with the Double Beam Spectrograph (DBSP) mounted on the Palomar 200-in telescope on 2024-05-01 (UTC), using a setup with a red grating of 316/7500, a blue grating of 600/400, a D55 dichroic, and a slitmask of 1.5". The data were reduced using a custom DBSP pipeline relying on Pypeit (Prochaska et al. 2019, Roberson et al. 2021).

We derived the redshifts from the H-alpha emission line of either the transient or the potential host. We conclude that these transients are unrelated to the event S240422ed, as all these are beyond 5-sigma of the median distance provided by the LVK skymap (GCN 36240).

AT name | redshift | notes --------------------------- AT2024hfq | 0.148 | AT2024hfu | 0.126 | host redshift AT2024hmo | 0.086 |

We thank the Palomar observatory staff for making these observations possible.

ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IITB, India; IIA, India; LJMU, UK; TTU, USA; SDSU, USA and USyd, Australia. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert database searches are done by AMPEL (Nordin et al. 2019) and Kowalski (Duev et al. 2019). GROWTH India telescope is located at the Indian Astronomical Observatory (Hanle), operated by the Indian Institute of Astrophysics (IIA). GROWTH-India project is supported by SERB and administered by IUSSTF, under grant number IUSSTF/PIRE Program/GROWTH/2015-16 and IUCAA.

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