Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 27075

LIGO/Virgo S200213t: P200 Spectroscopy of ZTF20aanakcd/AT2020cmr
2020-02-15T06:23:56Z (4 years ago)
Igor Andreoni at Caltech <>
Igor Andreoni (Caltech), Kishalay De (Caltech), Mansi Kasliwal (Caltech), Yang Huang (Yunnan Univ.), Xiaowei Liu (Yunnan Univ.)
On behalf of the GROWTH collaboration

On 2020-02-15 03:30 UT, we used the Double Beam Spectrograph (Oke & Gunn 1982) on the Palomar 200-inch telescope to observe ZTF20aanakcd/AT2020cmr (Reusch et al., GCN #27068), a transient discovered with the Zwicky Transient Facility (Graham et al., 2019; Bellm et al., 2019) during the follow-up of the binary neutron star merger candidate S200213t (LVC, GCN #2704).

The optical spectrum shows intermediate width Balmer emission features consistent with a Type IIn supernova at z=0.077. We also confirmed that the redshift of the transient is consistent with the host galaxy redshift, extracted from the same observations, based on the analysis of Balmer and [S II] lines.  We conclude that ZTF20aanakcd/AT2020cmr is unrelated to S200213t.
Looking for U.S. government information and services? Visit