AstroNote 2020-217

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DRAFT
2020-11-05 21:25:42
Type: Object/s-Discovery/Classification
ZTF20acozryr/AT2020yxz: Zwicky Transient Facility discovery of a fast optical transient with no associated GRB
Authors: Michael Coughlin (UMN), Igor Andreoni (Caltech), Shreya Anand (Caltech), Erik Kool (OKC), Ana Sagues Carracedo (OKC), Anna Ho (UCB), Mansi Kasliwal (Caltech), Daniel Perley (LJMU), Tomas Ahumada (UMD) on behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations
Abstract:
We report the discovery of the fast optical transient ZTF20acozryr/AT2020yxz with the Zwicky Transient Facility (ZTF, Bellm et al. 2019, Graham et al. 2019) at coordinates (J2000,

ZTF20acozryr was found by the new “ZTF Realtime Search and Triggering” (ZTF-ReST) project, which aims at near real-time identification of compelling kilonova candidates in ZTF data using the methods described in Andreoni et al. (2020d), independently of gravitational-wave or gamma-ray triggers.

In the table below, we report photometry obtained on images processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC (Masci et al. 2019).

-----------------±-------±-----±-----

Date (UT) | mag | emag | band

-----------------±-------±-----±-----

2020-11-03 09:44 | > 19.4 |  -  | g

2020-11-04 08:47 | 19.5 | 0.2 | g

2020-11-04 10:28 | 19.2 | 0.1 | r

2020-11-05 06:43 | 20.2 | 0.3 | g

2020-11-05 08:13 | 19.9 | 0.2 | r

-----------------±-------±-----±-----

ZTF20acozryr is located off the Galactic plane, with Galactic latitude b_Gal = -41.5 deg. Deep Legacy Survey and Pan-STARRS1 images of the field do not reveal any permanent source at the transient location. There are two nearby sources reported in the Legacy Survey DR8 catalog. The first source (RA, Dec = 42.1845d, 12.1358d) has a separation of 5.24 arcsec (with a galaxy classification from DR8) from ZTF20acozryr and has reported magnitudes of g=24.38 mag, r=23.45 mag, and z=23.04 mag. The second source (RA, Dec = 42.1861d, 12.1395d) has a separation of 9.60 arcsec from ZTF20acozryr (with a point source classification from DR8) and has reported magnitudes of g=24.84 mag, r=24.07 mag, and z=23.49 mag.

There do not appear to be any publicly reported GRBs consistent with the sky location between the last non-detection and the first detection.

We encourage spectroscopic classification and multi-wavelength follow-up to discern the nature of ZTF20acozryr, a potential orphan afterglow candidate.

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 with Kowalski (Duev et al. 2019).

Show current TNS values
CatalogNameReported RAReported DECReported Obj-TypeReported RedshiftHost NameHost RedshiftRemarksTNS RATNS DECTNS Obj-TypeTNS Redshift
TNS2020yxz [ZTF20acozryr]02:48:44.312+12:08:14.1102:48:44.312+12:08:14.10