ZTF21aahifke/AT2021clk: ZTF discovery of an optical fast transient
Abstract
We report the discovery of the fast optical transient ZTF21aahifke/AT2021clk with the Zwicky Transient Facility (ZTF, Bellm et al. 2019, Graham et al. 2019), as part of the "ZTFReST" project aiming at real-time kilonova and fast transient discovery. ZTF21aahifke was first detected on 2021-02-06 03:14 UT, hereafter labelled T_det. It faded by ~0.9 mag in r-band in the first 24 hours since T_det. The transient was last detected by ZTF on 2021-02-07 03:58 UT at r = 20.9 +- 0.2 mag. Upper limits constrain the transient onset time to be within ~1 day from T_det. The color of the transient appears to be red, with g-r~0.3 (un-corrected) at T_det. The Galactic extinction on the line of sight is E(B-V)=0.12 mag. ZTF21aahifke is located at Galactic latitude b_Gal = -20.1 deg. The nature of ZTF21aahifke remains uncertain and we cannot exclude the possibility that it is the afterglow of an un-triggered (or off-axis) GRB, or Galactic in origin. Follow-up observations are encouraged.
- Publication:
-
Transient Name Server AstroNote
- Pub Date:
- February 2021
- Bibcode:
- 2021TNSAN..58....1A
- Keywords:
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- Transient;
- Optical;
- ZTF21aahifke;
- 2021clk;
- AT2021clk;
- AT 2021clk