AstroNote 2026-221

ZTF26aazzexf / AT2026pwc was first detected by ZTF on 2026-06-06 as an alert with a detection of r = 20.238 AB mag and color of g-r = -0.216 mag. The source was identified by tdescore as a TDE candidate on this date. Forced photometry reveals detections as early as 2026-06-02. It was reported as a transient to TNS on 2026-06-22. The candidate was identified as a likely TDE due to its persistent blue optical color, nuclear location, and lack of AGN-like host signatures and was subsequently assigned for spectroscopic follow-up. We obtained an optical spectrum on 2026-07-09 with the Kast spectrograph on the 3-m Shane telescope at Lick Observatory, which revealed a blue, featureless continuum, possibly consistent with a TDE-featureless classification. Narrow host galaxy Fe II and Mg II absorption features confirmed the host redshift to be z = 0.526. The source is currently at peak, and the host redshift implies a peak luminosity of M_g = -23.283 mag, with peak color g-r = -0.349 mag. This absolute magnitude is on the luminous end of the featureless TDE distribution (see Hammerstein et al. 2023 or Yao et al. 2023), but may still be consistent with the class. Alternatively, the source may be consistent with the class of extreme nuclear transients (ENTs). Further follow-up is encouraged.

Based on observations obtained with the Samuel Oschin Telescope 48-inch and the 60-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under Award #2407588 and a partnership including Caltech, USA; Caltech/IPAC, USA; University of Maryland, USA; University of California, Berkeley, USA; University of Wisconsin at Milwaukee, USA; Cornell University, USA; Drexel University, USA; University of North Carolina at Chapel Hill, USA; Institute of Science and Technology, Austria; National Central University, Taiwan; Operations are conducted by Caltech's Optical Observatory (COO), Caltech/IPAC, and the University of Washington at Seattle, USA.