We report AT2026ngr as a candidate strongly gravitationally lensed supernova identified in data from the Zwicky Transient Facility (ZTF). The transient, designated ZTF26aaxhpdm, was first detected on 2026 May 15 (UT) at approximately r = 20.9 mag and i = 19.9 mag, and was reported to TNS on 2026 May 21 (UT). Subsequent detections show the source continuing to brighten, currently reaching i = 19.3 mag, while maintaining consistently red colors (r − i ≈ 0.6 mag).
The transient is offset by approximately 0.5″ from a luminous red galaxy (LRG) with a DESI spectroscopic redshift of z = 0.2721. Assuming association with the LRG, the transient has an approximate absolute i-band magnitude of ≈ −21.5 mag.
Legacy Survey DR10 imaging (attached figure) shows the LRG (red ellipse) together with a blended nearby galaxy (blue ellipse), which may correspond either to a foreground/background galaxy or to a lensed host system associated with the transient.
No obvious prior variability is detected at the transient position in historical ZTF or ATLAS imaging.
Given the potential importance of this system for studies of supernova physics and time-delay cosmography, we strongly encourage rapid spectroscopic and high-resolution imaging follow-up to determine the transient type and redshift.
We thank the ZTF collaboration and follow-up observers for their contributions.
| Catalog | Name | Reported RA | Reported DEC | Reported Obj-Type | Reported Redshift | Host Name | Host Redshift | Remarks | TNS RA | TNS DEC | TNS Obj-Type | TNS Redshift |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TNS | 2026ngr [ZTF26aaxhpdm] | 13:58:24.302 | -03:02:49.29 | 13:58:24.302 | -03:02:49.29 | SN Ia | 0.95 |
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