AstroNote 2026-75

We report the discovery of AT2026fvx, discovered by the Large Array Survey Telescope (LAST; Ofek et al. 2023, PASP 135, 5001; Ben-Ami et al. 2023, PASP 135, 5002) at 19.64 +/- 0.09 mag (AB), coincident with NGC 4205 (17.5 Mpc).

The transient was first detected at MJD = 61116.942687 (2026-03-17 22:37 UTC) with a magnitude of 19.64 +/- 0.09 (AB), and spatial coincidence with the galaxy NGC 4205. The potential host is located at z = 0.0048 (17.5 Mpc, luminosity distance from NED), implying an absolute magnitude of about -12.0 (AB). The last non-detection by LAST was on MJD = 61116.07 (2026-03-17 01:53 UTC; 0.87 d before first detection) with a 5-sigma limiting magnitude of 20.9 (AB), and recent forced photometry indicates the transient is rising. The LAST photometry derived from difference images of the field is as follows

We rapidly triggered spectroscopy with the DeVeny spectrograph mounted on the 4.3m LDT telescope at Lowell Observatory. The reduced spectrum indicates this is a normal-looking SN Ia with Si II expansion velocity of about 17000 km/s. 

Followup observations are encouraged.

LAST is a survey telescope array operated by the Weizmann Astrophysical Observatory (https://www.weizmann.ac.il/wao/).

Lowell is a private, non-profit institution dedicated to astrophysical research and public appreciation of astronomy and operates the LDT in partnership with Boston University, the University of Maryland, the University of Toledo, Northern Arizona University and Yale University.