AT2026stb is a Galactic nova in Scutum
ATel #17886; Laura Chomiuk, Jay Strader (Michigan State University)
on 12 Jul 2026; 15:10 UT
Credential Certification: Laura Chomiuk (chomiuk@pa.msu.edu)
We report optical spectroscopy with the SOAR 4.1m telescope confirming that AT2026stb is a Galactic nova. AT2026stb was discovered by ZTF is located at RA=18:31:15.618, Dec=-05:34:31.92 (Galactic latitude b=+1.9) on 2026 July 8 at g = 17.1, r =15.1mag, and was flagged by DCAP as a nova candidate (DCAP269). In the most recent ZTF observation from 2026 July 12, AT2026stb sits at g = 15.96, r =14.04, i = 12.97 mag, implying that the optical light curve is still rising.
The first reported spectroscopy is listed in TNS by Claudio Balcon on 2026 July 12 01:38 (UT), showing a reddened continuum with bright H-alpha.
The SOAR/Goodman spectrum, obtained via AEON on 2026 July 12 04:21 (UT), covers the region 5000 to 9000 A, with prominent H-alpha, O I, and He I lines. The H alpha line does not show P Cygni absorption, and its emission profile has FWHM = 1200 km/s. This spectrum is consistent with a reddened classical nova.
There are no cataloged optical/IR sources within 2 arcseconds in Vizier, so AT2026stb is not associated with a progenitor in pre-explosion imaging, consistent with significant extinction.
