Possible new object showing a featureless blue spectrum

ATel #17646; Masaki Tsuboi (Association of Hiroshima Astronomers), Tatsuya Nakaoka (Hiroshima Univ.), Koji S. Kawabata (Hiroshima Univ.)
on 5 Feb 2026; 20:11 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Koji Kawabata (kawabtkj@hiroshima-u.ac.jp)

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We report the discovery of a new transient exhibiting a featureless blue spectrum. Its equatorial coordinate (J2000) is RA = 07:30:08.5 and Dec = +24:30:05. Our imaging observations with a 0.35-m reflector (F/4.6) equipped with an SBIG ST-2000XM (no filter) yielded the following approximate V-band magnitudes: >17.8 on Jan 17.49 (UT), 15.8 on Jan 30.40, 16.0 on Feb 2.43, 16.1 on Feb 3.42, 16.4 on Feb 4.48, and 16.5 on Feb 5.42. An optical spectrum obtained with HOWPol on the 1.5-m Kanata Telescope at Higashi-Hiroshima Observatory on Feb 3.4 shows a featureless blue continuum, consistent with a luminous fast blue optical transient (LFBOT) near its peak brightness. If the transient is associated with the nearby galaxy NGC 2398, its absolute magnitude on Jan 30.40 should be M_V~-20.0 (assuming m-M=35.6 and A_V=0.17; NED database). Follow-up observation is encouraged.