ngc6643sn.jpgT. Kryachko (Astrotel obs., KSU) and S. Korotkiy (Ka-Dar obs., Moscow) confirmed possible supernova at coordinates: R.A.=18h 19m 51.88s +/-0.2″, DEC=+74d 33′ 54.7″ +/-0.3″ (equinox 2000.0, reduction with reference to USNO-A2.0), which is about 21″.6 east and 11″.5 south of center of the galaxy NGC 6643 on one  image with 300 sec exposure (limiting Red-filter mag 20.0) obtained on Dec. 19.7225UT with the Takahashi FRC-300 (D=300mm, F=2330mm) + CCD Apogee Alta U9000 at Kazan State University Astrotel observatory (Karachay-Cherkessia, Russia, MPCCOD: 114).  We have measured V magnitude (with R zero-point) of the supernova 15.4V. Nothing is visible at this position on a Palomar Sky Survey (POSS-II Red) obtained 1993-07-23 (via the Digitized Sky Survey; limiting mag 20.5). In MPChecker no asteroids.