PSN J02283286+2017077 2015 07 10.7439* 02 28 32.86 +20 17 07.7 17.3 U 9W 6N N938 I 0
2015 07 10.744
Discovered by K. Itagaki, Yamagata, Japan, on an unfiltered CCD frame using 0.60-m f/5.7 reflector under the limiting magnitude= 19.0. PSN was confirmed on two followed-up frames after the discovery. His discovery image was posted at http://k-itagaki.jp/images/938.jpg.
2015 07 12.14274
Mag.=16.9U, position end figures 32s.93, 07".8 (reference stars from UCAC-4), on three stacked 120-s frames (limit mag.= 19.0) using 0.32-m f/8.0 astrograph + SBIG-STXL-6303E camera at AstroCamp Observatory. Nerpio, Spain. Observer T. Yusa, Osaki, Japan. An image was posted at URL http://space.geocities.jp/yusastar77/supernova/PSNinN938_150712.htm
2015 07 12.761
Mag.= 16.7, position end figures 32s.84, 08".3 observed by K. Itagaki, Yamagata, Japan, using 0.60-m f/5.7 reflector + unfiltered CCD.
2015 07 13.03941
This transient was observed on 2015 07 13.03941 by G. Masi, remotely using the 17"-f/6.8 robotic unit part of the Virtual Telescope Project facility, at Bellatrix Astronomical Observatory in Ceccano, Italy. 120-seconds exposures, unfiltered, show the source at mag. 16.2 (R mags for the reference stars from UCAC-4). We also performed astrometry, getting the following end figures: 32.85; 08.0 (J2000.0, mean residuals of 0.1" on both axes).
2015 07 26.8
K. Ayani, Bisei Astronomical Observatory (BAO), Ibara, Okayama, Japan, obtained a low-resolution spectrogram (range 400-675 nm; resolution 0.6 nm at H-alpha) of this PSN with the BAO 1.01-m telescope on July 26.8 UT. The spectrum is that of a normal type-Ia supernova around maximum. Cross-correlation with a library of supernova spectra using the "SuperNova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows that this possible supernova matches best with SN 1995E at 3.9 days past maximum. Assuming the heliocentric velocity for NGC 938 of 4118 km/s (Caldwell et al. 2003, A.J. 125, 2891; via NED), the blueshift of the Si II 635.5-nm absorption is about 10500 km/s. Our spectrum is posted at http://www.bao.city.ibara.okayama.jp/astro/2015/psn/PSN_J02283286+2017077_Jul26.png.