PNV J18110375-2717276 2012 04 23.689 * 18 11 03.75 -27 17 27.6 12.5 U Sgr 2 9
2011 04 12.784
Mag.= 10.9. Discovered by T. Kojima, Gunma-ken, Japan, using Canon EOS40D + 150-mm f/2.8 lens who found many past images of this star on his past patrol frames. Star was the most brighten (mag.= 10s) between 2011 April - October and the recent magnitude is 12.5. Although this star is not cataloged on AAVSO and ASAS3 but there is a bright star on 2MASS catalog. Kojima reports the past magnitudes on his patrol frames: 2011 Apr. 12.784 UT, 10.9; Apr. 28.722, 10.7; July 05.518, 10.6; Sept.23.425, 11.2; Oct. 16.394, 10.8; Oct. 29.391, 11.3; 2012 Feb. 27.815, 12.5; Apr. 23.689, 12.5 under limiting mag.= 13-14.
2011 02 19.835
Mag.= 11.0 observed by K. Itagaki, Yamagata, Japan, using 0.21-m f/3.0 reflector + CCD who found this star was visible on his many frames as a star of mag.= 11 - 12. But nothing is visible on a frame taken on 2008 June 10 UT (limiting mag.= 14.4) using same instrument. H. Kaneda, Sapporo, Japan, has measured the position end figures 03s.73, 28".7. Also he measured a frame taken on 2012 Apr. 14.746, mag.= 12.3, 03s.73, 29".1.
2012 05 12.6258
I did multicolor photometry of this nova candidate with 20cm Schmidt-Cassegrain telescope + Apogee E47 CCD camera at Tsukuba, Japan. Photometric results were V=12.97, Rc=12.18, Ic=11.81. V-I color is not so red such as red variables like mira type. Spectroscopic confirmation are need to reveal nature of this star. Image available at http://meineko.sakura.ne.jp/ccd/PNV_J18110375-2717276.jpg Seiichiro Kiyota, Tsukuba, Japan.
2012 05 13.715
Mag.= 12.3 observed by Itagaki and measured by Kaneda who gives the position end figures 03s.70, 29".1 on two Itagaki's frames using 0.50-m f/5.0 reflector + unfiltered CCD. See an image at http://www.k-itagaki.jp/sgr-pnv.jpg.
2012 05 12.715
K. Ayani (Bisei Astronomical Observatory) reports that M. Fujii at Fujii Kurosaki Observatory (hereafter FKO), Kurashiki-shi, Okayama, Japan, obtained low-resolution spectra of this possible nova with the spectrograph at FKO. Fujii reports that the spectra show evolved [OIII] lines and look like those of a nova long after burst. His spectra can be seen at http://otobs.org/FBO/novae/pnv_j18110375_20120512.gif .
2012 05 18.737
K. Ayani (Bisei Astronomical Observatory) reports that M. Fujii (Fujii Kurosaki Observatory) obtained low-resolution spectra of this possible nova again. His new spectra can be seen at http://otobs.org/FBO/novae/pnv_j18110375_20120518.gif .
2012 05 23.7
K. Ayani and S. Maeno at Bisei Astronomical Observatory (hereafter BAO), Ibara-shi, Okayama, Japan, obtained low-resolution spectra of this possible nova with BAO 1-m telescope. The spectra resemble that of Nova Oph 1991 No. 1 (V2264 Oph) taken on June 12, 1991, (more than 2 months after maximum) which was appeared in a paper by Williams et al. (1994; ApJS 90, 297). Our spectrum can be seen at http://www.bao.city.ibara.okayama.jp/astro/2012/nova/pnv/PNV_J18110375-2717276_May23a.png and http://www.bao.city.ibara.okayama.jp/astro/2012/nova/pnv/PNV_J18110375-2717276_May23b.png .