POSSIBLE SUPERNOVA IN NGC 2536
Zhijian Xu(Nanjing,Jiangsu,China) and Xing Gao (Urumqi,Xinjiang,China), report the discovery of a possible supernova (mag approximately 16.3) on one 40-s survey image (limiting mag about 18.0) taken by Xing Gao in Xingming Observation Sky Survey(C42) around Oct.11.93917 UT. using an unfiltered CCD ( + Celestron C14 Schmidt-Cassegrain telescope D=356-mm @f/6.9 ). The new object approximately located at R.A.=08h 11m 16s.45 Decl.=+25°10’47”.4(equinox 2000.0). Which is about 6.0″ east and 1.7″ north of the center of the NGC 2536. Nothing is visible at this position on archival images taken on Mar.04(limiting mag 18.5),Mar.31(limiting mag 18.4), or on the DSS from Jan.10,1989(limiting mag about 19.9).
NET USNO-A2.0
XM68ZX C2014 10 11.93917 08 11 16.45 +25 10 47.4 16.3 V C42
All images can be seen from: http://www.xjltp.com/XOSS/XM68ZX/XM68ZX.htm
C42,Xingming Observatory,Mt. Nanshan. Observers Z.Xu,X.Gao,Measurers Z.Xu 0.36-m f/6.9 Schmidt-Cassegrain telescope and CCD.
Electronic Telegram No. 4010
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director: Daniel W. E. Green; Hoffman Lab 209; Harvard University;
20 Oxford St.; Cambridge, MA 02138; U.S.A.
e-mail: cbatiau@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network
SUPERNOVA 2014ds IN NGC 2536 = PSN J08111645+2510474
Z.-j. Xu (Nanjing, Jiangsu, China) and X. Gao (Urumqi, Xinjiang, China)
report the discovery of an apparent supernova (mag approximately 16.3) on one
40-s unfiltered CCD survey image (limiting mag about 18.0) taken by Gao in the
course of the Xingming Sky Survey around Oct. 11.939 UT using a 35.6-cm
Celestron C14 Schmidt-Cassegrain telescope at Mt. Nanshan. The new object is
approximately located at R.A. = 8h11m16s.45, Decl. = +25d10’47”.4 (equinox
2000.0), which is about 6″.0 east and 1″.7 north of the center of NGC 2536.
Nothing is visible at this position on archival images taken on Mar. 4
(limiting mag 18.5) and Mar. 31 (limiting mag 18.4) or on a Digitized Sky
Survey image from 1989 Jan. 10 (limiting mag about 19.9). Images were posted
at website URL http://www.xjltp.com/XOSS/XM68ZX/XM68ZX.htm. The variable was
designated PSN J08111645+2510474 when it was posted at the Central Bureau’s
TOCP webpage and is here designated SN 2014ds based on the spectroscopic
confirmation reported below. Additional CCD magnitudes for 2014ds: 2014
Oct. 12.376, 16.5 (J. Brimacombe, Cairns, Australia; remotely using a 51-cm
RCOS telescope + STXL-6303 camera at the New Mexico Skies observatory near
Mayhill, NM, U.S.A.; position end figures 16s.48, 46″.7; image posted at
website URL https://www.flickr.com/photos/43846774@N02/15338033047/); 12.93,
16.1 (Xu and Gao; position end figures 16s.47, 47″.3; image posted at URL
http://njzhijian.lamost.org/Supernova/PSNJ08111645+2510474-1012.jpg).
J.-j. Zhang, Yunnan Astronimical Observatory (YNAO); and X.-f. Wang,
Tsinghua University, report on an optical spectrogram (range 360-890 nm) of
PSN J08111645+2510474 = SN 2014ds that was obtained on Oct. 23.8 UT with the
2.4-m telescope (+ YFOSC) at the LiJiang Gaomeigu Station of YNAO. The
spectrum is consistent with a classification of type-IIb supernova, with Fe
II, Ca II, O I, and prominent H and He I features. A more narrow H-alpha
emission is found to sit on top of the broad component, which is perhaps due
to the interaction of supernova ejecta with the circumstellar materials.
Cross-correlation with a library of supernova spectra using the comparison
tool “Gelato” (Harutyunyan et al. 2008, A.Ap. 488, 383) shows that 2014ds has
a good match with SN 2008ax at a few days before maximum light. After
removing a recession velocity of 4142 km/s for the host galaxy, NGC 2536
(from de Vaucouleurs 1991, RC3.9), they measure a velocity of the H-alpha
absorption to be about 12600 km/s.
NOTE: These ‘Central Bureau Electronic Telegrams’ are sometimes
superseded by text appearing later in the printed IAU Circulars.
(C) Copyright 2014 CBAT
2014 October 30 (CBET 4010) Daniel W. E. Green