CBET circular No. 2735, issued on June 03, 2011, announces the discovery by John Seach (Australia) of a possible nova (mag 9.5) on three CCD images (limiting mag 11.0) taken on June 1.40 UT with a digital SLR camera (+ 50-mm-f.l. f/1.2 lens + orange filter).
We performed some follow-up of this object remotely with the GRAS RCOS 32-cm f/6.3 telescope at Officer, Australia. On our images taken on June 02.4, 2011 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude about 9.4 (USNO-B1.0 Catalogue reference stars) at coordinates:
R.A. = 16 55 09.46, Decl.= -38 38 04.5
(equinox 2000.0; USNO-B1.0 catalogue reference stars).
Our confirmation image (click for a bigger version):
Below you can see an animation showing a comparison between our confirming image and the archive POSS2/UKSTU plate (R Filter - 1995). Click on the thumbnail below for a bigger version:
CBET circular No. 2735 also reports that A. Arai, T. Kajikawa, and M. Nagashima, Kyoto Sangyo University, performed low-dispersion optical spectroscopic observations (range 400-750 nm; R about 600) of this transient on June 2.68 UT using the 1.3-m Araki telescope (+ LOSA/F2) under a hazy sky. The spectrum shows a broad H-alpha (FWZI about 4600 km/s) with an asymmetric profile and O I (777.4 nm) on a highly-reddened continuum. No visible He or Fe II lines exist in the spectrum. These features suggest that the object is a classical nova in outburst with high interstellar reddening.
(Credit: A. Arai, T. Kajikawa, and M. Nagashima)
by Ernesto Guido and Giovanni Sostero