Thursday, October 1, 2015


Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Sgr (TOCP Designation: PNV J18033275-2816054) we performed some follow-up of this object remotely through a 0.43-m f/6.8 astrograph + CCD) of  iTelescope network (MPC Code  Q62 - Siding Spring).

On our images taken on September 28.4, 2015 we can confirm the presence of an optical counterpart with R-CCD magnitude 9.5 at coordinates:

R.A. = 18 03 32.77, Decl.= -28 16 05.3

(equinox 2000.0; UCAC4 catalogue reference stars).

Our annotated confirmation image. Click on it for a bigger version:

An animation showing a comparison between my confirmation image and the archive POSS1 Blue plate (1958-04-18). Click on the thumbnail below for a bigger version:

According to CBET nr. 4145, issued on 2015, September 30, , PNV J18033275-2816054 is now NOVA SAGITTARII 2015 No. 3. This nova has been discovered K. Itagaki (Teppo-cho,Yamagata, Japan) on an unfiltered CCD frame taken on Sept. 27.429 UT using a 180-mm-focal-length camera lens.

A spectrogram (resolution about 500 at H-beta) taken of PNV J18033275-2816054 by M. Fujii (Kurashiki, Okayama, Japan) with a 0.4-m telescope on Sept. 27.487 UT shows Balmer emission lines, with the H-beta line having a P-Cyg profile that indicates an expansion velocity of about 1100 km/s.  Emission lines of Fe II (37), (42), and (49) also have P-Cyg profiles.  The Na D absorption is remarkable. (see image below).

Credit: M. Fujii

by Ernesto Guido

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