Sunday, April 25, 2010

Possible Nova in Sagittarius

CBET circular No. 2261, issued on April 24, 2010, announces the discovery by K. Nishiyama & F. Kabashima (Japan) of a possible Milky Way nova (mag 11.2) in Sagittarius on two 40-s unfiltered CCD frames (limiting magnitude 13.2) taken around Apr. 23.782 UT using a 105-mm f/4 camera lens (+ SBIG STL6303E camera).

We performed some follow-up of this object remotely through a 0.25-m, f/3,4 reflector + CCD, from GRAS Observatory (near Mayhill, NM).

On our images taken on April 25.4, 2010 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude about 12.1 (UCAC2 Catalogue reference stars) at coordinates:

R.A. = 17 53 02.99, Decl.= -28 12 19.3

(equinox 2000.0; UCAC2 catalogue reference stars)

Our confirmation image:

This is an animation showing a comparison between our image and the archive DSS plate (IR Filter - 1980). Click on it for a bigger version.

Spectroscopic observations are required to confirm the real nature of this transient.

UPDATE - May 06, 2010

According to IUAC 9140, a spectra has been obtained at the Steward Observatory Bok 2.29-m telescope on Apr. 25.4 UT by L. A. Helton, T. Vonderharr, and C. E. Woodward and G. J. Schwarz. These observations confirm that this is a post-maximum classical nova. The spectra exhibit strong, broad H_alpha emission.

The permanent GCVS designation V5586 Sgr has been assigned to this nova.


by Ernesto Guido and Giovanni Sostero

No comments: