Monday, April 26, 2010

Possible Nova in Scorpius

CBET circular No. 2262, issued on April 26, 2010, announces the discovery by K. Nishiyama & F. Kabashima (Japan) of another possible nova (mag 8.6) on two 40-s unfiltered CCD frames (limiting magnitude 13.1) taken around Apr. 25.788 UT using a 105-mm f/4 camera lens (+ SBIG STL6303E camera). The same CBET reports indipendent discovery by H. Nishimura & T. Kojima.

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 26.4, 2010 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude about 8.2 (UCAC2 Catalogue reference stars) at coordinates:

R.A. = 16 55 13.17, Decl.= -38 03 47.8

(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 (R Filter - 1995). Click on it for a bigger version.

UPDATE - MAY 06, 2010

According to IAUC circular No. 9142, a low-dispersion spectrum (range 420-850 nm, resolution about 500) of this object, taken by K. Kinugasa, H. Takahashi, and O. Hashimoto on Apr. 29.745 UT with the GAO 1.5-m telescope (+ GLOWS), shows broad (FWHM about 4000 km/s) Balmer and O I (777.4-, 822.7-, and 844.6-nm) emission lines. The features indicate that the object is a He/N nova in a declining phase.

The permanent GCVS designation V1311 Sco has been assigned to this nova.


by Ernesto Guido and Giovanni Sostero

No comments: