Monday, February 22, 2010

Possible Nova in Scorpius

Following the posting on the Central Bureau's unconfirmed-objects webpage about a possible nova in Sco, on February 22.8, 2010 we performed some follow-up of this object remotely through through a 0.40-m, f/3.8 reflector + CCD, from GRAS Observatory (Moorook, Australia).

On our images we can confirm the presence of an optical counterpart with unfiltered CCD magnitude about 10.1 (UCAC2 Catalogue reference stars) at coordinates:

R.A. = 17 06 07.50, Decl.= -37 14 27.7
(equinox 2000.0; UCAC2 catalogue reference stars)

Our confirmation image:

This is an animation showing a comparison between our image and thearchive DSS plate:

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

UPDATE - February 24, 2010

According to Cbet No 2183 this transient in Scorpius has been discovered by Koichi Nishiyama and Fujio Kabashima (Japan) on two 40-s unfiltered CCD frames (limiting magnitude 12.7) taken around Feb. 20.857 UT using a 105-mm f/4 camera lens (+ SBIG STL6303E camera).

On Cbet 2186 (issued on February 23), K. Ayani (BAO) reported that a low-resolution spectrum (range 400-800 nm; resolution 0.5 nm at H-alpha) of the probable nova was obtained with the BAO 1-m telescope on Feb. 23.88 UT. This shows prominent H-alpha emission with P-Cyg absorption upon a red continuum. These features show that the new object is a "Fe II"-type nova.

The transient is officially NOVA SCORPII 2010.

by Ernesto Guido and Giovanni Sostero

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