Saturday, February 20, 2010

Nova Ophiuchi 2010 (No. 2)

CBET circular No. 2176, issued on February 19, 2010, announces the discovery by Hideo Nishimura (Japan) of a possible nova (mag 9.4) in Ophiuchus on two 13-s frames taken on Feb. 18.845 UT using a Minolta 120-mm f/3.5 lens and a Canon EOS 5D Digital camera.

On our images taken on February 20.5, 2010 through a 0.25-m, f/3,4 reflector +CCD, from GRAS Observatory (near Mayhill, NM), we can confirm the presence of an optical counterpart with unfiltered CCD magnitude about 9.4 (UCAC2 Catalogue reference stars) at coordinates:

R.A. = 17 26 32.15, Decl.= -28 49 41.8
(equinox 2000.0; UCAC2 catalogue reference stars).

According to Nishimura nothing is visible at this position on his survey frames taken during each month in the span 2009 Feb.-Oct. 15 and on 2010 Feb. 2, 4, 5, 7, and 13.84 UT (limiting mag 11).

Our confirmation image:

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

Please click here for a bigger version:

On Vsnet mailing list Imamura-san (Okayama U. of Sci.) and Fujii-san have reported spectra of this object confirming it as a nova:

According to Taichi Kato "Halpha emission was accompanied by a P Cyg absorption (blue-shifted by1000 km/s). Balmer emission lines with P Cyg profiles (700 km/s for Halpha) and Fe II lines were visible."

by Ernesto Guido & Giovanni Sostero

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