Possible Nova in Sgr

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Sgr (TOCP Designation: PNV J17452791-2305213) we performed some follow-up of this object remotely through 0.25-m f/3.4 reflector + CCD from MPC code H06 (Mayhill station, NM).

On our images taken on April 22.4, 2012 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude 9.1  at coordinates:

R.A. = 17 45 28.02, Decl.= -23 05 23.2

(equinox 2000.0; USNO-B1.0 catalogue reference stars).

According to VIZIER there is a 16.21 R1-magnitude star at 0.237 arcseconds from the transient position (USNO-B1.0 0669-0621295).

Our confirmation image (click on it for a bigger version):

An animation showing a comparison between our confirmation image and the archive POSS2/UKSTU plate (R Filter - 1996). Click on the thumbnail for a bigger version:

UPDATE - April 25, 2012

According to Cbet 3089, spectra obtained by Christian Buil and Kazuyoshi Imamura, Okayama University of Science (OUS) shows emission lines of H-alpha. The transient appears to be a classical nova. This nova, designated NOVA SAGITTARII 2012, has been discovered by Stanislav Korotkiy and Kirill Sokolovsky, on three 30-s unfiltered CCD images (limiting magnitude about 14.0) obtained on Apr. 21.011 UT with a wide-field survey camera (+ 135-mm-f.l. f/2 telephoto lens + ST8300M camera) at Ka-Dar Observatory's TAU Station near Nizhny Arkhyz, Russia.


by Ernesto Guido, Nick Howes & Giovanni Sostero

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.

V5586 SAGITTARII = NOVA SAGITTARII 2010 No. 2

by Ernesto Guido and Giovanni Sostero

Possible Nova in Sagittarius

CBET circular No. 2140, issued on January 23, 2010, announces the discovery by John Seach (NSW, Australia) of a possible nova in Sagittarius (mag 8.5) on three 6-s CCD exposures (limiting mag 11) obtained on Jan. 20.22 UT with a Nikon D300 camera (+ 50-mm f/1.4 lens + orange filter).

The object is located at (position provided by S. Kiyota):

R.A. = 18h07m26s.79, Decl. -29d00'42".8 (equinox 2000.0)

Follow-up observers on CBET are noting that nothing is visible at this position on a DSS image.

UPDATE - January, 24

On CBET circular No. 2142, H. Maehara (Kyoto University) reports that a low-resolution spectrogram (range 400-800 nm) of the possible nova was obtained on Jan. 23.887 UT with the 25-cm telescope of the Kwasan Observatory. The spectrum shows H_alpha, H_beta, and Fe II emission lines. These features suggest that this object is a "Fe II"-class nova.

This transient has been designated  V5585 SAGITTARII = NOVA SAGITTARII 2010

(Credit: H. Maehara)

by Ernesto Guido

NOVA SAGITTARII 2009 No. 3

Cbet No. 1899 issued on 2009, August 07th announces the discovery by K. Nishiyama and F. Kabashima of a possible nova (magnitude at discovery 7.7) in Sagittarius on two 60-s frames on Aug. 6.494 and 6.495 UT using 105-mm f/4 lens + unfiltered CCD.

The Nova position:

R.A. = 18h07m07s.67, Decl. = -33d46'33".9 (equinox 2000.0)

Independently the same nova has been discovered by All Sky Automated Survey (ASAS) with a telephoto lens 200/2.8, diameter 70 mm + CCD + Johnson V filter.

G. Pojmanski, D. Szczygiel and B. Pilecki of Warsaw University Astronomical Observatory reported ASAS discovery on vsnet-alert 11369. According to ASAS images, the new object was V=7.78 on August 06, 2009.

Asas light curve and images are available here:

Credit: ASAS

Nova Sagittarii 2009 no. 3 has been confirmed spectroscopically as a nova by M. Fujii (Fujii Bisei Observatory, Okayama, Japan). The object shows Balmer series emission lines and Fe II emission lines. The FWHM of Halpha emission is 2300km/sec.

by Ernesto Guido

References:

http://www.astrouw.edu.pl/asas/ (ASAS)

http://ooruri.kusastro.kyoto-u.ac.jp/mailman/listinfo/ (VSNET)

http://www.cbat.eps.harvard.edu/ (CBAT)