Sunday, May 30, 2010

Comet C/2009 R1 (McNaught) - Animation & Images

Comet C/2009 R1 has been discovered in September 2009 by Robert H. McNaught in the course of Australia’s Siding Spring Survey.

For more information about the discovery of this comet, please see our previous post:

The comet is now around magnitude 7.5 and it will be a nice binocular object. Throughout this apparition it will be low in the east or northeast when dawn begins to brighten.

In our images, taken on May 26, is clearly visible a nice disconnection event (DE) in the plasma tail of the comet C/2009 R1. Occasionally due to comet-solar wind interaction, the entire plasma tail or part of it separates from the comet and drift away (antisunward), followed by simultaneous renewal of the plasma tail. This phenomena is called a disconnection event.

Here & here you can see bigger versions of this image:

Wide-field animation of comet C/2009 R1 (May 26, 2010), showing the DE event:

Wide-Field Image (May 26, 2010):

by Ernesto Guido & Giovanni Sostero

Wednesday, May 26, 2010

Photos of MACE 2010

Photos from the MACE 2010 (Meeting on Asteroids and Comets in Europe) held in and around Višnjan/Tićan, Croatia, on the long weekend of May 21-23, 2010:

Thursday, May 13, 2010

New Comet: C/2010 J3 (MCMILLAN)

IAU circular No. 9146, issued on 2010, May 13, announces the discovery by R. S. McMillan of a new comet on May 12, 2010, with the Spacewatch 0.9-m f/3 reflector at Kitt Peak. After posting on the Minor Planet Center's NEOCP webpage, many observers have commented on the cometary appearance of this 17.5 magnitude object, designated C/2010 J3 (MCMILLAN).

We have been able to confirm this object remotely, through a 0.18-m refractor, f/7.3 + CCD at Tzec Maun Observatory near Mayhill, NM, U.S.A.: on 2010, May 12.4, co-adding of 10 unfiltered exposures, 180-seconds each, show a compact coma about 12" in diameter, with a sharp central condensation; broad tail nearly 20" long toward PA 265 deg.

Our confirming image:

The first and preliminary parabolic orbit for comet C/2010 J3 (MCMILLAN) indicates perihelion Sept. 28, 2010, at about 2.2 AU.

by G. Sostero, E. Guido, L. Donato

Sunday, May 9, 2010

Cataclysmic Variable in Pegasus

CBET circulars No. 2273 & 2275, issued on May 08, 2010, announces the discovery by Dae-Am Yi (Korea) of an apparent new object (mag about 10.8) on two images taken on May 6.77 with a Canon 5D digital camera (+ 93-mm camera lens). CBET 2275 reports independent discovery of the outburst of this variable by Shizuo Kaneko.

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 May 09.4, 2010 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude about 8.5 (UCAC2 Catalogue reference stars) at coordinates:

R.A. = 21 38 06.57, Decl.= +26 19 58.2

(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 - 1991). The archive plates show a close pair of objects at the location of the outbursting variable (GSC 2197:886):

Based upon an examination of the POSS-I and POSS-II plates by Arne Henden (AAVSO), it is possible that the double is composed of two unassociated stars, one with a high proper motion.

Spectrum obtained on May 8.47 UT with the 1.82-m Plaskett Telescope of the National Research Council of Canada, shows strong H-alpha and H-beta in emission (HWFM 800 km/s). Another spectrum obtained using the 1.3-m ARAKI telescope on May 8.66 UT shows a blue continuum and a weak H-alpha emission line, suggesting that the object would be classified as a dwarf nova. (cf. CBET 2275).

According to Taichi Kato (VSNET), given the current brightness (and no known past outburst record), the object may be a large-amplitude WZ Sge-type dwarf nova undergoing a rare outburst!

by Ernesto Guido and Giovanni Sostero

Friday, May 7, 2010

New Comet: C/2010 J1 (BOATTINI)

IAU circular No. 9143, issued on 2010, May 07, announces the discovery by A. Boattini of a new comet on May 06, 2010, with the 0.68-m Schmidt telescope in the course of the Catalina Sky Survey. After posting on the Minor Planet Center's NEOCP webpage, many observers have commented on the cometary appearance of this 16 magnitude object, designated C/2010 J1 (BOATTINI).

We have been able to confirm this object remotely, through the GRAS network, using a scope located in Mayhill (NM): on 2010, May 6.4, co-adding of 10 unfiltered exposures, 60-seconds each obtained by means of a 0.25-m, f/3.4 reflector + CCD, show a diffuse coma nearly 15-arcsec in diameter, plus a broad, fan-shaped tail about 1-arcmin long toward south-east.

Our confirming image:

Our follow-up image taken on May 07, 2010:

The first and preliminary parabolic orbit for comet C/2010 J1 (BOATTINI) indicates perihelion Jan. 31, 2010, at about 1.6 AU.

This is the 90th comet for the Catalina Sky Survey and the 14nd for Boattini.

by Ernesto Guido & Giovanni Sostero