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.

V1311 SCORPII = NOVA SCORPII 2010 No. 2

by Ernesto Guido and 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

New Comet: P/2010 H2

CBET circular No. 2249, issued on 2010, April 17, announces the discovery by J. Vales of an unusually bright (magnitude 12.6) asteroidal object on Apr. 16, 2010, observing with the 0.60-m f/3.3 Deltagraph at Crni Vrh (mpc code 106), Slovenia. R. A. Kowalski of Catalina Sky Survey (CSS), reports that the object is not visible in images down to magnitude V=20 obtained by the CSS Survey as recently as April 15.4 UT.

After posting on the Minor Planet Center's NEOCP webpage, W. Ryan (H01) and E. Guido & G. Sostero (H06) have commented that the new object has an FWHM consistently wider (about 10%) than nearby field stars of similar brightness, confirming the cometary nature of this object designated P/2010 H2.

We have been able to confirm this object remotely, through the GRAS network, using a scope located in Mayhill (NM): Analysis of the stacking of 6 ulfiltered exposures, 120-seconds each,obtained remotely on 2010 Apr. 16.42 show that this object has an FWHM consistently wider than the nearby field stars of similar brightness. An additional stacking,of 6 unfiltered exposures, 30-sec each, obtained through the same instrumentation on 2010 Apr. 16.43, confirm this evidence. In our opinion, its appearance strictly resembles that of comet 17P/Holmes in the early phases of its October 2007 outburst phase.

Our confirming image:

The still-very-preliminary elliptical orbit shows perihelion on May 21, 2010, at about 3.07 AU.

Follow-up observations are strongly encouraged. It is expected that an expanding coma will develop over the next days and weeks.

by Ernesto Guido & Giovanni Sostero

Fireball over Wisconsin - Missouri , April 14

A bright fireball has been seen over Wisconsin aroud 10:00 p.m. local time of April 14, 2010. The fireball has been seen from Wisconsin to Missouri. National Weather Service offices in La Crosse, Wisconsin, Davenport and Des Moines, Iowa, and St. Louis and Kansas City in Missouri all received numerous reports.

Many surveillance cameras should have recorded the night-landscape illuminated by the fireball.

The fireball was caught on a webcam from University of Wisconsin-Madison Department of Atmospheric and Oceanic Sciences:

Please click on animation to see a bigger version

(Credit: UW-Madison AOS/SSEC)

The fireball was also caught by a Howard County Iowa Sheriff's Deputy.  Also the Doppler Radar from the National Weather Service in the Quad Cities appeared to capture a portion of the smoke trail from the fireball at 1002 PM local time (CDT), as seen in the image below. It appears as a thin line extending across portions of Grant and Iowa Counties in Wisconsin. Click on the image to see a bigger version.

By Ernesto Guido

New Comet: C/2010 G2 (HILL)

IAU circular No. 9134, issued on 2010, April 11, announces the discovery by R. E. Hill of a new comet on Apr. 10, 2010, in the course of the Catalina Sky Survey. After posting on the Minor Planet Center's NEOCP webpage, many observers have noted the cometary appearance of this 19.5 magnitude object, designated C/2010 G2 (HILL).

We have been able to confirm this object remotely, through the GRAS network, using a scope located in Mayhill (NM): on 2010, April 11.3, co-adding of 18 unfiltered exposures, 120-seconds each obtained by means of a 0.25-m, f/3.4 reflector + CCD, show a diffuse coma 10-arcsec in diameter.

Our confirming image:

The first and preliminary orbit for comet C/2010 G2 (Hill) indicates perihelion Jun. 19, 2011, at about 1.3 AU. The comet might reach 11m or brighter.

According to COCD, this is the 88th comet for the Catalina Sky Survey and the 22nd for Hill.

by Ernesto Guido & Giovanni Sostero

New Bright Sungrazing Comet

Another bright sungrazing comet appeared on the coronagraph image of April 09, 2010 from the Solar and Heliospheric Observatory (SOHO).

This is 4th bright sungrazing comet of 2010.

You can read more details about these other comets on our old posts:

http://remanzacco.blogspot.com/2010/01/bright-sungrazing-comet.html
http://remanzacco.blogspot.com/2010/01/new-sungrazing-comet.html
http://remanzacco.blogspot.com/2010/03/new-sungrazing-comet.html

C2 Movie (click to see a bigger version)

(Credit: SOHO)

Like its predecessors, this comet probably will not survive this close encounter with the Sun.

by Ernesto Guido

New Comet: C/2010 G1 (BOATTINI)

IAU circular No. 9133, issued on 2010, April 06, announces the discovery by A. Boattini of a new comet on Apr. 05, 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 14 magnitude object, designated C/2010 G1 (BOATTINI).

The object described by the discoverer as diffuse with a strong, condensed coma about 40" in size, and a fainter coma out to a diameter about 2' that fades into the background; the coma is slightly elongated in p.a. 50-55 deg.

Discovery image (4x20seconds exposures):

(Credit: A. Boattini - CSS Survey)

The first and preliminary parabolic orbit for comet C/2010 G1 (BOATTINI) indicates perihelion on Apr. 06, 2010, at about 1.20 AU.

This is the 87th comet for the Catalina Sky Survey and the 13th for Andrea Boattini.

by Ernesto Guido