Rosetta flyby of asteroid (21) Lutetia

On July 10, 2010 ESA's Rosetta spacecraft imaged asteroid Lutetia within an estimated distance of 3170 kilometers. Lutetia (the largest asteroid yet visited by a spacecraft) was discovered in 1852 from the Paris balcony of French painter turned astronomer Hermann Goldschmidt. To honour his home city, he called it 'Lutetia', after the Roman name for Paris.

In 2008 Rosetta encountered the asteroid (2867) Steins at a distance of 802.6 km.

All images: CREDIT: (C) ESA 2010 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA

Pre-flyby image! View of Lutetia at a distance of 80,000 km.

Lutetia imaged just before its closest approach with Rosetta

At a distance of 36 000 km, Rosetta took this image of Lutetia with the planet Saturn in the background.

Lutetia close approach by Rosetta - Animation (click for a bigger version)

Next Rosetta rendezvous, scheduled for 2014, is with comet 67P/Churyumov-Gerasimenko. This comet rendezvous is the ultimate goal of Rosetta in the attempt to try to solve some of the enigmas of our Solar System.

by Ernesto Guido

Impact Flash on Jupiter

Amateur astronomers Anthony Wesley (Australia) and Christopher Go (Philippines) have independently observed an impact flash on Jupiter. According to their images and videos, the impact flash happened at 20:31 UTC of June 3, 2010 and lasted only few seconds in Jupiter's faded south equatorial belt. The alert was first launched by Wesley and soon after confirmed by Go who happened to imaging the planet at the same time.

Credit: A. Wesley

Credit: Christopher Go

Wesley suggests that the impact "doesn't seem to have left any mark, so it probably burned up in the upper atmosphere before it reached the cloud deck. There were no visible remains at the impact point for the next half hour or so, until sunrise put an end to the imaging."

According to S&T website: "The flare occurred at longitude 248.8° in Jupiter's System I, 342.7° in System II, and 159.4° in System III. The latitude is 16° south. This region should be visible from about 4:00 to 6:30 June 4th UT, favoring observers in Europe and Africa when Jupiter is up before dawn. The impact site will return to good view about every 9 hours 56 minutes thereafter."

Major telescopes will be pointed on the area as soon as possible. So it's likely that we'll have more info available in the next few hours.

Link to Wesley webpage about this event (where you can download his 45MB video):

Link to download the video of this event by C. Go

Anthony Wesley was also the discoverer of the impact scar on Jupiter on July 2009.

For more info about the 2009 impact:

http://remanzacco.blogspot.com/2009/07/nasa-images-confirm-jupiter-impact.html

http://remanzacco.blogspot.com/2009/07/new-impact-on-jupiter.html

http://bit.ly/d6KuEM (Hubble Images of the scar)

http://bit.ly/cGOI1P (Published results on the Jupiter impact appeared in ApJ Letters)

UPDATE JUNE 16, 2010

Unlike previous impacts, Hubble imaging of the June 3rd impact site revealed no debris scar. The impact flash came from a giant meteor burning up high above Jupiter's cloud tops. The space visitor did not plunge deep enough into the atmosphere to explode and leave behind any telltale cloud of debris, as seen in previous Jupiter collisions.

Image Credit: NASA, ESA, M.H. Wong (University of California, Berkeley), H.B. Hammel (Space Science Institute, Boulder, Colo.), A.A. Simon-Miller (Goddard Space Flight Center), and the Jupiter Impact Science Team.

"We suspected for this 2010 impact there might be no big explosion driving a giant plume, and hence no resulting debris field to be imaged. There was just the meteor, and Hubble confirmed this," adds Hammel, a veteran Jupiter observer of the 1994 string of impacts.

by E. Guido & G. Sostero

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:
http://remanzacco.blogspot.com/2009/09/new-comet-discovery-c2009-r1-mcnaught.html

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

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:

http://bit.ly/9hZyoH

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

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

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