NEO asteroid (4179) Toutatis was discovered by Christian Pollas with the 0.9-m Schmidt at Caussols (France) on 1989, Jan. 4 (IAUC 4701). It is funny to note its naming citation:
“Named after the Gaulish god, protector of the tribe. This totemic deity is well known because of the cartoon series “Les aventures d’Asterix” by Uderzo and Goscinny. This tells the stories of two almost fearless heroes living in the last village under siege in Roman-occupied Gaul in 50 B.C., and whose only fear is that the sky may fall onto their heads one day. Since this object is the Apollo object with the smallest inclination known, it is a good candidate to fall on our heads one of these days… But as the chief of the village always says: “C’est pas demain la veille…” (tomorrow it’s not the day…)
Toutatis is an irregular and very elongated object, with a very slow rotation period of 5.4 days (about the long axis). It approaches Earth at four-year interval, so it has been extensively studied with radar in every perigee.
This last passage, on 2012, December 12, was very favourable with a minimum distance of 0.0463 AU (18 LD): the next time it will approach closer will be in November 2069!
NASA radar team are conducting an extensive campaign using the Goldstone 70-m antenna, from Dec. 4 to 22.
Here you can find images and information about their valuable observations:
Radar imaging is an amazing source of information about asteroids: measurements of the distribution of echo power in time delay (range) and Doppler frequency (radial velocity) create a two-dimensional images that can provide spatial resolution as fine as 4m/pixel (at Goldstone). With good coverage in time these images can be used to define the rotation period, shape and to constrain the object’s internal density distribution.
Here is my image taken just before the closest approach:
On the same date, here is the Goldstone image:
Toutatis was also imaged by Chang’E 2 Chinese spacecraft on Dec. 13, and the image below was obtained from an minimum altitude of 93km. The lower-left image has a resolution of 10m:
2012 XE54 was discovered by R.A. Kowalski with the 0.68-m Schmidt telescope from Catalina Sky Survey (AZ, USA) when it was approaching Earth quite fast.
I observed it the following night just after its exit from the NEO Confirmation Page, with a 0.38-m f/6.8 reflector, when it was 0.011 AU from the Eart, moving at 11.3″/min at mag. 16.4 R.
On December, 10th Pasquale Tricarico (Ph.D., Planetary Science Institute) sent an e-mail on MPML advising the astronomical community that this asteroid “was on its way to cross Earth’s penumbra cone just hours before the flyby, between 01:22 and 02:00 UTC of December 11, 2012”. This was also present in MPES service from MPC and NASA Horizon website.
I had clear night on that date so I decided to try to catch its eclipse. Unfortunately I wasn’t able to catch its “disappearing” in one single long image, but you can see how the streaks of 2012 XE54 became progressively dimmer and dimmer in time.
In these 120-sec images the asteroid was at a mean distance of 470.000 km from us moving at about 170″/min in PA 139.6°:
Also Elia Cozzi from New Millennium Observatory, Mozzate, Italy (A24) imaged this object. Here you can see a couple of images, taken with his 0.36-m f/11 and 60-sec exp, the first one at 01.30 UT and the other one at 01.48 UT, when it was out of the Earth penumbra:
Peter Birtwhistle obtained a preliminary light curve from his images taken between 01.19 UT and 01.50 UT, in which one can clearly note the +4mag drop in luminosity when it entered deep in the Earth penumbra:
C/2012 V2 (LINEAR) was discovered by the LINEAR survey using a 1.0-m f/2.15 reflector from Socorro, NM.
Their moving object detection proedure is not visually inspected by members of the LINEAR team, so cometary appearance at first was not detected. On the basis of the high NEO score it was posted on the NEO Confirmation Page under the temporary designation CE10854, and subsequently it was confirmmed as comet by several other CCD astrometrists.
An alert by Rolando Ligustri from the T3 project brought this target under my attention, and I was able to image it under good sky and seeing conditions on Nov. 07.9, with a 0.38-m f/6.8 reflector + CCD. Its cometary feature was obvious, with a coma 12″ wide elongated in PA around 90°.
Results were published in CBET 3290 (subscription required) and astrometry, together with preliminary parabolic orbital elements and Oct. 30 prediscovery data from MASTER-II Observatory, Blagoveshchensk, Russia) in MPEC 2012-V58.
Ligustri image from CAST Observatory, Talmassons – code 235 (Thanks Rolando!):
C/2012 V1 (PANSTARRS) was discovered by the PANSTARRS survey using a 1.8-m f/4.4 reflector from Haleakala, HI.
Larry Denneau, Richard Wainscoat and Henry Hsieh noted a diffuse, non-stellar appearance on four 45 seconds w-band images, and subsequently it was posted on the NEO Confirmation Page under the temporary designation P104XVd, with also a 100% NEO score.
At first I was able to confirm its cometary appearance with the 2.0-m Faulkes Telescope North, from the same site, under very good seeing conditions (stars FWHM 0.9″-1.0″). In the image below (stack of 9×45 seconds with Bessel R filter) its nature is clear, with a diffuse 4″ coma, and a FWHM 70% larger than stars nearby.
The weather was good also at Schiaparelli Observatory on the same day, so I was able to image it with a 0.38-m f/6.8 reflector. Visually (i.e. on the screen) its aspect was stellar, but the “FWHM method” clearly revealed its nature: profile 30% larger than stars nearby, and a coma 8″ wide.
Also ARI Observatory (H21) detected it on Nov. 05.26, and in the image below, taken with the very good 0.81-m f/4 astrograph stacking 30×60 seconds images, the FWHM method revealed a profile 30-35% larger than stars, and a coma 11″x7″.
This is again a demonstration of how good is the FWHM method (used largely in our T3 project) in discerning comets among asteroids.
Results were published in CBET 3289 (subscription required) and astrometry, together with preliminary parabolic orbital elements, in MPEC 2012-V40.
204 image (and FWHM boxes):
F65 image (and FWHM boxes):
H21 image (and FWHM boxes):
C/2012 T5 (Bressi) was discovered by Terry Bressi, Spacewatch survey, on images taken with the 0.9-m f/3 reflector telescope from Kitt Peak, on Oct. 14.4. She noted the object to be diffuse with an apparent faint tail about 9″ long in PA 260°, and she obtained confirmation images with the 1.8-m f/2.7 reflector (diffuse with a broad tail extending about 10″ in PA about 270 deg).
It was posted on the NEO Confirmation Page under the temporary designation SW40uN, and several other observers noted its cometary appearance, including me at 204-Schiaparelli on Oct. 17.0.
Results were published in CBET 3261 (subscription required) and astrometry, together with parabolic orbital elements, in MPEC 2012-U38.
Some images are visible below.
Image from 204-Schiaparelli:
Image from J04-ESA Optical Ground Station-Tenerife (Image credit: ESA/Knöfel):
Image from F65-Faulkes Telescope North:
Image from H21-ARI:
Image from H06-INet telescopes:
Image from 113-Volkssternwarte Drebach:
P/2012 T7 (Vorobjov) was discovered on 2012, Oct. 15.3 by Tomas Vorobjov from Bratislava, Slovak Republic, using remotely a 0.81-m f/7 Ritchey-Chretien reflector located at the Mt. Lemmon SkyCenter via the Sierra Stars Observatory Network, during a minor-planet search survey undertaken as part of the International Astronomical Search Collaboration (IASC) school campaigns, which I’m proud to be part of.
Three 120 seconds images that he took with Alexander Kostin (Houston, TX, U.S.A.) revealed its cometary appearance, with a tail in PA 270°.
A confirmation set of images were taken by R. Holmes the following night with a 0.61-m f/4 astrograph from Westfield-H21, showing a 6″ coma and a tail 25″ long in PA 260°.
Due to its cometary appearance, it was posted on the NEO Confirmation Page under the temporary designation TOV7DD.
I was able to image it under good seeing conditions but with passing high, thin clouds on Oct. 17. Several other observers then noted its features, including many from IASC and T3 project, and results were published in CBET 3260 (subscription required) and astrometry, together with elliptical orbital elements, in MPEC 2012-U40.
Some images are visible below.
Well done Tomas, let’s hope this is only the first of a long series!!!
Original T.Vorobjov discovery animation from G84:
Confirmation image by ARI-H21:
Image from E10-Faulkes Telescope South:
Image from 204-Schiaparelli:
Image from G96-Mt.Lemmon Survey (thanks to Andrea Boattini):
P/2012 T1 (PANSTARRS) was discovered by the PAN-STARRS survey on 2012, Oct. 06.53 with a 1.8-m reflector + CCD located at Haleakala, HI, USA.
Richard Wainscoat, Henry Hsieh and Larry Denneau described the object to have a PSF larger than stars nearby (1.5″ vs 1.07″). The object was posted on the NEO Confirmation Page under the temprary designation P104kFN.
Apart from their internal confirmation team from Hawaii (Dave Tholen, Marco Micheli and Garrett T. Elliott using the UoH 2.24-m reflector), observatories from the “T3 project” were the only ones to confirm it as a comet.
The first who reported to us cometary activity was Hidetaka Sato, using a 0.43-m remotely from New Mexico on Oct. 10.3, noted that “P104kFN is a potential comet with a round coma of 10″ in diameter. A tail was 12″ toward PA 250 degree.”
After his observation I managed to observe it under a clear sky the following night (the first after three weeks of bad weather in northern Italy!), confirming its clear cometary appearance: in a stack of 56 minutes of total exposure time in good conditions, it has a diffuse aspect, with a coma 10″ wide elongated in PA 253° for at least 15″.
Also H21-ARI confirmed it with a 0.61-m f/4 astrograph from Westfield, IL, USA, on Oct. 11.29: round 12″ coma and a tail 15″ long toward PA 240 degrees.
Also Lulin Observatory from Taiwan confirmed it with the LOT 1.0-m f/8 telescope, but for some reasons they were not included in the circular.
Results were published in CBET 3252 (subscription required) and astrometry, together with elliptical orbital elements, in MPEC 2012-T55. Gareth Williams found prediscovery observations from PAN-STARRS back to 2011, Jul. 28, so the orbit is already pretty solid.
With a semimajor axis of 3.05 AU, low eccentricity and inclination and a Tj parameter of 3.18, P/2012 T1 belongs to the Main-Belt Comets group.
In all the images, visible below, it’s clear the faint and diffuse tail.
H06 (H. Sato) image: