Unusual Minor Planet 2012 NJ

MPEC 2012-N19, issued on 2012 July 14, reports the discovery by J75 OAM Observatory, La Sagra with a 0.45-m f/2.8 reflector + CCD of the unusual minor planet 2012 NJ. According to the latest orbital solution available, this object moves along a comet-like orbit with an Inclination of 84.32 deg,  Eccentricity = 0.85, Perihelion distance = 1.29 AU and Period = 24.23 years.

We performed some follow-up measurements of this object, while it was still on the neocp, remotely from the H06 ITelescope network (near Mayhill, NM) on  2012, Jul. 14.3, through a 0.51-m f/6.9 reflector + CCD.  No cometary features are visible in our images, the object has the same aspect of the nearby field stars of similar brightness.

Our confirmation image, stack of 10x10-second exposures (click on it for a bigger version):

Below you can see an animation showing the movement of 2012 NJ (each frame is 10-second exposure). Click on the thumbnail for a bigger version:

On mpml mailing list you can find an interesting discussion about the orbit of this object: 

UPDATE - July 18, 2012

According to Cbet 3178, a 35" tail in p.a. 235 deg has been reported by Gerhard J. Hahn on stacked and single images taken by Stefano Mottola using the 1.23-m telescope on Calar Alto on July 16, 17, and 18 UT. 2012 NJ is now comet P/2012 NJ (LA SAGRA)

Credit: Department of Asteroid and Comet Research, DLR Institute of Planetary Research

by Ernesto Guido, Giovanni Sostero & Nick Howes

"Centaur" minor planet 2010 XZ78

2010 XZ78 is an object found on December 2010 by G96 professional survey and classified as a Centaur. To date, 17 total observations of 2010 XZ78 are present in the MPC database over interval: 2010 11 13.34 – 2011 01 08.25.

Centaurs, defined to have their perihelion outside of Jupiter (5.2 AU) and semimajor axis inside of Neptune (30.0 AU), have unstable orbits and have been extracted from the transneptunian objects (TNOs) population through perturbations by Neptune. So far only a few Centaurs have presented unambiguous evidence of cometary activity (see for example 174P/Echeclus). The first Centaur known to present cometary activity was Chiron.

We performed some follow-up of 2010 XZ78 on 2011 December 06, 2011 to lengthen the observational arc and to search for cometary activity. We found it roughly 2.2 arcminutes west of its nominal position. Stacking of 13 R-filtered exposures, 60-sec each, obtained remotely, from the Haleakala-Faulkes Telescope North on 2011, Dec. 6.4, through a 2.0-m f/10.0  Ritchey-Chretien + CCD, shows that this object has a stellar aspect, with its PSF profile being the same of the nearby field stars of similar brightness  (FWHM of 1.2").

Our image of 2010 XZ78:

by Giovanni Sostero, Nick Howes & Ernesto Guido

Follow-up of 174P/Echeclus bright phase

Following the recent outburst of centaur 174P/Echeclus, we performed some follow-up of this intriguing object. Stacking of 8 unfiltered exposures 300 sec each, obtained remotely, from the Tzec Maun Observatory (near Moorook, Australia) on 2011, June 8.6, through a 0.15-m, f/7.3 refractor + CCD, shows some evolution within the coma of this object: we detected the development of a (possible) faint parabolic envelope about 45-arcsec in diameter, with the central condensation having an offset of nearly 13-arcsec to the west-southwest.

Our image (click on the image for a bigger version):

Unfortunately in our image the S/N of this feature is pretty low, so further follow-up and confirming images will be very welcome.


UPDATE - June 10, 2011

Thanks to our fellow british observer Nick Howes, today we had the opportunity to image 174P/Echeclus nearly simultaneously with both the 2-m Faulkes Telescopes, under excellent seeing conditions, from Haleakala (Hawaii) and Siding Spring (Australia).

Stacking of R-filtered exposures for a total of 930 sec, obtained remotely, from the Haleakala-Faulkes Telescope North on 2011, June 10.4, through a 2.0-m f/10.0 Ritchey-Chretien + CCD under good seeing conditions, confirms the presence of a parabolic envelope, having 47-arcsec in diameter, and a broad tail (or a train of debrises) nearly 20-arcsec long and about 5-arcsecwide, toward PA 70. The nuclear condensation m2 has dropped to R about 19. Confirming observations of the above mentioned features were obtained nearly simultaneously with the Siding Spring-Faulkes Telescope South.

Below you can see our combined image of the two observing sessions, for an equivalent total exposure time of 1530 seconds, R-filtered (click on the image for a bigger version)

by Giovanni Sostero & Ernesto Guido

Outburst of 174P/Echeclus

After reading on the [Comets-ml] forum about a possible outburst of centaur 174P/Echeclus, we performed some follow-up remotely, from the Tzec Maun Observatory (near Moorook, Australia) through a 0.15-m, f/7.3 refractor + CCD. Stacking of 7 unfiltered exposures 300 sec each, show the presence of a sharp central condensation having R magnitude about 18. We noticed also the presence of a jet-like feature nearly 6-arcsec long, emanating from the central condensation toward PA 60. A faint, spiral-like coma, having a total magnitude of about 16 and a diameter of 40-arcsec, surrounds the central condensation, resembling much comet 29P during the early phase of one of its recurrent outbursts.

Our June 01, 2011 image (click for a bigger version):

Centaurs, defined to have their perihelion outside of Jupiter (5.2 AU) and semimajor axis inside of Neptune (30.0 AU), have unstable orbits and have been extracted from the transneptunian objects (TNOs) population through perturbations by Neptune. So far only a few Centaurs have presented unambiguous evidence of cometary activity. The first Centaur known to present cometary activity was Chiron.

Echeclus was discovered by the Spacewatch program on March 3, 2000 (Marsden 2000) and initially labelled (60558) 2000 EC98. The presence of coma around (60558) 2000 EC98 was first detected by Choi and Weissman (2006) on 2005 December 30.50 UT with the Palomar 5m telescope. Soon after, the object was given the periodic comet designation 174P/Echeclus.


Below you can see some of our images dated back to 2006 when the coma was first discovered by Choi & Weissman:

March 2006

April 2006

By Giovanni Sostero & Ernesto Guido

Unusual asteroid 2009 QY6

M.P.E.C. 2009-Q32 , issued on 2009 Aug. 20, announces the discovery of an intriguing object: 2009 QY6. It was picked-up on Aug. 17 with the 1.0-m f/2.15 reflector + CCD of the Lincoln Laboratory ETS team (NM), while it was moving at about 1.2"/min in the morning sky, through the constellation of Aries.

This object has an extremely peculiar orbit (a= 7.35 AU, e= 0.72, i= 137 deg, P= 20.0 years, as for 2009, Aug. 21 MPC website), very similar to that of a comet.

We performed some follow-up of 2009 QY6 while it was still listed in the NEO-CP website (labelled as "BP85104") from the Castelmartini Obs (MPC#160) on 2009, Aug. 19.0, and from the RAS Observatory (MPC#H06) on Aug. 19.4 and 20.4.

In all our stacks, we were consistently unable to identify any cometary feature on this object. Down to the limit of our seeing condition, we always obtained a FWHM profile of 2009 QY6 that was virtually undistinguishible compared to that of nearby field stars having similar brightness.

Stacks from RAS-Mayhill:

According to its preliminary orbit, this curious object might well be a "Damocloid", a few kilometers in diameter. It will reach its perihelion on 2009, OCt. 1, at about 2 AU from the Sun, and it's well worth to keep 2009 QY6 under close scrutiny, in order to check any arise of residual degassing.

Ernesto Guido, Giovanni Sostero, Enrico Prosperi and Paul Camilleri