New Outburst of 174P/Echeclus

On December 08, 2017 B. Skiff reported on mpml mailing list, that the centaur 174P/Echeclus  (also known as 60558 Echeclus) "seems to be at least 4 mag brighter than expected, and indeed as it appeared at the start of last night's images.  The Dec 7 series shows the outburst in progress on images taken near 2:00 and 2:48 UT; it is much brighter now (Dec 8 about 3:30 UT)". Last observations before this outburst had this object at around magnitude 18.

Prompted by this alert, I perfomed some follow-up of 174P/Echeclus and I can confirm that this object is experiencing a bright phase. Unfiltered exposures, 30-seconds each, obtained  remotely from Q62 (iTelescope network) on 2017, December 08.57 (through a 0.50-m f/6.8 astrograph + CCD + f/4.5 focal reducer) reveal 174P as a bright featureless star-like object of magnitude ~14.1 N (click on the image below for a bigger version).

This very interesting object was discovered by Spacewatch in 2000 and initially classified as a minor planet with provisional designation 2000 EC98 (its final minor planet designation is 60558 Echeclus). The presence of coma around it 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. During the years, it experienced many outbursts. You can find info and images on all these past bright phases on this blog.

by Ernesto Guido

Comets & Asteroids - Summary for August & September 2016

During the months of August & September 2016, 10 new comets were discovered, cometary activity was detected for 4 previously discovered object (earlier designated as an asteroid) and there were 3 comet recoveries. "Current comet magnitudes" & "Daily updated asteroid flybys" pages are available at the top of this blog (or just click on the underline text here). 

The dates below refer to the date of issuance of CBET (Central Bureau Electronic Telegram)  which reported the official news & designations.

- Comet Discoveries

Aug 14  Discovery of P/2016 P1 (PANSTARRS)

Aug 14  Discovery of P/2016 P2 (PANSTARRS)

Aug 29  Discovery of P/2016 N6 (PANSTARRS)

Aug 31  Discovery of C/2016 Q2 (PANSTARRS)

Sep 02   Discovery of C/2016 Q4 (KOWALSKI)

Sep 09   Discovery of C/2016 P4 (PANSTARRS)

Sep 09   Discovery of C/2016 R2 (PANSTARRS)

Sep 16   Discovery of C/2016 R3 (BORISOV)

Sep 29   Discovery of C/2016 S1 (PANSTARRS)

Sep 29   Discovery of P/2016 R4 (GIBBS)

- Cometary activity detected

Aug 10  Cometary activity detected in 2014 HU_195 = C/2014 HU_195

Aug 15  Cometary activity detected in 2015 TP_200  = P/2015 TP_200 (LINEAR)

Aug 31  Cometary activity detected in 2008 SH164   = P/2016 Q3 (LINEAR)

Sep 27   Cometary activity detected in P/2009 Q9       = P/2016 SV (PANSTARRS)

- Comet Recoveries

Aug 15  Recovery of P/2003 SQ_215 (NEAT-LONEOS) as P/2016 P3

Aug 31  Recovery of P/2005 S3 (READ) as P/2016 Q1

Sep 03   Recovery of P/2007 T6 (CATALINA) as P/2016 R1

- Other news

Aug 02 July Gamma Draconid meteor shower showed a little outburst between July 27d 23h56m and July 28d 00h23m UT as showed by IMO and CAMS meteor video camera networks and by Canadian Meteor Orbit Radar data. The observed rate translates to a peak zenith hourly rate for a visual observer (assuming a differential mass distribution index of 1.9) of about 50 meteors per hour for the period 0h-1h UT on July 28.

Credit: IMO

Aug 04 A bright sungrazer heading towards the Sun imaged by the ESA/NASA Solar & Heliospheric Observatory SOHO 03 & 04 August 2016.

Credit: SOHO

Sep 01 Comet 174P/ECHECLUS = (60558) ECHECLUS was found in outburst by P. Camilleri, brightening from magnitude r' = 17.8 to 15.2 between Aug 27.745 and 28.686 UT in a photometric aperture of radius 5".2. 

Sep 05 The search for @Philae2014 is OVER! Less than a month before the end of the mission, Rosetta’s high-resolution camera has revealed the Philae lander wedged into a dark crack on Comet 67P/Churyumov–Gerasimenko. The images were taken on 2 September by the OSIRIS narrow-angle camera as the orbiter came within 2.7 km of the surface and clearly show the main body of the lander, along with two of its three legs.

Credit: ESA/Rosetta

Sep 07 Close approach of asteroid 2016 RB1. Asteroid 2016 RB1 (estimated size of 7.3 m - 16 m) had a close approach with Earth at about 0.1 LD (Lunar Distances = ~384,000 kilometers) on 2016, September 7 at 17:20UT reaching a peak magnitude of about +12.3.

Sep 24 Time-resolved observations of the split comet 332P/Ikeya-Murakami were taken using the Hubble Space Telescope.

Credit: D. Jewitt et al.

Sep 30 ESA’s historic Rosetta mission has concluded as planned, with the controlled impact onto the comet it had been investigating for more than two years. Confirmation of the end of the mission arrived at ESA’s control centre in Darmstadt, Germany at 11:19 GMT (13:19 CEST) with the loss of Rosetta’s signal upon impact.

During the the spacecraft’s controlled descent, OSIRIS narrow-angle camera aboard Rosetta imaged comet 67P/Churyumov-Gerasimenko from an altitude of about 16 kilometers above the surface. Credit: ESA/Rosetta

A last image of comet 67P taken by Rosetta shortly before impact at an altitude of 20m above surface. The scale is 2 mm/pixel and the image measures about 96 cm across. Credit: ESA/Rosetta

by Ernesto Guido

Further follow-up of 174P/Echeclus

Today we have been able to image again comet 174P/Echeclus with the 2-m Faulkes Telescope South to follow the recent bright phase of this interesting centaur.

Stacking of eight R-filtered exposures, 60-sec each, obtained remotely, from the Faulkes Telescope South on 2011, June 24.5, through a 2.0-m f/10.0 Ritchey-Chretien + CCD, shows some evolution in the morphology of this comet: the parabolic coma previously reported, albeit present, is now much fainter, and shows its ADU counts very close to the sky background limit. No other details, except a nuclear condensation having an m2 close t R about 18.9, are currently visible in our images.

Click on the image for a bigger version

For more info about this object please see our previous posts:

http://remanzacco.blogspot.com/2011/06/outburst-of-174pecheclus.html

http://remanzacco.blogspot.com/2011/06/follow-up-of-174pecheclus-bright-phase.html

by Nick Howes, Giovanni Sostero and 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