Monday, October 13, 2014

New fragmentation event in C/2011 J2 (LINEAR)

Starting from 2014, Sept 26.9 we are constantly monitoring comet C/2011 J2 (LINEAR) and his fragment B through a 2.0-m f/10.0 Ritchey-Chretien + CCD (La Palma-Liverpool Telescope). The video below shows an animation we made using our recent obs of this comet. Time span is 9 days (from 1 Oct. to 9 Oct). The projected velocity of the fragment is of about 0.3 arcsec/day.



While performing follow-up of component B of comet C/2011 J2 on 2014, Oct 09.9  we detected a possible new diffuse fragment located in the very near proximity of main component A. Nothing was visible on our images taken on Oct. 07.9. Below you can see our Oct. 09.9 image of the new fragment (division by azimutal median filter applied). Click here or on the image below for a bigger version.


We imaged again C/2011 J2 on Oct. 11.9 with the same setup and we confirmed the presence of a new fragment located 1.5" in PA 59 from the main component A. Below you can see our Oct. 11.9 image of the new fragment (stack of 10x20sec raw images, no filters applied). Click here or on the image below for a bigger version. 


While the new fragment is already visible in the raw images, it is even more clearly highlighted by using an appropriate filter. So below you can see the same image as above with a division by azimutal median filter applied. Click here & here or on the images below for a bigger version.


This filter creates an artificial coma, based on the photometry of the original image, and divide the original image itself in order to highlight the internal zones of different brightness that  are very close to the inner core and that would normally be hidden from the diffuse glow of the comet. Precise astrometry/photometry is difficult to obtain due to the extreme proximity and diffuse appearance of new fragment to main component A. New fragment on 2014, Oct 11.9 is definitely brighter than fragment B.

by Ernesto Guido, Nick Howes & Martino Nicolini

Wednesday, October 1, 2014

Follow-up of splitting event in Comet C/2011 J2

CBET 3979, issued on 2014 September 19, announced that observations of comet C/2011 J2 (LINEAR) (by F. Manzini, V. Oldani, A. Dan and R. Behrend) on Aug. 27.95, 28.85, and 30.91 UT led to the detection of a second, fainter, nuclear condensation (from now on Component B) located 0".8 east and 7".5 north of the main, brighter nuclear condensation (component A).

For more info about comet C/2011 J2 please see our May 2011 post on this blog by clicking here.

Whilst working on a long term morphology study on comet C/2012 K1 with N. Samarasinha and B. Mueller using the 2-meter Liverpool Telescope, we were alerted of the fragmentation event in comet C/2011 J2 and so diverted the telescope to this comet for a few days.

Our follow-up images were taken on 2014, Sept 26.9 through a 2.0-m f/10.0 Ritchey-Chretien + CCD (La Palma-Liverpool Telescope). Stacking of 10 SDSS-R filtered exposures, 20-sec each, shows component B at 14" away in PA 17 from component A. Magnitude of component B is about R = 19.5

Below you can see our follow-up image that clearly shows comet C/2011 J2 (LINEAR) and its seconday B component. Click on it for a bigger version.




For some examples of past comet fragmentation events please check the following links:


UPDATE - October 05, 2014

In the video below we show a first attempt to measure component B drifting movement from the nucleus of comet C/2011 J2 on 2014, through a 2.0-m f/10.0 Ritchey-Chretien + CCD (La Palma-Liverpool Telescope). Blinking the frames of Sept. 26.9 and Oct 02.9, there is evidence of fragment B moving off from the main comet component while profile graphs show that fragment is fading and less condensed. On Sept 26.9 the distance is of 14.4 arcsec. whilst on Oct. 2.9 the distance from the nucleus is of 15.6 arcsec. Click here to see a bigger version of the video.



by Ernesto Guido, Nick Howes & Martino Nicolini

Friday, September 5, 2014

Close Approach of Asteroid 2014 RC

The asteroid 2014 RC was discovered (at ~ magnitude +20.0) on 2014, September 01.2 by Catalina Sky Survey (MPC code 703) with a 0.68-m Schmidt + CCD (and independently detected the next night by the Pan-STARRS survey).

2014 RC has an estimated size of 12 m - 26 m (based on the object's absolute magnitude H=26.8) and it will have a close approach with Earth at about 0.1 LD (Lunar Distances = ~384,000 kilometers) or 0.0003 AU (1 AU = ~150 million kilometers) at 1801 UT on 2014, September 07. This asteroid will reach the peak magnitude about +11.5 on Sep 7 between 17UT and 18UT.

We performed some follow-up measurements of this object on 2014, September 05.3, remotely from the U69 iTelescope network (Auberry California, USA) through a 0.61-m f/6.5 astrograph + CCD). Below you can see our image taken with the asteroid at about magnitude +17.4 and moving at ~ 1.71 "/min. At the moment of its close approach on Sep 7, around 18UT, 2014 RC will move at ~ 3300 "/min. Click on the image below to see a bigger version. North is up, East is to the left.


The graphic below depicts the passage of asteroid 2014 RC past Earth on September 7, 2014. At time of closest approach, the space rock will be about one-tenth the distance from Earth to the moon. Times indicated on the graphic are Universal Time.

Image credit: NASA/JPL-Caltech

UPDATE - September 07, 2014

Image of asteroid 2014 RC on Sep 07 at 17:30UT,  about 30 minutes before its close approach. The asteroid was at magnitude +11.2 and moving at 2971 "/min (the asteroid is trailed in the image due to its fast speed). Click on the image below to see a bigger version. North is up, East is to the left.



by Ernesto Guido, Nick Howes & Martino Nicolini

Monday, August 25, 2014

New Comet: C/2014 Q3 (BORISOV)

Cbet nr. 3936, issued on 2014, August 24, announces the discovery of a comet (magnitude ~17) by G. Borisov (Observatory MARGO, Nauchnij) on CCD images obtained with a 0.3-m f/1.5 astrograph telescope on 2014, August 22.02. The new comet has been designated C/2014 Q3 (BORISOV).

We performed follow-up measurements of this object, while it was still on the neocp. Stacking of 10 unfiltered exposures, 60-sec each, obtained remotely on 2014, August 23.4 from H06 (iTelescope network - Mayhill) through a 0.50-m f/6.8 astrograph + CCD + f/4.5 focal reducer, shows that this object is a comet: coma about 7" in diameter elongated toward PA 215 (the comet was about +21 degree above the horizon at the moment of the imaging session).

Our confirmation image (click on it for a bigger version)


M.P.E.C. 2014-Q38 assigns the following parabolic orbital elements to comet C/2014 Q3: T 2014 Nov. 19.24; e= 1.0; Peri. = 48.40; q = 1.63;  Incl.= 90.49

This is the third comet discovered by Gennady Borisov (previous were C/2013 N4 & C/2013 V2).

by Ernesto Guido, Nick Howes & Martino Nicolini

Wednesday, August 6, 2014

Rosetta has arrived at comet 67P!

After an epic 10-year journey, the European Space Agency’s Rosetta spacecraft arrived today August 06, 2014 at comet 67P/Churyumov–Gerasimenko becoming the first spacecraft to rendezvous with a comet.  Launched in March 2004, Rosetta had to make three gravity-assist flybys of Earth and one of Mars to help it on course to its rendezvous with the comet. This complex course also allowed Rosetta to pass by asteroids ┼áteins and Lutetia, obtaining unprecedented views and scientific data on these two objects. 

Rosetta woke up from deep space hibernation on 20 January 2014, nine million kilometres from comet 67P/Churyumov–Gerasimenko. Following wake-up, the orbiter’s 11 science instruments and 10 lander instruments were reactivated for science observations. Ten orbital correction manoeuvres were carried out between 7 May and 6 August, reducing the spacecraft’s velocity with respect to the comet from 775 m/s to 1 m/s, equivalent to walking pace. All this in preparation for the first landing on a comet expected on November.

Below you can see a high resolution (5.3 meters per pixel) image of comet Churyumov-Gerasimenko taken by OSIRIS/ROSETTA on August 3, 2014 (so 3 days before entering orbit) from a distance of 285 kilometers. Click on the image for a bigger version.


Copyright: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Below here's another image , showing the "other" side of the comet 67P. The two images are separated by about 4 hours (120 degree comet rotation). Click on the image for a bigger version.


Copyright ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Comet 67P/Churyumov-Gerasimenko activity on 2 August 2014. The image below was taken by Rosetta’s OSIRIS wide-angle camera from a distance of 550 km. The exposure time of the image was 330 seconds and the comet nucleus is saturated to bring out the detail of the comet activity. Note there is a ghost image to the right. The image resolution is 55 metres per pixel. Click on the image for a bigger version.

Copyright ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

The animation below comprises 101 images acquired by the Navigation Camera on board ESA's Rosetta spacecraft as it approached comet 67P/C-G in August 2014. The first image was taken on 1 August at 11:07 UTC (12:07 CEST), at a distance of 832 km. The last image was taken 6 August at 06:07 UTC (08:07 CEST) at a distance of 110 km. Click here or on the thumbnail before for a bigger version.

 Navigation Camera on board ESA's Rosetta spacecraft as it approached comet 67P/C-G in August 2014 photo NavCam_animation_6_August_node_full_image_2_zpsd78d86fd.gif


According to the official ESA press release
Comet 67P/Churyumov–Gerasimenko and Rosetta now lie 405 million kilometres from Earth, about half way between the orbits of Jupiter and Mars, rushing towards the inner Solar System at nearly 55 000 kilometres per hour.  Today, Rosetta is just 100 km from the comet’s surface, but it will edge closer still. Over the next six weeks, it will describe two triangular-shaped trajectories in front of the comet, first at a distance of 100 km and then at 50 km. At the same time, more of the suite of instruments will provide a detailed scientific study of the comet, scrutinising the surface for a target site for the Philae lander. Eventually, Rosetta will attempt a close, near-circular orbit at 30 km and, depending on the activity of the comet, perhaps come even closer. As many as five possible landing sites will be identified by late August, before the primary site is identified in mid-September. The final timeline for the sequence of events for deploying Philae – currently expected for 11 November – will be confirmed by the middle of October. After landing, Rosetta will continue to accompany the comet until its closest approach to the Sun in August 2015 and beyond, watching its behaviour from close quarters to give us a unique insight and realtime experience of how a comet works as it hurtles around the Sun


In November 2014, a small lander (named Philae) will leave the spacecraft and will harpoon itself to the surface of the comet 67P.



Below you can find an image of comet 67P taken by our team (Nick Howes, Giovanni Sostero, Alison Tripp and Ernesto Guido) on 25 April 2012, when comet was at roughly 5.683 AU from the Sun (so close to its aphelion) and of magnitude ~22. For more info on that imaging session and also for our image of this comet dated back to 2010 click here & here.


This blog will be updated as soon as new images and news will arrive so stay tuned!


UPDATE - August 06, 2014 @13:00UT

Stunning close up detail focusing on a smooth region on the ‘base’ of the ‘body’ section of comet 67P/Churyumov-Gerasimenko. The image was taken by Rosetta’s OSIRIS narrow-angle camera and downloaded today, 6 August. The image clearly shows a range of features, including boulders, craters and steep cliffs. The image was taken from a distance of 130 km and the image resolution is 2.4 metres per pixel. Click on the image for a bigger version.


Copyright ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

While below there is a close-up detail of comet 67P/Churyumov-Gerasimenko. The image was taken by Rosetta’s OSIRIS narrow-angle camera and downloaded today, 6 August. The image shows the comet’s ‘head’ at the left of the frame, which is casting shadow onto the ‘neck’ and ‘body’ to the right. The image was taken from a distance of 120 km and the image resolution is 2.2 metres per pixel. Click on the image for a bigger version.


Copyright ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

UPDATE - August 06, 2014 @18:00UT

The View From Rosetta - Animation of comet 67P recorded by Rosetta's navigational camera. (Credit: European Space Agency/BBC News). Click here or on the thumbnail below for a bigger version.

Comet 67P - Credit: European Space Agency/BBC News photo rosetta-comet-67p-orbit-525_zpsc9ba2c58.gif

UPDATE - August 08, 2014 @16:00UT

Full-frame NAVCAM image taken on 5 August 2014 from a distance of about 145 km from comet 67P/Churyumov-Gerasimenko. Click on the image for a bigger version.

Credits: ESA/Rosetta/NAVCAM

Full-frame NAVCAM image taken on 7 August 2014 from a distance of about 83 km from comet 67P/Churyumov-Gerasimenko. Click on the image for a bigger version.

Credits: ESA/Rosetta/NAVCAM

An extract from the last post on Rosetta blog:

"Now that comet 67P/Churyumov-Gerasimernko is within our reach, Rosetta’s mass spectrometer COSIMA, managed by the Max Planck Institute for Solar System Research in Germany, is beginning to reach for cometary dust. Literally. On Sunday 10 August 2014, COSIMA will expose its first of 24 targetholders aiming to collect single dust particles. This might take a while. After all, from dust particle modeling, 67P/C-G’s coma is still comparable to a high-quality cleanroom. But, as 67P/C-G travels closer to the Sun along its orbit, the comet’s activity will increase and more dust will be within reach. For now, we are planning to keep the target exposed for one month, but checking on a weekly basis if the model predictions are not too low and if we are lucky."

UPDATE - August 23, 2014

The image below shows Comet 67P/Churyumov-Gerasimenko imaged by Rosetta's OSIRIS narrow angle camera on 7 August from a distance of 104 km. "While the comet’s head (in the top half of the image) is covered with parallel linear features, the neck displays scattered boulders on a smooth underground. In comparison, the comet’s body (lower half of the image) seems to have much more jagged features.". Click on the image for a bigger version.

Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

A 2 day meeting started today at @CNES_France where scientists and engineers (the Landing Site Selection Group (LSSG)) will select 5 possible landing sites for Philae that will be announced on Monday. Final decision will be confirmed by the middle of October. To see how many factors influence the decision for the landing site see this blog post on Rosetta website.

According to Rosetta blog: "The Global Mapping phase runs 10 September to 7 October, and will see Rosetta going down to just 29 km distance, a point when we expect the spacecraft to become actively captured by the comet’s gravity, and its orbit to become circular. The aim is to get down to 19km height, keeping Rosetta on the Sunlit side or orbiting on the terminator line."

Below you can see the most recent image released by Rosetta taken by its navigation camera (NAVCAM) on 22 August 2014 at a distance of about 64 km from comet 67P. Click on the image for a bigger version.

Credits: ESA/Rosetta/NAVCAM


Below a Rosetta-67P related cartoon by Stephen Collins for the The Guardian . Click on the image for a bigger version.

Credits: Stephen Collins


UPDATE - September 30, 2014

Below you can find a summary of latest news about Rosetta mission. (Click on each image for a bigger version.)

- Site J marks the spot where @Philae2014 will land on comet 67P. Full story on Rosetta blog here.


- Amazing comet 67P image taken by @ESA_Rosetta NAVCAM on 19 Sep 2014 from 28.6 km with jets emanating from the neck region 


- New comet #67P four-image mosaic by @ESA_Rosetta NAVCAM taken on 24 Sept 2014 from 28.5 km + + zoom on large boulders (several metres across) lying in the smooth ‘neck’ region



-  The date is set! @Philae2014 will land on comet 67P on 12 November 2014

by Ernesto Guido

Sunday, July 13, 2014

New Comet: C/2014 N3 (NEOWISE)

Cbet nr. 3921, issued on 2014, July 13, announces the discovery of a comet (~ magnitude 17) by the  Near-Earth Object Wide-field Infrared Survey Explorer (or NEOWISE; formerly the WISE satellite) team on images taken with the NEOWISE satellite on 2014, July 04.5. The new comet has been designated C/2014 N3 (NEOWISE).

We performed follow-up measurements of this object, while it was still on the neocp. Stacking of 10 unfiltered exposures, 60-sec each, obtained remotely on 2014, July 09.6 from Q62 (iTelescope network - Siding Spring) through a 0.50-m f/6.8 astrograph + CCD + focal reducer, shows that this object is a comet: coma about 15" in diameter elongated toward PA 200 (the comet was about +21 degree above the horizon at the moment of the imaging session).

Our confirmation image (click on it for a bigger version)


M.P.E.C. 2014-N72 assigns the following parabolic orbital elements to comet C/2014 N3: T 2015 Mar. 15.67; e= 1.0; Peri. = 354.49; q = 3.84;  Incl.= 61.73

UPDATE - July 15, 2014

In the image below you can see comet C/2014 N3 on the infrared discovery frame taken by NEOWISE and (on the right) a follow-up image taken by J. Masiero through the 8 meter GEMINI telescope in Chile. (More info on the caption. Click on the image for a bigger version).

Credit: A. Mainzer

by Ernesto Guido, Nick Howes & Martino Nicolini

Wednesday, July 9, 2014

Close Approach of PHA Asteroid 2014 MF6

The asteroid 2014 MF6 was discovered (at magnitude ~17.0) on 2014, June 23.3 by Catalina Sky Survey (MPC code 703) with a 0.68-m Schmidt + CCD.

According to the preliminay orbit, 2014 MF6 is an Apollo type asteroid. This class of asteroids are defined by having semi-major axes greater than that of the Earth (> 1 AU) but perihelion distances less than the Earth's aphelion distance (q < 1.017 AU). It is also flagged as a "Potentially Hazardous Asteroid". PHA are asteroids larger than approximately 100m that might have threatening close approaches to the Earth (they can come closer to Earth than 0.05 AU).

2014 MF6 has an estimated size of 190 m - 420 m (based on the object's absolute magnitude H=20.7) and it will have a close approach with Earth at about 9.1 LD (Lunar Distances = ~384,000 kilometers) or 0.0233 AU (1 AU = ~150 million kilometers) at 1939 UT on 2014, July 09. This asteroid will reach the peak magnitude ~15.3 on the period from 06 to 09 July 2014.

We performed some follow-up measurements of this object on 2014, July 09.4, remotely from the Q62 iTelescope network (Siding Spring, AU) through a 0.50-m f/6.8 astrograph + CCD + focal reducer). Below you can see our image taken with the asteroid at magnitude ~15.3 and moving at ~ 40.43 "/min.  Click on the image below to see a bigger version. North is up, East is to the left (the asteroid is trailed in the image due to its fast speed).


Below you can see a short animation showing the movement of 2014 MF6 (three consecutive 60-second exposure). Click here or on the thumbnail below to see the animation (East is up, North is to the right):

Close Approach of asteroid 2014 MF6 photo 2014_MF6_09_July_2014_zpsb8d70b94.gif


by Ernesto Guido, Nick Howes & Martino Nicolini