Asteroid 2015 TB145 (PHA) close and bright flyby Oct 31

UPDATE: Oct 31st, 2015. Live coverage of Asteroid 2015 TB145.

Image Credit: P.Lake 10 Sec image from U69 T24 - travelling at 115 arc"/m at PA 35.4 07:00 UT (Available for media use with attribution to this blog)

Compare the two images - Above a 10 sec image, Below a two minute image which was stacked for movement of the asteroid.

UPDATE: Oct 31st, 2015 - From the NASA Press release this morning the amazing radar images have shown a dark dead comet,(and I am not making this up) looks not unlike a skull. The radar run went well getting down to a resolution of 7 meters per pixel. Its interesting those depressed areas are likely impact craters or collapsed areas from which the jets emerged when the comet was active. Recent studies of 67P by Rosetta have shown collapsed areas on Comet 67P where jets seem to originate from. This comet has been long dead, some studies have already been done to check for past meteor showers originating from its orbit - see the post on the SETI Institute Blog. Also from the press realease: "NASA values the work of numerous highly skilled amateur astronomers, whose accurate observational data helps improve asteroid orbits....". I hope to have more images tonight (weather permitting) - stay tuned.

Image credit: NAIC-Arecibo/NSF

UPDATE: Oct 27th, 2015 - Great set of images last night in the pre-dawn sky from New Mexico. The asteroid has brightened to Mag 15.8 and its apparent speed across the sky is starting to increase as it gets closer. [Also I should probably point out the faint halo you may be able to see is due to the strong moonlight reflecting off some dust on the primary mirror - the full moon was only 36 degrees away]

UPDATE: Oct 24th, 2015 - Finally got some images. The asteroid has brightened considerably to Mag 16.8/9 ish. No signs of cometary activity at this point. Its moving at 0.39arc"/m in a 120 sec image (so 0.78arc" in the image)and the pixel plate scale is 0.53 arc"/pixel so you can see a hint of softness on the trailing side. Definitly no cometary activity though - that's as close as I can go to getting it as sharp as you can get it.

Image Credit: P.Lake 2015 TB145 9x120 secs on the 0.7m Burnell, Cannon, Leavitt Telescope (BCL) T27 at Q62, SSO.

UPDATE: Oct 22nd, 2015 - Getting frustrated, the observatory has been closed due to bad weather for 4 nights.

UPDATE: Oct 17th, 2015 - NASA have updated details of the planned radar runs and expect to be able to get images with a resolution of 2 meters per pixel, they expect it to be the best radar run of the year. Also one other interesting aspect is the Tisserand parameter has been calculated at 2.937 which is just lower than the theoretical "boundary" (of 3.0) between Asteroid and Jupiter Family Comets. The other target of a radar run on 29th is 2009 FD, a well studied Apollo Asteroid, has a Tisserand parameter of 5.295. The seeing was a bit poor on the 14th so the image wasn't strong enough. The relative speed (across the camera chip) will slow to only 0.17 arc"/min on the 19th so I'll be able to stack the images really deep and get a good look at it. If the seeing is better tonight we might even get some more detail. I did look a bit fuzzy the other night but as you can see in the video the satellite that trailed through was very fuzzy as well - so I'm not reading to much into that at the moment.

Image/Video Credit: 2015 TB145 from H06, 12 x 180 sec exp stacked 4x3, 0.5m Planewave October 14th - P.Lake

A couple of times a year, the asteroid surveys throw up a surprise, with a large asteroid approaching very close to the Earth, with little advance notice. After last week's blog post about the Blogsphere overeacting to an Asteroid that astronomers knew about for 15 years passing at 65 Lunar Distances (LD), the "surprise" of course had to happen this week.

This will be an interesting two weeks, as Asteroid 2015 TB145 will cruise by Earth just outside 1 Lunar distance (1.3 LD). The asteroid is a target of the Arecibo Observatory (that big antenna that rose out of the lake in the majestic James Bond scene), and to get some really great radar tracking and detailed images, the ephemeris and position of the asteroid needs very high precision.

To give you an idea of the type of imaging to be obtained (see below), a similar situation occured last year for 2014 HQ124. These were some of the best radar images ever recorded, and some of my data was used to refine the orbit for targeting on that occasion.

Image Credit: Asteroid 2014 HQ124 Radar images from Goldstone - NASA/JPL

This asteroid is twice as big (between 290 and 650 meters diameter - most astronomers are calling it about 480m) and twice as close as 2014 HQ124, so you can only imagine how good the images should be. Professional Observatories and amateur astronomers will be tracking it closely to improve the precision of the orbit as it approaches.

I was quite chuffed when tracking 2014 HQ124 that my light curve had a few bumps in it and I made the call it was "not round" which was subsequently confirmed by the radar images.

So who knows what the next two weeks will turn up? What we know at this stage is that is going to be quite bright and could be visible in binoculars. Also its speed is very fast, but its moving slowly across the images at the moment as you can see, because of the angle its approaching us at. As it makes its close approach its going to do a nice "flyby" of the Crab Nebula M1 for Northern Hemisphere viewers on Oct 29th/30th Ian Musgrave has details on his blog shortly.

So stay tuned, I'll be following it closely and providing some regular updates.

What's up with Scheila (596)

URGENT UPDATE:2011/01/01 08:00 UT - Scheila dusts off tail after Christmas Show.
Scheila's tail appears to have disappeared! I have just emailed Ernesto to see if he is in a position to confirm. Joseph Brimacombe reported on the 30th that Scheila was sporting a nice tail but had to go to 5x1200 sec at f5, so clearly it has faded.



Travelling slighly faster and a little fainter that my last image on the 13th (OK I have been on holidays....slack I know) there is no evidence of a tail in todays image. This image is a stacked image of 6x300 Sec frame stacked for movement of the comet, even when I went to 10x300 sec, still no evidence of the tail.

Peter

UPDATE: 2010/12/23
UA Catalina Sky survey have formally released a statement on (596) Scheila after it's cometary outburst on the 11th (see history below). The statement covers a review of the circumstances of discovery, and for the first time some commentary on the spectra of follow-up observations. The statement suggests that the spectral analysis so far confirms that the outburst produced a dust tail indicating re-activation of a previously dead comet made up of largely carbonaceous material.

UPDATE: 2010/12/13 UT 23:40

As mentioned below here is the 8x300 binned 1x1.



UPDATE: 2010/12/13 UT 23:30
My latest image from 13/12/2010 shows Scheila in pretty much the same configuration as it has been for the past two days.



UPDATE: 2010/12/13 UT 13:30
Latest image on (596) Scheila is going out tonight as an exclusive for Doc Newstein at Ciel et Espace in France As soon as Frank posts it I'll post a link to it here. It is again a 5x300sec image binned 2x2 this time, I'll let you be the judge but I think the tail does look a little longer, but that could be a function of it being a little higher in the sky tonight. I have another 8 frames that I am yet to process binned 1x1 and I am going to put them into a little animation. Bonsoir amis astronomie en France!!!!

UPDATE: 2010/12/13 UT 04:30
Vishnu Reddy has been reviewing some of the historical spectral data for (596) Scheila and believes the spectrum is very similar to the Tagish Lake Meteorite, and consistent with a possible MBC (main belt comet).

UPDATE: 2010/12/13 UT 00:00
Wikipedia entry for Scheila (596) has just been updated with all the articles links prompting a massive traffic surge. I love Revolver Map!


UPDATE: 2010/12/12 UT 23:00
Mike Simonsen has done some research overnight on previous Catalina plates and identified that Scheila (596) started to get a little fuzzy around the 3rd of November. Mike also discusses previous examples of Main Belt Comets that behave as asteroids before springing into life. Mike is the Development Director at the AAVSO and runs Simostronomy Blog and writes for Universe Today.

UPDATE: 2010/12/12 UT 11:00 I have finished the color run....not much more to comment on, other than the subs were probably a little too short to get much more detail. Anyway we'll see what tomorrow brings in the way of commentary from the scientists.


UPDATE: 2010/12/12 UT 09:00 Ernesto is doing another run, and I have just started a 30min colour run now to see what color we can see. In the early preview image there doesn't seem to be much in the red spectrum, but as its only a 120 sec sub...there won't be alot there anyway. [Note: reversing the post order now for easy reading.]

UPDATE: 2010/12/12 UT 07:00
Here is my first image of Scheila (596), It is still very low to the horizion, I'll try for some color later in the evening. The image is quite noisy as it was only about 25 degrees above the horizion - a bit low for quality astrophotography.

It certainly has a good little tail going there.

UPDATE 2010/12/12 05:00 UT
Some good discussion now occuring on the MPML in Yahoo Groups. Some speculation on what may have caused the "tail" to develop. Marshall Eubanks has suggested it will take a little time to determine if it is a cometary outburst or dust raised by an asteroid collision. A "minor" collision should see the dust dissipate in a few weeks, if it is a cometary outburst it should last for a more prelonged period of time. Robert Matson had a quick look at known objects in the vacinity, the nearest object 2006 HV77, according to Robert is not close enough to be in consideration as a likely suspect. Dave Herald has suggested that the chances of two known objects colliding in the asteroid belt is about the same as two objects 100th the thickness of a human hair colliding on a footbal pitch.

But it does happen...... (although in fairness to Dave's math this was an Unknown VS Unknown collision).

Scheila should be visible from New Mexico in about an hour.

UPDATE 2010/12/12 03:00 UT
I should be ableto get some images myself myself once Scheila is above the horizion in New Mexico.

UPDATE 2010/12/12 02:00 UT
So it's official Steve Larson has observed a "spiral like" cometary outburst on Scheila (596) whilst reviewing Catalina Sky Survey photos overnight. This has just been announced in CBET 2583 on the IAU site.

Amateur astronomers are now pouncing on it for for quality images. Ernesto has posted an intial set of photos in his blog. They still seem fairly raw at this stage and I'm sure he will have a stunning processed version available shortly.


Scheila (596) is a main belt asteroid that was discovered in 1906. It is a bright slow moving main belter with a Perihelion of 2.4au (which means it comes nowhere near earth). Scheila is one of the most studied asteroids, regularly tracked for occulations with other stars, much is known about its rotational period and its lightcurve has been extensively studied.

So why is it listed on the Minor Planet's confirmation page with three comments in an hour?

Sailing along at Mag 13 most asteroids that bright get picked up by the surveys pretty quickly and are quickly eliminated as known objects by the hard-working staff and processes at the MPC. Something has prompted a number of quick follow-up observations.

Astronomers doing astrometery on asteroids report RA/DEC co-ordinates with a Universal time stamp from the registered observatory (which identifies LAT/LONG of Observer). The accuracy of the position measurements are called residuals which is an RMS differential to the predicted path. The Minor Planet Center would consider rms 0.2-0.6 arcsec quality data. I myself have had data rejected by MPC (rightly so) with residuals of 4 arcsecs - usually because I have done something stupid, such as reported the time incorrectly.

Asteroids studied since 1906 don't normally show up with dodgy arcsecs residuals, because the sum total of their "arc" in this this case a many opposition highly accurate orbit is well known. (One of the observer comments refered to residuals being a bit higher than expected).

So What's up? If it was "unknown newbie" reporting data perhaps we might dismiss it.

Turning to twitter...the constant source of live action - Ernesto Guido seems animated about something and he has done alot of quality work on asteroid and comet photography and according to his twitter feed he is about to post a most fascinating image. Ernesto does great work on photos of comets, and has photographed a number of outbursts recently.

Perhaps Scheila (596) has had a little global warming and popped an icy tail? Perhaps it has had a "fender bender" with another asteroid.