Thursday, October 15, 2015

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.


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