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View Full Version here: : Animation and Trail of Bright Near-Earth Asteroid 2012 LZ1 14th June 2012


Dennis
16-06-2012, 02:21 PM
Hello,

In the early evening of 14th June 2012, a few minutes after reading about the following exciting news on Spaceweather (http://spaceweather.com/archive.php?view=1&day=14&month=06&year=2012):

“Newly-discovered asteroid 2012 LZ1 is flying past the Earth-Moon system today. At closest approach on June 14th (23:10 UT), the 500 meter-wide space rock will be 14 lunar distances (3.3 million miles) away. A team of astronomers led by Ernesto Guido photographed the incoming asteroid on June 13th”

I set up in the back garden, hoping that I would be able to record this rather large rocky object, discovered only some 2 days prior by R. H. McNaught from the Siding Spring Observatory using the 0.5-m Uppsala Schmidt telescope.

2012 LZ1 is a large Near-Earth Object (NEO) approximately 300-700 metres in size and it has been classified as a PHA (Potentially Hazardous Asteroid). PHA’s are asteroids larger than approximately 100m that can come closer to Earth than 0.05 AU.

Here is an 25 frame stack and animation showing the trail of 2012 LZ1. The rather wobbly trail is a bit of a puzzle to me right now, but is likely to have been caused by a combination of a quick and dirty set up, poor polar alignment and too short guide exposures (1 sec) which may have led to the mount chasing the seeing?

Details:

Tak Mewlon 180mm F12 with Tak x0.8 Reducer/Flattener.
SBIG ST2000XM CCD
25 frames of 60 sec exposure each
Field of View is approx. 22x17 arcmin
Image scale is 1.66 arcsec/pixel
Separate guide scope.


Cheers

Dennis

PS – the animation was generated from a median combined frame to remove the trail of 2012 LZ1. The trail frames were then blended in using CS5, to remove the background frame-to-frame variation to minimise the file size of the animated gif.

DavidU
16-06-2012, 02:23 PM
Very cool Dennis. You do the difficult stuff so well.:thumbsup:

jjjnettie
16-06-2012, 02:34 PM
:D Stunning work Dennis. As usual.
Thanks so much for sharing this with us. :)

iceman
16-06-2012, 02:43 PM
Wow, I love it when you talk technical Dennis.

As David said, you do this stuff so well.

Paul Haese
16-06-2012, 03:16 PM
Very cool animation. That asteroid is really rocketing along.

strongmanmike
16-06-2012, 03:39 PM
Yes very cool Dennis

Mike

theodog
16-06-2012, 05:46 PM
Nice one Dennis.

I must get back into this.

spacezebra
16-06-2012, 06:32 PM
Hi Dennis

Great capture. I have a question (sorry if this is a doh! moment) but why is the trail so jaggered - is this because the object is itself rotating? Interested in the physics and imaging aspects.

Just curious - happy to be berated if necessary. LOL

Cheers Petra d.

peter_4059
16-06-2012, 06:49 PM
Well done Dennis. As usual nicely captured.

Peter

h0ughy
16-06-2012, 06:50 PM
YOu're are beyond legend status Dennis - this is phenominal

Derek Klepp
16-06-2012, 06:59 PM
Good Science Dennis

Dennis
16-06-2012, 07:12 PM
Thanks for all the nice comments everyone, I’m pleased that this last minute project managed to produce some useful results.

@Petra – I think that the ragged path is a product of sloppy technique rather than a property of the asteroids motion, which should be linear. I set up in a rush and had large rubber bands supporting the weight of the CCD camera to prevent it slipping. I was also using a side by side set up and I have been plagued by auto guiding problems with this set up. The auto guider was taking guide exposures every 1 sec and then applying the corrections and I think this is what we are seeing.

My guess is that the stars came out mostly round because they are points of light rather that trails, so the oscillating tracking is kind of hidden in the “bloated” stellar disc, but becomes more amplified when the object produces a linear trail.

Cheers

Dennis

Quark
16-06-2012, 07:47 PM
A great piece of work there Dennis, a challenge well met for sure. To track this down so promptly following discovery is a most creditable effort, indeed.

Love your work.
Regards
Trevor

multiweb
16-06-2012, 07:50 PM
Great report Dennis. I also would have thought that the jagged path is related to the rotation of the body. I've seen pics and trails of tumbling satellites before giving the impression of a wobbly tail when it's in fact differences in illumination over the surface of the object.

Nico13
16-06-2012, 08:31 PM
Great to see an IIS'er caught it and did a pretty good job of it with short notice. :thumbsup:
Thanks for showing it.
Watched a bit of a report at work on Slooh.com your report equally as good.

Matt Wastell
16-06-2012, 08:57 PM
That is way cool!

gary
17-06-2012, 02:00 AM
Dennis, you have done it again. Fabulous stuff! :thumbsup:

Dennis
17-06-2012, 07:30 AM
Thanks Marc – that is an interesting observation that I hadn’t considered as I thought that the energy dynamics to sustain the tumbling of a 300-700m sized asteroid would be enormous and would have dissipated over aeons to leave a more smooth passage through the skies. Just fanciful guesswork though!:):shrug:

Cheers

Dennis

Dennis
17-06-2012, 07:34 AM
Thanks Trevor, Marc, Ken, Matt and Gary, I appreciate your comments.

Cheers

Dennis

Deeno
17-06-2012, 08:16 AM
Some really clever work!

astroron
17-06-2012, 10:33 AM
Brilliant as ever Dennis:)
Thanks for posting and keeping us in the loop
on these objects.I was going to try and observe
it but was clouded out .:(
Cheers:thumbsup: