Animation and Trail of Bright Near-Earth Asteroid 2012 LZ1 14th June 2012

[Dennis]

Hello,

In the early evening of 14th June 2012, a few minutes after reading about the following exciting news on Spaceweather:

“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 (Dave)]

Very cool Dennis. You do the difficult stuff so well.

[jjjnettie (Jeanette)]

Stunning work Dennis. As usual.
Thanks so much for sharing this with us.

[iceman (Mike)]

Wow, I love it when you talk technical Dennis.

As David said, you do this stuff so well.

[Paul Haese]

Very cool animation. That asteroid is really rocketing along.

[strongmanmike (Michael)]

Yes very cool Dennis

Mike

[theodog (Jeff)]

Nice one Dennis.

I must get back into this.

[spacezebra (Petra)]

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 (Peter)]

Well done Dennis. As usual nicely captured.

Peter

[h0ughy (David)]

YOu're are beyond legend status Dennis - this is phenominal

[Derek Klepp]

Good Science Dennis

[Dennis]

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 (Trevor)]

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 (Marc)]

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 (Ken)]

Great to see an IIS'er caught it and did a pretty good job of it with short notice.
Thanks for showing it.
Watched a bit of a report at work on Slooh.com your report equally as good.

[Matt Wastell (Matt)]

That is way cool!

[gary]

Dennis, you have done it again. Fabulous stuff!

[Dennis]

Originally Posted by multiweb

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.

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!

Cheers

Dennis

[Dennis]

Thanks Trevor, Marc, Ken, Matt and Gary, I appreciate your comments.

Cheers

Dennis

[Deeno]

Some really clever work!