APOD: The Broad Tail of PanSTARRS (2013 Mar 30)

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APOD: The Broad Tail of PanSTARRS (2013 Mar 30)

Post by APOD Robot » Sat Mar 30, 2013 4:05 am

Image The Broad Tail of PanSTARRS

Explanation: For northern hemisphere skygazers, fading Comet PanSTARRS (C/2011 L4) still hangs above the western horzion, after sunset but before moonrise in the coming days. Its perspective from planet Earth continues to reveal the comet's broad dust tail. This long exposure tracking the comet, made on March 21, has been enhanced to show remarkable, subtle striations in PanSTARRS' tail. Place your cursor over the image (or click here) to show an overlay of the dust tail with a model network of synchrones and syndynes. Synchrones (long dashed lines) trace the location of dust grains released from the comet nucleus at the same time and with zero velocity. The successive synchrone lines shown are separated by 1 day and start at the bottom, 10 days before the comet's March 10 perihelion passage. Syndynes (solid lines) show the location of dust grains of the same size, also released with zero velocity. Dust grains 1 micron wide lie along the upper syndyne. The grain width increases counterclockwise to 500 micron wide grains along the syndyne nearly parallel to the comet's orbit (short dashed line through the nucleus location). In the model, forces acting on the dust grains were assumed to be gravity and the pressure of sunlight. The periodic striations in PanSTARRS' tail seem to closely follow the model synchrone lines.

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Re: APOD: The Broad Tail of PanSTARRS (2013 Mar 30)

Post by Beyond » Sat Mar 30, 2013 4:35 am

A 4-million kilometer wide tail :?: Peacocks will be envious :!: :lol2:
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Re: APOD: The Broad Tail of PanSTARRS (2013 Mar 30)

Post by donalgary » Sat Mar 30, 2013 5:46 am

Why do all the synchrones meat at a point?
It would seem that they should end at points spaced by the daily apparent motion of the comet.

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Re: APOD: The Broad Tail of PanSTARRS (2013 Mar 30)

Post by Boomer12k » Sat Mar 30, 2013 5:48 am

Nice close up picture. Very powerful.

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Re: APOD: The Broad Tail of PanSTARRS (2013 Mar 30)

Post by Dense One » Sat Mar 30, 2013 7:10 am

OK OK OK__I have been going outside after sunset for well over the past week--I so far have seen NOTHING
How about a actual direction heading of view and an angle about the horizon and a good time West Coast Los Angeles--but I go way outside of city lights--I still aint seen it to try to see this thing? I am NON ASTRONAMICAL

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Re: APOD: The Broad Tail of PanSTARRS (2013 Mar 30)

Post by Beluga » Sat Mar 30, 2013 9:18 am

Why are there striations? are they an indication of a rotation of the comet?

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Re: APOD: The Broad Tail of PanSTARRS (2013 Mar 30)

Post by Case » Sat Mar 30, 2013 10:13 am

Dense One wrote:I have been going outside after sunset for well over the past week--I so far have seen NOTHING. How about a actual direction heading of view and an angle about the horizon and a good time West Coast Los Angeles--but I go way outside of city lights--I still aint seen it to try to see this thing? I am NON ASTRONAMICAL
Try tonight around 19.50 h, looking roughly NW (Az 307°) and only about 9° above the horizon. Bring binoculars.
Before that time it may not be dark enough, and after that time the comet comes even closer to the horizon, disappearing below it around 20.45.
Image
Last edited by Case on Sat Mar 30, 2013 10:26 am, edited 1 time in total.

Tsap

Re: APOD: The Broad Tail of PanSTARRS (2013 Mar 30)

Post by Tsap » Sat Mar 30, 2013 11:21 am

I wonder why startrails on the picture are with different directions?

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Re: APOD: The Broad Tail of PanSTARRS (2013 Mar 30)

Post by fausto.lubatti » Sat Mar 30, 2013 12:56 pm

Amazing!

186272sec

Re: APOD: The Broad Tail of PanSTARRS (2013 Mar 30)

Post by 186272sec » Sat Mar 30, 2013 2:19 pm

Beluga wrote:Why are there striations? are they an indication of a rotation of the comet?
I like your train of thought. One portion of the comet nucleus releasing more volatiles indicating a period of rotation.

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Re: APOD: The Broad Tail of PanSTARRS (2013 Mar 30)

Post by Redbone » Sat Mar 30, 2013 2:49 pm

Synchrones (long dashed lines) trace the location of dust grains released from the comet nucleus at the same time and with zero velocity

Zero velocity relative to the Sun.


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Re: APOD: The Broad Tail of PanSTARRS (2013 Mar 30)

Post by BobStein-VisiBone » Sat Mar 30, 2013 3:46 pm

186272sec wrote:
Beluga wrote:Why are there striations? are they an indication of a rotation of the comet?
I like your train of thought. One portion of the comet nucleus releasing more volatiles indicating a period of rotation.
Getting on board both your trains. Thinking of a rotating two-liter bottle of diet coke with fresh mentos inserted.
donalgary wrote:Why do all the synchrones meet at a point?
It would seem that they should end at points spaced by the daily apparent motion of the comet.
This puzzles me too. Do the synchrone lines apparently intersecting at the comet imply there are particles that never escape the gravity of the comet? The "youngest" plume of ejecta -- the rightmost dashed synchrone line -- seems to have formed suddenly. Then the later plumes lazily drift to the left from the pressure of sunlight, with the heavier grains falling back to the comet.

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Re: APOD: The Broad Tail of PanSTARRS (2013 Mar 30)

Post by ta152h0 » Sat Mar 30, 2013 6:46 pm

gwt to do this again in a month ( or sooner ) with Comet Lemmon
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Re: APOD: The Broad Tail of PanSTARRS (2013 Mar 30)

Post by Sam » Sat Mar 30, 2013 7:19 pm

Lots of information in the text today - I now have a better understanding of: EM waves and their interactions with charged particles, syndynames and synchrones, and particle sizes. Thanks! :D
"No avian society ever develops space travel because it's impossible to focus on calculus when you could be outside flying." -Randall Munroe

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