Starship Asterisk*

[quote="Wolf kotenberg"]must be supernovae remnant week at APOD. Easy chair + ice cold one + APOD = an insignificant one salutes you[/quote]
room temp one not for you?

must be supernovae remnant week at APOD. Easy chair + ice cold one + APOD = an insignificant one salutes you

[quote="Dick Stacy"]If the parent star was spherical, why isn't the nebula ?[/quote]

Non-sphericle elements include the axis of rotation of the parent star, apparently the plane the two stars orbit each other in, the magnetic poles of one or both stars and maybe more.

If the parent star was spherical, why isn't the nebula ?

[quote="orin stepanek"]

Kind of like looking down a barrel. The opening is pointed right toward us! 8-)[/quote]
[list]But aren't we are pointing the barrel of a telescope at Shapley 1 :?:
[youtube]http://www.youtube.com/watch?v=oVETLf0_i2w[/youtube][/list]

I hope these help! 8-)
[url]http://www.google.com/search?q=planetary+nebula+pictures&hl=en&client=firefox-a&hs=CXf&sa=X&rls=org.mozilla:en-US:official&channel=s&biw=800&bih=410&prmd=ivns&tbm=isch&tbo=u&source=univ&ei=nnNKTvfvBIi3sQLk-_zmCA&ved=0CBsQsAQ[/url]

viewed sideways on would it look like a barrel () or a diabolo ><

Is the matter expelled at right angles to the axis of rotation of the old star? or magnetic axis ? clearly we are all wanting to know, and presumably there are all different orientations of these some appearing at right angle to our line of sight and the ones like this are purely coincidental

Kind of like looking down a barrel. The opening is pointed right toward us! 8-)
[img2]http://www.eso.org/public/archives/images/medium/potw1131a.jpg[/img2]

[quote="Georges'assistant"]Why is the center open ?
All these planetary nebulas seems like shorts cylinders with the axis orieted to us.
Are they really cylindres with the open side looking to us?
Or are they spheres that look thin in the center and with more depth in the peripheral circle ?
Thanks.[/quote]

Well, according to [url=http://www.eso.org/public/images/potw1131a/]bystander's link above[/url] we're looking through a donut. And don't ask me how the cloud got into the shape of a donut but clearly magnetic fields can do some strange seeming things.

Why is the center open ?
All these planetary nebulas seems like shorts cylinders with the axis orieted to us.
Are they really cylindres with the open side looking to us?
Or are they spheres that look thin in the center and with more depth in the peripheral circle ?
Thanks.

Why is this structure described as "annular"? Isn't it better described as a "bubble"? After all, space (and this object) is 3-dimensional.

Jumpin' Jupiter!! A relative of HAL.

[url=http://www.eso.org/public/images/potw1131a/][b][i]ESO: Smoke Signals in Space[/i][/b][/url]
[b][i] http://asterisk.apod.com/viewtopic.php?f=29&t=24661 [/i][/b]

[float=left][img]http://www.foodclipart.com/food_clipart_images/donuts_0071-0902-0318-1215_SMU.jpg[/img][/float][quote="APOD Robot"][url=http://apod.nasa.gov/apod/ap110816.html][img]http://apod.nasa.gov/apod/calendar/S_110816.jpg[/img] [size=150]Shapley 1: An Annular Planetary Nebula[/size][/url]

[b] Explanation: [/b] What happens when a star runs out of [url=http://hyperphysics.phy-astr.gsu.edu/hbase/astro/astfus.html]nuclear fuel[/url]? For stars about the mass of our Sun, the center condenses into a [url=http://apod.nasa.gov/apod/ap000910.html]white dwarf[/url] while the outer atmospheric layers are expelled into space and appear as a [url=http://en.wikipedia.org/wiki/Planetary_nebula]planetary nebula[/url]. This particular [url=http://www.noao.edu/jacoby/pn_gallery.html]planetary nebula[/url], [url=http://www.eso.org/public/images/potw1131a/]pictured above[/url] and designated [url=http://www.aao.gov.au/images/captions/aat095.html]Shapley 1[/url] after the famous astronomer [url=http://antwrp.gsfc.nasa.gov/diamond_jubilee/debate_1920.html]Harlow Shapley[/url], has a very apparent [url=http://msscoventry.freehostia.com/Games/HungaRings/HungaRings.htm]annular ring[/url] like structure. Although some of [url=http://apod.nasa.gov/apod/planetary_nebulae.html]these nebulas[/url] appear like planets on the sky (hence their name), they actually surround stars far outside [url=http://apod.nasa.gov/apod/ap990505.html]our Solar System[/url].[/quote]

[url=http://apod.nasa.gov/apod/ap110816.html][img]http://apod.nasa.gov/apod/calendar/S_110816.jpg[/img] [size=150]Shapley 1: An Annular Planetary Nebula[/size][/url]

[b] Explanation: [/b] What happens when a star runs out of [url=http://hyperphysics.phy-astr.gsu.edu/hbase/astro/astfus.html]nuclear fuel[/url]? For stars about the mass of our Sun, the center condenses into a [url=http://apod.nasa.gov/apod/ap000910.html]white dwarf[/url] while the outer atmospheric layers are expelled into space and appear as a [url=http://en.wikipedia.org/wiki/Planetary_nebula]planetary nebula[/url]. This particular [url=http://www.noao.edu/jacoby/pn_gallery.html]planetary nebula[/url], [url=http://www.eso.org/public/images/potw1131a/]pictured above[/url] and designated [url=http://www.aao.gov.au/images/captions/aat095.html]Shapley 1[/url] after the famous astronomer [url=http://antwrp.gsfc.nasa.gov/diamond_jubilee/debate_1920.html]Harlow Shapley[/url], has a very apparent [url=http://msscoventry.freehostia.com/Games/HungaRings/HungaRings.htm]annular ring[/url] like structure. Although some of [url=http://apod.nasa.gov/apod/planetary_nebulae.html]these nebulas[/url] appear like planets on the sky (hence their name), they actually surround stars far outside [url=http://apod.nasa.gov/apod/ap990505.html]our Solar System[/url].

[b][table][tr][td=left][url=http://asterisk.apod.com/discuss_apod.php?date=110815]<< Previous APOD[/url][/td][td=center][url=http://asterisk.apod.com/viewforum.php?f=9]Discuss Any APOD[/url][/td] [td=right][url=http://asterisk.apod.com/discuss_apod.php?date=110817]Next APOD >>[/url][/td][/tr][/table][/b]