APOD: Spherical Planetary Nebula Abell 39 (2012 Oct 08)

APOD Robot · Post by **APOD Robot** » Mon Oct 08, 2012 4:08 am

Spherical Planetary Nebula Abell 39

Explanation: Ghostly in appearance, Abell 39 is a remarkably simple, spherical nebula about five light-years across. Well within our own Milky Way galaxy, the cosmic sphere is roughly 7,000 light-years distant toward the constellation Hercules. Abell 39 is a planetary nebula, formed as a once sun-like star's outer atmosphere was expelled over a period of thousands of years. Still visible, the nebula's central star is evolving into a hot white dwarf. Although faint, the nebula's simple geometry has proven to be a boon to astronomers exploring the chemical abundances and life cycles of stars. In this deep image recorded under dark night skies, very distant background galaxies can be found -- some visible right through the nebula itself.

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Beyond · Post by **Beyond** » Mon Oct 08, 2012 4:13 am

oooh, and it's blue!

Ann · Post by **Ann** » Mon Oct 08, 2012 4:44 am

Indeed it's blue, and it contains galaxies, too!

Adam Block scores again!

Ann

Moonlady · Post by **Moonlady** » Mon Oct 08, 2012 6:07 am

It's very appealing! I saved another beautiful APOD for me, thanks Adam Block!

Boomer12k · Post by **Boomer12k** » Mon Oct 08, 2012 6:51 am

That is awesome. I like space bubbles and planetary nebula.

As looking in water can magnify something behind or in the water....can a bubble like that magnify on object, like a star or galaxy behind it, and by how much, if any?

I finally got out tonight, but I got chilled. I got some m27 pictures and I am going to try to put them together, rather than just use a continuous picture process...see if it helps some...

Tried to get the Helix Nebula, but could not even get it in frame, hard to find, so I settled on something I can generally get...very frustrating night...but worth it in the end.

:---[===] *

neufer · Post by **neufer** » Mon Oct 08, 2012 9:29 am

Click to play embedded YouTube video.

orin stepanek · Post by **orin stepanek** » Mon Oct 08, 2012 12:23 pm

Planetary Nebula Abell 39 does look a lot like a space bubble!

starsurfer · Post by **starsurfer** » Mon Oct 08, 2012 12:39 pm

The other very interesting thing about Abell 39 is that perfectly spherical planetary nebulae are very rare! It is hypothesized that the majority of planetary nebulae that exhibit complex morphology are either the result of a binary star or a binary central star is somehow involved. In the past few years, many new binary CS have been found in a few planetary nebulae. The other mystery is that the number of known planetary nebulae (about 3000) is much lower than theoretical estimates (the highest of which is 46 000!), many more will hopefully be found in future surveys and by amateurs!

neufer · Post by **neufer** » Mon Oct 08, 2012 1:39 pm

starsurfer wrote:
The other very interesting thing about Abell 39 is that perfectly spherical planetary nebulae are very rare! It is hypothesized that the majority of planetary nebulae that exhibit complex morphology are either the result of a binary star or a binary central star is somehow involved. In the past few years, many new binary CS have been found in a few planetary nebulae.

http://en.wikipedia.org/wiki/CS wrote:
CS may refer to:
Central Star
CinemaScope
Cowboys Stadium
Carmen Sandiego
CS "tear" gas
Carbon monosulfide (observed in the interstellar medium)
Confederate States (of America)
Colorado & Southern (Railway)
Copenhagen Suborbitals, a Danish non-profit rocket group working on the HEAT1X-TYCHO BRAHE rocket

jenee911 · Post by **jenee911** » Mon Oct 08, 2012 6:10 pm

Ah, could there be GHOSTS in space?

Looks like some "spirit orbs" I've seen!

Lordcat Darkstar · Post by **Lordcat Darkstar** » Mon Oct 08, 2012 6:42 pm

neufer wrote:
starsurfer wrote:
The other very interesting thing about Abell 39 is that perfectly spherical planetary nebulae are very rare! It is hypothesized that the majority of planetary nebulae that exhibit complex morphology are either the result of a binary star or a binary central star is somehow involved. In the past few years, many new binary CS have been found in a few planetary nebulae.
http://en.wikipedia.org/wiki/CS wrote:
CS may refer to:
Central Star
CinemaScope
Cowboys Stadium
Carmen Sandiego
CS "tear" gas
Carbon monosulfide (observed in the interstellar medium)
Confederate States (of America)
Colorado & Southern (Railway)
Copenhagen Suborbitals, a Danish non-profit rocket group working on the HEAT1X-TYCHO BRAHE rocket

Woooooh! Go Cowboys!!

Boomer12k · Post by **Boomer12k** » Mon Oct 08, 2012 10:32 pm

neufer wrote:
starsurfer wrote:
The other very interesting thing about Abell 39 is that perfectly spherical planetary nebulae are very rare! It is hypothesized that the majority of planetary nebulae that exhibit complex morphology are either the result of a binary star or a binary central star is somehow involved. In the past few years, many new binary CS have been found in a few planetary nebulae.
http://en.wikipedia.org/wiki/CS wrote:
CS may refer to:
Central Star
CinemaScope
Cowboys Stadium
Carmen Sandiego
CS "tear" gas
Carbon monosulfide (observed in the interstellar medium)
Confederate States (of America)
Colorado & Southern (Railway)
Copenhagen Suborbitals, a Danish non-profit rocket group working on the HEAT1X-TYCHO BRAHE rocket

Sir....even I...the lowly one... related the CS back to central star as it was just in the previous sentence....wasn't too difficult...

:---[===] *

zbvhs · Post by **zbvhs** » Mon Oct 08, 2012 10:39 pm

I'm a little confused. I thought sun-like stars went through a red-giant stage before collapsing to a white dwarf. The collapse blows off the star's outer layers and leaves behind a planetary nebula. Has that already happened in this case?

Ann · Post by **Ann** » Tue Oct 09, 2012 2:51 am

zbvhs wrote:I'm a little confused. I thought sun-like stars went through a red-giant stage before collapsing to a white dwarf. The collapse blows off the star's outer layers and leaves behind a planetary nebula. Has that already happened in this case?

Yes, sun-like stars will expand to become red giants before they die. They will eventually become very unstable and shed their outer atmospheres, finally leaving just their exposed cores, surrounded by a glowing shell, a planetary nebula. (They don't collapse, however.)

It is interesting, as starsurfer pointed out, that Abell 39 is so perfectly round. This suggests a much gentler "expulsion process" than is generally found in planetary nebulae. Compare Abell 39 with this (false color) picture of a famous planetary nebula, the Cat's Eye Nebula. You can see how ragged the outer parts of the nebula are, bearing witness to the "labor pains" of the progenitor of this planetary as it was going through its transitory phase.

Ann

Anthony Barreiro · Post by **Anthony Barreiro** » Tue Oct 09, 2012 6:38 pm

starsurfer wrote:... . The other mystery is that the number of known planetary nebulae (about 3000) is much lower than theoretical estimates (the highest of which is 46 000!), many more will hopefully be found in future surveys and by amateurs!

I would guess that most of them are hiding behind dust. They're very shy, you know.

Starship Asterisk*