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APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Mon Oct 29, 2012 6:23 pm
by APOD Robot
Planetary Nebula PK 164 +31.1
Explanation: Is this what will become of our Sun? Quite possibly. The bubble of expanding gas
pictured above is the planetary nebula PK 164 +31.1, the remnants of the atmosphere of a Sun-like star expelled as its supply of fusion-able core hydrogen became depleted. Visible near the center of
the nebula is what remains of the core itself -- a blue-hot white dwarf star. This particularly photogenic
planetary nebula shows intricate shells of gas likely expelled at different times toward the end the star's demise, and whose structure is not fully understood. This deep image of PK 164 +31.1 from the
Calar Alto Observatory in
Spain shows many other stars from our own
Milky Way Galaxy as well as
several galaxies far in the distance.
PK 164 +31, also known as
Jones-Emberson 1, lies about 1,600 light years away toward the constellation of the Wildcat (
Lynx). Due to its faintness (
magnitude 17) and
low surface brightness, the object is only visible with a good-sized telescope. Although the
expanding nebula will fade away over the next few thousand years, the
central white dwarf may well survive for billions of years -- to when our universe may be a
very different place.
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Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Tue Oct 30, 2012 1:46 am
by bystander
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Tue Oct 30, 2012 3:03 am
by owlice
Today's APOD can be found
here.
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Tue Oct 30, 2012 4:35 am
by Beyond
From the link-->very different place<-->Timeline.net (future conditions beyond 10,000 AD)
All i have to say is ... Promises, promises.
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Tue Oct 30, 2012 4:46 am
by Ann
I can't help noticing the fact that I picked this very picture
just a few days ago to illustrate the concept that "white dwarfs" aren't usually white! Check out the fourth post from the bottom in the thread I linked to. In that post, I wrote:
Check out
this picture of a planetary nebula. Note the very blue color of the central star.
The reason why I picked this picture was, of course, that it so beautifully demonstrates the blue color of basically all central stars of planetary nebulae. Of course I also agree with the caption of today's APOD, which said:
This particularly photogenic planetary
It is certainly very photogenic! And the actual image is wonderful. There is a treasure trove of details in it, like the intricate structure of the nebula itself, with its multiple shells, as well as all those background galaxies, one of which is actually seen in the central "emptiness" of the planetary nebula!
The seemingly "empty" central part of the planetary is indeed
almost empty. Most of the gas has been cleared away from this space by the fierce radiation of the super-hot central star. The faint blue-green light which is seen inside this "cavity" is so-called "forbidden" OIII emission. A near-vacuum close to a super-hot star is the perfect place for a few scattered oxygen ions to emit this blue-green light.
I must say, finally, that I think it's a joy to see such a richly-hued "true-color" RGB image of a planetary nebula.
When I picked this nebula for my post a few days ago, I searched for pictures of planetaries which would actually show that the central star is blue. This one was the first one I found.
Ann
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Tue Oct 30, 2012 11:14 am
by BDanielMayfield
Now, that's a REAL blue dwarf. To avoid confussion and consternation in my unimportant opinion this term should be reserved for blue stars in the broader "white dwarf" sequence.
Bruce
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Tue Oct 30, 2012 2:26 pm
by drollere
so fix the server already. or announce your new permanent URL.
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Tue Oct 30, 2012 2:30 pm
by Chris Peterson
drollere wrote:so fix the server already. or announce your new permanent URL.
Screen shot 2012-10-30 at 7.24.27 AM.png
Maybe you live in a bubble. So just for your information, there's a rather large and destructive storm thrashing the part of the U.S. where the APOD server resides, and I expect getting that machine back online isn't really a big priority just at the moment. If you truly can't live without APOD for a couple of days, access one of the mirror sites.
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Tue Oct 30, 2012 2:35 pm
by bystander
Chris Peterson wrote:drollere wrote:so fix the server already. or announce your new permanent URL.
Screen shot 2012-10-30 at 7.24.27 AM.png
Maybe you live in a bubble. So just for your information, there's a rather large and destructive storm thrashing the part of the U.S. where the APOD server resides, and I expect getting that machine back online isn't really a big priority just at the moment. If you truly can't live without APOD for a couple of days, access one of the mirror sites.
http://asterisk.apod.com/viewtopic.php?f=28&t=29890
He obviously does live in a bubble,
antwrp.gsfc.nasa.gov/apod hasn't been the permanent URL for
APOD for some time now.
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Tue Oct 30, 2012 2:41 pm
by owlice
drollere wrote:so fix the server already. or announce your new permanent URL.
Screen shot 2012-10-30 at 7.24.27 AM.png
Goddard Space Flight Center's servers, including the APOD servers, were shut down in anticipation of possible power problems due to Hurricane Sandy.
http://asterisk.apod.com/viewtopic.php? ... 33#p186533
A prudent action, given the power of this storm.
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Tue Oct 30, 2012 3:43 pm
by neufer
APOD Robot wrote:
The bubble of expanding gas
pictured above is the planetary nebula PK 164 +31.1, the remnants of the atmosphere of a Sun-like star expelled as its supply of
fusion-able core hydrogen became depleted.
BDanielMayfield wrote:
To avoid confussion [sic] and consternation in my unimportant opinion this term should be reserved for blue stars in the broader "white dwarf" sequence.
http://en.wikipedia.org/wiki/Stern_%28magazine%29 wrote:
<<
Stern (English: "
Star") is a weekly news magazine published in Germany. Internationally, it is most famous for publishing the Hitler Diaries in 1983. These diaries were published in the 25 April edition, but they were soon revealed by scientific testing to be forged. This debacle led to the resignation of the magazine's editors and a major scandal that is still seen as a low point in German journalism.>>
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Tue Oct 30, 2012 5:07 pm
by jim johnson
Looking through planetary nebula photogalleries, one is struck by how many appear to have the morphology of two funnels tip-to-tip, expanding outward along the funnels' central axis, when viewed from the side or obliquely from the side. The Red Square Nebula seems to be what one would expect to see if the viewpoint were centered on the central star and the axis were in a plane normal to our line-of-sight. In that case, the limbs of spheres (bubbles) and any disk structures viewed from the side are all straight lines, with little visible evidence that they may contain circular aspects to their shapes.
Might the viewpoint from which this PK 164 +31.1 nebula is seen be almost axial, wherein the "clear" area within a funnel morphology's interior allows a good view of the central binary? Looking down the barrel of the funnel, so to speak, with the higher-energy radiating surfaces looking like circular or elliptical shapes? As an architect, this seems a simple rotational viewpoint solution.
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Tue Oct 30, 2012 9:37 pm
by emc
Beautiful picture!
I haven’t been through it all but I am very much enjoying the link destination from “very different place”. It is fun to think about the future and funner when astronomers and scientists do it! Thanks for this link!
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Tue Oct 30, 2012 11:12 pm
by LocalColor
Good to see you back online. Hope all survived the storm OK.
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Wed Oct 31, 2012 2:16 am
by JuanAustin
i think i understood what mr johnson was saying, but doesn't explain why the star's surface is sluffed off with an open hole on either side. shouldn't the surface be thrown off equally in thinkness all over the star with no holes or is it directly due to magnetic fields at the two poles of the star that keep the two open holes on either side of the planetary nebula? are the magnetic fields still retained and as strong or stronger once the star's surface has expanded out to the space around it?
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Wed Oct 31, 2012 2:23 am
by geckzilla
The way I understand it, it only looks like the center is a hole because the entire thing is very tenuous. Only around the edges where the bubble is thickest can we see the structures clearly. Otherwise, there sure are a lot of cylindrical planetary nebulas which happen to be pointed straight at us.
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Wed Oct 31, 2012 2:43 am
by neufer
geckzilla wrote:
The way I understand it, it only looks like the center is a hole because the entire thing is very tenuous. Only around the edges where the bubble is thickest can we see the structures clearly. Otherwise, there sure are a lot of cylindrical planetary nebulas which happen to be pointed straight at us.
The cylindrical planetary nebulae which just happen to be pointed
more or less at us have the best Public Relations.
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Wed Oct 31, 2012 3:57 am
by Ann
Today's APOD is a generally very fine image, but I love it because of its "true-color RGB" appearance.
As for the montage of pictures of planetaries taken with the Hubble Space Telescope, I find their colors confusing.
Ann
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Wed Oct 31, 2012 4:10 pm
by starsurfer
Ann wrote:
Today's APOD is a generally very fine image, but I love it because of its "true-color RGB" appearance.
Ann
Your comment about loving this image because it's RGB makes me so happy! I could hug you!
I absolutely love true colour images of planetary nebulae and I don't like the colours in false colour professional images although I do love their high spatial resolution and detail.
This has been one of my favourite planetary nebulae for some time and I especially find the intensely blue white dwarf enchanting!
The other remarkable thing is that the gas is so thin that you can see distant galaxies through it! How cool is that?!
Also I'm particularly pleased that APOD keep featuring planetary nebulae lately, I could hug owlice!
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Wed Oct 31, 2012 10:44 pm
by owlice
starsurfer, I'm sorry to have to disabuse you of the idea... I have nothing to do with what images are selected for APOD! Thank you for the compliment, but APOD is created solely by Jerry T. Bonnell and Robert J. Nemiroff (rjn on Asterisk). See #16 on
this APOD FAQ page.
Re: APOD: Planetary Nebula PK 164 +31.1 (2012 Oct 30)
Posted: Sun Nov 04, 2012 1:48 pm
by starsurfer
owlice wrote:starsurfer, I'm sorry to have to disabuse you of the idea... I have nothing to do with what images are selected for APOD! Thank you for the compliment, but APOD is created solely by Jerry T. Bonnell and Robert J. Nemiroff (rjn on Asterisk). See #16 on
this APOD FAQ page.
Yes I know but I would much rather give you a big warm hug!
