APOD: The Rosette Nebula (2011 Feb 14)

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Expand view Topic review: APOD: The Rosette Nebula (2011 Feb 14)

Re: APOD: The Rosette Nebula (2011 Feb 14)

by bystander » Tue Feb 15, 2011 11:33 pm

toooldforme wrote:All this talk of age! Millions of years? I don't think the ICR or the author of this image would agree - afterall - they both KNOW the Universe is < 10,000 years old - check out the author's website . . .
Well, you came to the wrong forum if you wish to espouse that viewpoint - check out The Rules. Everybody here knows the universe is 13.7 billion years old. We don't particularly care about what the ICR thinks it knows nor are their non-scientific viewpoints welcome here. Science is discussed here.

Re: APOD: The Rosette Nebula (2011 Feb 14)

by toooldforme » Tue Feb 15, 2011 10:32 pm

All this talk of age! Millions of years? I don't think the ICR or the author of this image would agree - afterall - they both KNOW the Universe is < 10,000 years old - check out the author's website . . .

Re: APOD: The Rosette Nebula (2011 Feb 14)

by DavidLeodis » Tue Feb 15, 2011 7:55 pm

bystander wrote:Wiki says 5,200 ly with a radius of 65 ly. Several other references I found give the same figures.
Thanks bystander. :)

Re: APOD: The Rosette Nebula (2011 Feb 14)

by bystander » Tue Feb 15, 2011 3:23 pm

Wiki says 5,200 ly with a radius of 65 ly. Several other references I found give the same figures.

Re: APOD: The Rosette Nebula (2011 Feb 14)

by DavidLeodis » Tue Feb 15, 2011 2:58 pm

In the explanation it states "The Rosette Nebula spans about 100 light-years across, lies about 5000 light-years away". However, in the explanation to the APOD that is brought up through the "Rosette Nebula" link in that sentence it states the nebula is 3000 light-years away. I realise that distances can be difficult to accurately determine but it does seem to be a large difference between "3000" and "about 5000". Does anyone know what the accepted distance is? Thanks.

Re: APOD: The Rosette Nebula (2011 Feb 14)

by dougettinger » Mon Feb 14, 2011 8:55 pm

Ann wrote:
dougettinger wrote:How do astronomers tell the age of these open cluster stars in the center of the Rossette cluster ? These stars are listed as being 4 million years old which is extremely specific for cosmic time.

Doug Ettinger, Pittsburgh, PA 02/14/11
Indeed, four million years old is very specific. I don't know enough to explain how astronomers arrived at exactly that figure. I know, however, that it can't be off by too many million years.

Astronomers use color-magnitude diagrams to date clusters:
Young clusters are rich in bright blue stars. The brighter and bluer a star is, the younger it must be, because the the brighter and bluer a star is, the more massive it is, and the faster it evolves and dies.

You can see in the color-magnitude diagram that NGC 2362 contains very bright blue stars. Here is a picture of the cluster, centered on O9 supergiant Tau Canis Majoris:
Mighty Tau Canis Majoris is surrounded by a cluster of blue but not quite so massive B-type stars. You can see some reddish stars in the outskirts of the cluster, too: they are either background stars or relatively low-mass and therefore redder members of the cluster.

So how old is the Tau Canis Majoris Cluster? According to Professor Emeritus Jim Kaler, who has written several books about stars, Tau Canis Majoris itself is estimated to be five million years old - in other words, it would be one million years older than the Tau Canis Majoris cluster. See http://stars.astro.illinois.edu/sow/taucma.html

So why should the NGC 2244 be one million years younger? Well, for starters, all the bright members of this cluster are hot blue stars. Oh, but surely the brightest member of this cluster is an evolved red giant? No, because the yellow star right next to the blue ones is a foreground star and not a member of NGC 2244. As for the true members of the cluster, at least three are O-type stars. The fact that there are three O-type stars and not a single red supergiant in this cluster is in itself proof that the cluster is very young. Let's compare NGC 2244 with the famous Double Cluster in Perseus:
As you can see, there are some prominent red giants that appear to be members of the Double Cluster. Interestingly, however, Wikipedia says about the Double Cluster that NGC 884, the cluster that seems to contain all the red giants, is only 3.2 million years old and therefore younger than the Rosette Nebula Cluster. This doesn't seem right to me, particularly in view of the fact that Wikipedia also says that the neither of the two clusters of the Double Cluster contain any O-type stars.The fact that these clusters are so rich strongly suggests to me that they must originally have contained some O-type stars, which have now evolved and become cooler. The red giants could be such former O-type stars, although we might perhaps expect them to be more centrally placed in the clusters if they were the original O-type members. Anyway, I question the suggestion that NGC 884 would be only 3.2 million years old. NGC 869, the "other member of the Double cluster", clearly contains some centrally placed bright and slightly yellowish members, which may indeed be former O-type stars which have now evolved into, say, A- or F-type supergiants. NGC 869 is estimated to be 5.6 million years old, according to Wikipedia.

Please note that neither the Tau Canis Majoris cluster nor the Double Cluster are surrounded by any nebulosity. These clusters must have been born out of massive gas clouds, but these gas clouds are now completely gone. NGC 2244, on the other hand, is surrounded by the magnificent Rosette Nebula, the nebula it was born from. NGC 2244 is so young that it has not had time to "blow away" all its natal gasses. We may note, however, that the hot bright stars have "burned a hole" in the central part of the Rosette.

In short I would say that four million years seems like a reasonable age estimate for the Rosette Nebula cluster.

Ann
Thanks, Ann. Have a happy Valentines Day.

Doug Ettinger, Pittsburgh, PA

Re: APOD: The Rosette Nebula (2011 Feb 14)

by León » Mon Feb 14, 2011 7:31 pm

Nebula yesterday that 40,000 or 100,000 years, creating today's leading stars from 4,000,000 years ago and foulbrood can see from the protostars is for several million more.

Among both generate a state of incertiudumbre.

Something else, which is the phenomenon that raises a cloud of such a feature that does not exhaust its material with such a generation of stars?

Re: APOD: The Rosette Nebula (2011 Feb 14)

by bystander » Mon Feb 14, 2011 6:07 pm

Re: APOD: The Rosette Nebula (2011 Feb 14)

by Ann » Mon Feb 14, 2011 5:24 pm

neufer wrote:
Ann wrote:
P.S. Is it your birthday, neufer? Have my cosmic rose!
Thanks, Ann; although I'm not quite sure what it means when you send something that is red. :?
Point taken, Art, so have a blue rose (and a green smile) instead! :mrgreen:
Ann

Re: APOD: The Rosette Nebula (2011 Feb 14)

by Ann » Mon Feb 14, 2011 4:59 pm

dougettinger wrote:How do astronomers tell the age of these open cluster stars in the center of the Rossette cluster ? These stars are listed as being 4 million years old which is extremely specific for cosmic time.

Doug Ettinger, Pittsburgh, PA 02/14/11
Indeed, four million years old is very specific. I don't know enough to explain how astronomers arrived at exactly that figure. I know, however, that it can't be off by too many million years.

Astronomers use color-magnitude diagrams to date clusters:
Young clusters are rich in bright blue stars. The brighter and bluer a star is, the younger it must be, because the the brighter and bluer a star is, the more massive it is, and the faster it evolves and dies.

You can see in the color-magnitude diagram that NGC 2362 contains very bright blue stars. Here is a picture of the cluster, centered on O9 supergiant Tau Canis Majoris:
Mighty Tau Canis Majoris is surrounded by a cluster of blue but not quite so massive B-type stars. You can see some reddish stars in the outskirts of the cluster, too: they are either background stars or relatively low-mass and therefore redder members of the cluster.

So how old is the Tau Canis Majoris Cluster? According to Professor Emeritus Jim Kaler, who has written several books about stars, Tau Canis Majoris itself is estimated to be five million years old - in other words, it would be one million years older than the Tau Canis Majoris cluster. See http://stars.astro.illinois.edu/sow/taucma.html

So why should the NGC 2244 be one million years younger? Well, for starters, all the bright members of this cluster are hot blue stars. Oh, but surely the brightest member of this cluster is an evolved red giant? No, because the yellow star right next to the blue ones is a foreground star and not a member of NGC 2244. As for the true members of the cluster, at least three are O-type stars. The fact that there are three O-type stars and not a single red supergiant in this cluster is in itself proof that the cluster is very young. Let's compare NGC 2244 with the famous Double Cluster in Perseus:
As you can see, there are some prominent red giants that appear to be members of the Double Cluster. Interestingly, however, Wikipedia says about the Double Cluster that NGC 884, the cluster that seems to contain all the red giants, is only 3.2 million years old and therefore younger than the Rosette Nebula Cluster. This doesn't seem right to me, particularly in view of the fact that Wikipedia also says that the neither of the two clusters of the Double Cluster contain any O-type stars.The fact that these clusters are so rich strongly suggests to me that they must originally have contained some O-type stars, which have now evolved and become cooler. The red giants could be such former O-type stars, although we might perhaps expect them to be more centrally placed in the clusters if they were the original O-type members. Anyway, I question the suggestion that NGC 884 would be only 3.2 million years old. NGC 869, the "other member of the Double cluster", clearly contains some centrally placed bright and slightly yellowish members, which may indeed be former O-type stars which have now evolved into, say, A- or F-type supergiants. NGC 869 is estimated to be 5.6 million years old, according to Wikipedia.

Please note that neither the Tau Canis Majoris cluster nor the Double Cluster are surrounded by any nebulosity. These clusters must have been born out of massive gas clouds, but these gas clouds are now completely gone. NGC 2244, on the other hand, is surrounded by the magnificent Rosette Nebula, the nebula it was born from. NGC 2244 is so young that it has not had time to "blow away" all its natal gasses. We may note, however, that the hot bright stars have "burned a hole" in the central part of the Rosette.

In short I would say that four million years seems like a reasonable age estimate for the Rosette Nebula cluster.

Ann

Re: APOD: The Rosette Nebula (2011 Feb 14)

by kerberos » Mon Feb 14, 2011 3:02 pm

There are three images I see in the dust lanes at the bottom...

1. 4:00 dog leaping towards stars...possibly smaller dog head in just above first.
2. 6:00 possibly two people playing patty-cake.
3. 6:30 peacock.

someone should zoom into these areas and take some better images...like the horse head nebula

Re: APOD: The Rosette Nebula (2011 Feb 14)

by dougettinger » Mon Feb 14, 2011 2:39 pm

How do astronomers tell the age of these open cluster stars in the center of the Rossette cluster ? These stars are listed as being 4 million years old which is extremely specific for cosmic time.

Doug Ettinger, Pittsburgh, PA 02/14/11

Re: APOD: The Rosette Nebula (2011 Feb 14)

by neufer » Mon Feb 14, 2011 1:58 pm

Ann wrote:
P.S. Is it your birthday, neufer? Have my cosmic rose!
Thanks, Ann; although I'm not quite sure what it means when you send something that is red. :?

Re: APOD: The Rosette Nebula (2011 Feb 14)

by Ann » Mon Feb 14, 2011 8:58 am

Here is an unusually lovely image of the cluster, NGC 2244, which is ionizing the cosmic rose:

http://www.robgendlerastropics.com/NGC2244NMS.jpg

And here is another "cosmic rose"! :wink:

Image

Ann

P.S. Is it your birthday, neufer? Have my cosmic rose!

Re: APOD: The Rosette Nebula (2011 Feb 14)

by owlice » Mon Feb 14, 2011 7:11 am

Neufer is star stuff,
Noel is, too.
The Rosette is not really
61,538 times older than you.

Re: APOD: The Rosette Nebula (2011 Feb 14)

by NoelC » Mon Feb 14, 2011 6:53 am

neufer wrote:61,538 times older than you.
Ah yes, the age old question of age... What is it in particular that's 61,538 times older?

The nebula? Its components have certainly been around longer than that. Some might say infinitely longer, but there might be others who would bang their heads in disgust over such a thought.

The stars? Meddling minds of fine mettle pursuing a Nobel medal might want to know whether they're rich in metal.

The namesake? What's in a name? That which we call a rose; By any other color would still look as sweet.

-Noel

Re: APOD: The Rosette Nebula (2011 Feb 14)

by NoelC » Mon Feb 14, 2011 6:41 am

What a beautiful image, Brian. And I just love those diffraction spikes! ;)

-Noel

Re: APOD: The Rosette Nebula (2011 Feb 14)

by neufer » Mon Feb 14, 2011 6:12 am

Rosette is red
Rosette is blue
Young Rosette is still
61,538 times older than you.

APOD: The Rosette Nebula (2011 Feb 14)

by APOD Robot » Mon Feb 14, 2011 5:06 am

Image The Rosette Nebula

Explanation: Would the Rosette Nebula by any other name look as sweet? The bland New General Catalog designation of NGC 2237 doesn't appear to diminish the appearance of this flowery emission nebula. Inside the nebula lies an open cluster of bright young stars designated NGC 2244. These stars formed about four million years ago from the nebular material and their stellar winds are clearing a hole in the nebula's center, insulated by a layer of dust and hot gas. Ultraviolet light from the hot cluster stars causes the surrounding nebula to glow. The Rosette Nebula spans about 100 light-years across, lies about 5000 light-years away, and can be seen with a small telescope towards the constellation of the Unicorn (Monoceros).

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