APOD: Wide Angle: The Cats Paw Nebula (2010 Apr 21)

Comments and questions about the APOD on the main view screen.
Post Reply
User avatar
APOD Robot
Otto Posterman
Posts: 5589
Joined: Fri Dec 04, 2009 3:27 am
Contact:

APOD: Wide Angle: The Cats Paw Nebula (2010 Apr 21)

Post by APOD Robot » Wed Apr 21, 2010 3:59 am

Image Wide Angle: The Cats Paw Nebula

Explanation: Nebulae are perhaps as famous for being identified with familiar shapes as perhaps cats are for getting into trouble. Still, no known cat could have created the vast Cat's Paw Nebula visible in Scorpius. At 5,500 light years distant, Cat's Paw is an emission nebula with a red color that originates from an abundance of ionized hydrogen atoms. Alternatively known as the Bear Claw Nebula or NGC 6334, stars nearly ten times the mass of our Sun have been born there in only the past few million years. Pictured above, a wide angle, deep field image of the Cat's Paw nebula was culled from the second Digitized Sky Survey.

<< Previous APODDiscuss Any APOD Next APOD >>
[/b]

Astronut

Re: APOD: Wide Angle: The Cats Paw Nebula (2010 Apr 21)

Post by Astronut » Wed Apr 21, 2010 4:03 am

I did not see anything that looked like a cat's paw to me - However, clicking onto one of those two blue circles that have a red spot with a white dot inside - thats COOL !!

User avatar
Chris Peterson
Abominable Snowman
Posts: 18595
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA
Contact:

Re: APOD: Wide Angle: The Cats Paw Nebula (2010 Apr 21)

Post by Chris Peterson » Wed Apr 21, 2010 4:18 am

Astronut wrote:I did not see anything that looked like a cat's paw to me
There are a couple of reasons for that- the very high resolution of the image, and the extreme processing to bring out faint structure. Both are common these days, and explain why the images of so many famous objects look little or nothing like their names would suggest. Those names typically describe what the objects look like visually through a telescope, or how they appeared on film years ago. If you Google the Cat's Paw Nebula, you'll find quite a few images that look a lot more like a cat's paw print than this image does. Of course, they won't show as much detail, either.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com

User avatar
bystander
Apathetic Retiree
Posts: 21592
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Re: APOD: Wide Angle: The Cats Paw Nebula (2010 Apr 21)

Post by bystander » Wed Apr 21, 2010 4:24 am

On the trail of a cosmic cat
http://asterisk.apod.com/vie ... 29&t=18195

biddie67
Science Officer
Posts: 483
Joined: Sun Jan 31, 2010 9:44 am
Location: Possum Hollow, NW Florida

Re: APOD: Wide Angle: The Cats Paw Nebula (2010 Apr 21)

Post by biddie67 » Wed Apr 21, 2010 8:26 am

Thanks for the additional link above ....

kviers

Re: APOD: Wide Angle: The Cats Paw Nebula (2010 Apr 21)

Post by kviers » Wed Apr 21, 2010 11:37 am

Ionized hydrogen would be a proton stripped of its electron. How does such a cloud of positive charge maintain and form under the pressure of all that electromagnetic repulsion?

Paul Douglas
Asternaut
Posts: 6
Joined: Wed Nov 09, 2005 6:34 pm

Re: APOD: Wide Angle: The Cats Paw Nebula (2010 Apr 21)

Post by Paul Douglas » Wed Apr 21, 2010 1:31 pm

Am I correct that all the thousands of points of light are stars in our Milky Way galaxy that we are looking through to see this nebula?

dduggan47
Ensign
Posts: 27
Joined: Thu Nov 15, 2007 12:41 pm

Re: APOD: Wide Angle: The Cats Paw Nebula (2010 Apr 21)

Post by dduggan47 » Wed Apr 21, 2010 2:05 pm

Chris Peterson wrote:
Astronut wrote:I did not see anything that looked like a cat's paw to me
There are a couple of reasons for that- the very high resolution of the image, and the extreme processing to bring out faint structure. Both are common these days, and explain why the images of so many famous objects look little or nothing like their names would suggest. Those names typically describe what the objects look like visually through a telescope, or how they appeared on film years ago. If you Google the Cat's Paw Nebula, you'll find quite a few images that look a lot more like a cat's paw print than this image does. Of course, they won't show as much detail, either.
I can see the cat's paw if I look for it, but what pops out at me is a skull facing left in the picture.

Jordan

Re: APOD: Wide Angle: The Cats Paw Nebula (2010 Apr 21)

Post by Jordan » Wed Apr 21, 2010 2:14 pm

No known cat? Are you implying the possibility of a cat millions of lightyears long? Because I'd hate to be tasked with cleaning its litter. :D

User avatar
Chris Peterson
Abominable Snowman
Posts: 18595
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA
Contact:

Re: APOD: Wide Angle: The Cats Paw Nebula (2010 Apr 21)

Post by Chris Peterson » Wed Apr 21, 2010 2:20 pm

kviers wrote:Ionized hydrogen would be a proton stripped of its electron. How does such a cloud of positive charge maintain and form under the pressure of all that electromagnetic repulsion?
There are at least two factors to consider. First, you have gravitational forces holding the cloud together. It isn't just hydrogen, but various other gases and dust, as well. Second, you need to think about what it means to see the emission spectrum of ionized hydrogen. The light is produced when the hydrogen proton recaptures a free electron, and it drops back to a low energy level. The ionization-relaxation cycle has some lifetime- pretty short, I'd guess. At any one instant, only some of the hydrogen atoms are ionized. It is probably not quite correct to think of this as a cloud of ionized hydrogen, as opposed to a cloud of hydrogen that is undergoing ionization and relaxation continuously.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com

Ted Judah

Re: APOD: Wide Angle: The Cats Paw Nebula (2010 Apr 21)

Post by Ted Judah » Wed Apr 21, 2010 3:54 pm

There are two bright stars in this image. Below the one on the right there is an asterism of about 8 stars all in a row. I've never seen such a line-up before. What are the chances for seeing such an asterism as viewed from Earth I wonder?

User avatar
owlice
Guardian of the Codes
Posts: 8406
Joined: Wed Aug 04, 2004 4:18 pm
Location: Washington, DC

Re: APOD: Wide Angle: The Cats Paw Nebula (2010 Apr 21)

Post by owlice » Wed Apr 21, 2010 4:16 pm

I was looking at the large image pretty closely last night and noticed a number of asterisms of stars all in a row ranging from 7-9 stars. Once I saw the first one, others started catching my notice.
A closed mouth gathers no foot.

User avatar
bystander
Apathetic Retiree
Posts: 21592
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Re: APOD: Wide Angle: The Cats Paw Nebula (2010 Apr 21)

Post by bystander » Wed Apr 21, 2010 4:17 pm

Paul Douglas wrote:Am I correct that all the thousands of points of light are stars in our Milky Way galaxy that we are looking through to see this nebula?
Yes, those are stars in the Milky Way between us and the nebula. The Cat's Paw is also in the Milky Way.
Ted Judah wrote:What are the chances for seeing such an asterism as viewed from Earth I wonder?
You are seeing it as viewed from Earth.

User avatar
orin stepanek
Plutopian
Posts: 8200
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: APOD: Wide Angle: The Cats Paw Nebula (2010 Apr 21)

Post by orin stepanek » Wed Apr 21, 2010 9:35 pm

Astronut wrote:I did not see anything that looked like a cat's paw to me
I thought it looked like a cat's paw. From the underside; with all the toes showing. :?
Orin

Smile today; tomorrow's another day!

Post Reply