Rigel and the Witch Head Nebula (2009 Dec 29)

Comments and questions about the APOD on the main view screen.
User avatar
APOD Robot
Otto Posterman
Posts: 4840
Joined: Fri Dec 04, 2009 3:27 am

Rigel and the Witch Head Nebula (2009 Dec 29)

Post by APOD Robot » Tue Dec 29, 2009 4:55 am

Image Rigel and the Witch Head Nebula

Explanation: Double, double toil and trouble; Fire burn, and cauldron bubble -- maybe Macbeth should have consulted the Witch Head Nebula. This suggestively shaped reflection nebula on the lower left is associated with the bright star Rigel, to its right, in the constellation Orion. More formally known as IC 2118, the Witch Head Nebula glows primarily by light reflected from Rigel. Fine dust in the nebula reflects the light. Pictured above, the blue color of the Witch Head Nebula and of the dust surrounding Rigel is caused not only by Rigel's blue color but because the dust grains reflect blue light more efficiently than red. The same physical process causes Earth's daytime sky to appear blue, although the scatterers in Earth's atmosphere are molecules of nitrogen and oxygen. Rigel, the Witch Head Nebula, and gas and dust that surrounds them lie about 800 light-years away.


User avatar
neufer
Vacationer at Tralfamadore
Posts: 18805
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: Rigel and the Witch Head Nebula (2009 Dec 29)

Post by neufer » Tue Dec 29, 2009 2:22 pm

Image
Art Neuendorffer

User avatar
geckzilla
Ocular Digitator
Posts: 9173
Joined: Wed Sep 12, 2007 12:42 pm
Location: Modesto, CA

Re: Rigel and the Witch Head Nebula (2009 Dec 29)

Post by geckzilla » Tue Dec 29, 2009 3:31 pm

Sorry neufer, your plans for using an image hosted by tripod are foiled today.
Just call me "geck" because "zilla" is like a last name.

rigelan
Science Officer
Posts: 144
Joined: Thu Aug 11, 2005 12:54 am
Location: Indianola, IA

Re: Rigel and the Witch Head Nebula (2009 Dec 29)

Post by rigelan » Tue Dec 29, 2009 5:10 pm

Looks like its my turn to say, "Hey star, nice name!"

User avatar
BMAONE23
Commentator Model 1.23
Posts: 4076
Joined: Wed Feb 23, 2005 6:55 pm
Location: California

Re: Rigel and the Witch Head Nebula (2009 Dec 29)

Post by BMAONE23 » Tue Dec 29, 2009 5:46 pm

At lease the Properties will allow you to drag out the HTTP address
http://pacek.tripod.com/WHSpage/man_in_the_moon1.gif
and see the image

User avatar
Case
Commander
Posts: 611
Joined: Sat Jun 09, 2007 10:08 pm
Location: (52°N, 06°E)

Re: Rigel and the Witch Head Nebula (2009 Dec 29)

Post by Case » Tue Dec 29, 2009 6:38 pm

Or re-upload to a real image hosting service.
Image
I, for one, like Roman numerals.

User avatar
neufer
Vacationer at Tralfamadore
Posts: 18805
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: Rigel and the Witch Head Nebula (2009 Dec 29)

Post by neufer » Tue Dec 29, 2009 6:52 pm

Thanks to everyone for all the help. :P

Image
Computer generated image of Rigel compared to the Sun (to scale)
Art Neuendorffer

GaryR
Ensign
Posts: 14
Joined: Tue Nov 10, 2009 12:54 am

Re: Rigel and the Witch Head Nebula (2009 Dec 29)

Post by GaryR » Wed Dec 30, 2009 1:40 am

neufer wrote:Thanks to everyone for all the help. :P

Image
Computer generated image of Rigel compared to the Sun (to scale)
:?: How was the diameter of Rigel measured at 800 ly distance? Anyway, your computer-generated image makes the Sun look about the size of the Earth relative to the Sun! Also, how is the size of Rigel compared with that of Betelgeuse, a red supergiant?

GaryR

User avatar
geckzilla
Ocular Digitator
Posts: 9173
Joined: Wed Sep 12, 2007 12:42 pm
Location: Modesto, CA

Re: Rigel and the Witch Head Nebula (2009 Dec 29)

Post by geckzilla » Wed Dec 30, 2009 1:53 am

Gary, if you scroll to the bottom of this page there is an illustration with Sol, Rigel, and Betelgeuse.
http://www.co-intelligence.org/newslett ... isons.html

Someone ought to do a better illustration. Somewhere along the line that one just got really poorly compressed. And actually I checked wikipedia and the relative sizes of the stars on that image seem to be wrong. Hmm.

I guess star radius guesses change a lot because there's a lot of contradictions even within Wikipedia. For instance, for Deneb the caption to the picture says Deneb is 200-300 times the radius of the sun while the chart on the right claims it is 108-114 times the sun's radius.
Just call me "geck" because "zilla" is like a last name.

User avatar
NoelC
Creepy Spock
Posts: 876
Joined: Sun Nov 20, 2005 2:30 am
Location: South Florida, USA; I just work in (cyber)space

Re: Rigel and the Witch Head Nebula (2009 Dec 29)

Post by NoelC » Wed Dec 30, 2009 5:06 am

An impressive image of that huge yet tenuous dust cloud.

I love how far amateur astrophotography has come.

-Noel