APOD: The Witch Head Nebula (2015 Oct 30)

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APOD: The Witch Head Nebula (2015 Oct 30)

Post by APOD Robot » Fri Oct 30, 2015 4:05 am

Image The Witch Head Nebula

Explanation: Double, double toil and trouble; Fire burn, and cauldron bubble .... maybe Macbeth should have consulted the Witch Head Nebula. A suggestively shaped reflection nebula, this cosmic crone is about 800 light-years away though. Its frightening visage seems to glare toward nearby bright star Rigel in Orion, just off the right edge of this frame. More formally known as IC 2118, the interstellar cloud of dust and gas is nearly 70 light-years across, its dust grains reflecting Rigel's starlight. In this composite portrait, the nebula's color is caused not only by the star's intense bluish light but because the dust grains scatter blue light more efficiently than red. The same physical process causes Earth's daytime sky to appear blue, although the scatterers in planet Earth's atmosphere are molecules of nitrogen and oxygen.

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Gerard foschini

Re: APOD: The Witch Head Nebula (2015 Oct 30)

Post by Gerard foschini » Fri Oct 30, 2015 4:51 am

Your title is a ghostbuster. As a Rosorch(sp?) test I saw the full figure of a ghost before I switched to see the witch's head. anyone else see the ghost? it is quite striking. Just take a distracted gaze and it will be there for you to enjoy.

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Re: APOD: The Witch Head Nebula (2015 Oct 30)

Post by Ann » Fri Oct 30, 2015 7:46 am

As a color commentator, I find the color of the Witch Head Nebula particularly interesting. And that is not primarily because the Witch Head is blue, but because it isn't very blue.

Sky Catalogue 2000.0, Volume 2, lists bright nebulas in the sky and estimates their color.The bluest nebulas are described as "VB", very blue, and the reddest ones are described as "VR", very red. The Antares nebula is described as "VR", whereas all the various Pleiades nebulas are described as "VB". The Witch Head Nebula, IC 2118, is described as "B", blue. Not "VB".

I agree. IC 2118 is like the sky of the Earth: part blue, part cloudy.
Click to play embedded YouTube video.
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Re: APOD: The Witch Head Nebula (2015 Oct 30)

Post by Ann » Fri Oct 30, 2015 7:50 am

Oh, I forgot to say that it's a great APOD, and so suitable for today! :D

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Re: APOD: The Witch Head Nebula (2015 Oct 30)

Post by Boomer12k » Fri Oct 30, 2015 10:30 am

And a great images of it to be sure. Along with the blue, indigo and violet colors...

And the laughing ghost coming out of the top of her hat! :shock:

Happy Halloween, tomorrow!

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Asterhole

Re: APOD: The Witch Head Nebula (2015 Oct 30)

Post by Asterhole » Fri Oct 30, 2015 2:24 pm

I don't know - maybe a more appropriate name for this cosmic visage coul be "Ex-Wife's Head Nebula"... :P

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Re: APOD: The Witch Head Nebula (2015 Oct 30)

Post by saturno2 » Fri Oct 30, 2015 3:03 pm

I agree with Ann, this Nebula is only blue,
it is not " blue blue " ( VB)
This image is Halloweeeeeeen :mrgreen:

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Re: APOD: The Witch Head Nebula (2015 Oct 30)

Post by starsurfer » Fri Oct 30, 2015 5:08 pm

Great image of this wonderful reflection nebula! The various background galaxies are delightful to find! :D

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Re: APOD: The Witch Head Nebula (2015 Oct 30)

Post by Ann » Fri Oct 30, 2015 5:22 pm

starsurfer wrote:Great image of this wonderful reflection nebula! The various background galaxies are delightful to find! :D
Indeed! For us northerners, the nebula is upside down :wink: , so the upper part of the picture is the southern part of the Witch Head Nebula. And there are many beautiful galaxies in the upper, that is southern, part of the image, but apparently none at all in the lower, northern part of it, in the direction of supergiant stars and major nebulas of Orion.

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Re: APOD: The Witch Head Nebula (2015 Oct 30)

Post by Ron-Astro Pharmacist » Fri Oct 30, 2015 7:03 pm

Thanks Ann. I was curious about the statement in the text about Rigel being off to the right.

http://www.belugalakeobservatory.com/ph ... a&photo=52

I like the photographer's site link as it shows in the sky where the photograph was taken for us wannabe astronomers.
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Re: APOD: The Witch Head Nebula (2015 Oct 30)

Post by hoohaw » Sat Oct 31, 2015 9:40 am

Hey, this is YESTERDAY's commentary!

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Re: APOD: The Witch Head Nebula (2015 Oct 30)

Post by Beyond » Sat Oct 31, 2015 9:41 pm

BOO!! to you all.
To find the Truth, you must go Beyond.

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Re: APOD: The Witch Head Nebula (2015 Oct 30)

Post by starsurfer » Sun Nov 01, 2015 5:55 pm

Ann wrote:
starsurfer wrote:Great image of this wonderful reflection nebula! The various background galaxies are delightful to find! :D
Indeed! For us northerners, the nebula is upside down :wink: , so the upper part of the picture is the southern part of the Witch Head Nebula. And there are many beautiful galaxies in the upper, that is southern, part of the image, but apparently none at all in the lower, northern part of it, in the direction of supergiant stars and major nebulas of Orion.

Ann
Well it's only when it's upside down that it looks like a Witch's Head!

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Re: APOD: The Witch Head Nebula (2015 Oct 30)

Post by Ann » Sun Nov 01, 2015 6:12 pm

starsurfer wrote:
Well it's only when it's upside down that it looks like a Witch's Head!
Well, "right side up" it looks like a full figure of some sort, with a slightly bear-like lowbrow head with a protruding snout, a female bosom, a short protruding arm and a windblown, diaphanous dress.

I used to think that the "right side up" figure was the Witch Head!

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