APOD: M1: The Crab Nebula (2014 Nov 21)

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Expand view Topic review: APOD: M1: The Crab Nebula (2014 Nov 21)

Re: APOD: M1: The Crab Nebula (2014 Nov 21)

by Ron-Astro Pharmacist » Sat Nov 22, 2014 1:20 am

A beautiful puff of lightning discharges alone against a black background of stark stars. Certainly number one on my list too.

Re: APOD: M1: The Crab Nebula (2014 Nov 21)

by Boomer12k » Sat Nov 22, 2014 12:19 am

Looks more like another HEART nebula nowdays....with all the detail...lots of filaments.

Awesome pic....
:---[===] *

Re: APOD: M1: The Crab Nebula (2014 Nov 21)

by hlwelborn » Sat Nov 22, 2014 12:08 am

Very beautiful !

Re: APOD: M1: The Crab Nebula (2014 Nov 21)

by geckzilla » Fri Nov 21, 2014 7:12 pm

Chris Peterson wrote:
CURRAHEE CHRIS wrote:1- why is it called a crab nebula? I dont really see the connection except for perhaps the orange coloring?
Visually, it has no color. It does, however, resemble a crab, with a dense central region and filamentous "legs". The earliest telescopic sketches show it that way.
Hmm. Interesting article about the naming of the crab which indicates the person who named it actually changed his mind later.
The Crab Nebula was first observed in modern times by John Bevis in 1731 and was subsequently rediscovered in 1758 by Charles Messier, becoming the very first Messier object. The origin of its name is ascribed to William Parsons, the third Earl of Rosse (Hester & Sankrit, 1997). While testing his 36-inch Newtonian reflecting telescope, the Earl observed and drew the following image of Messier 1:

[Drawing by Earl of Rosse]

Noting its resemblance to a crab, he so named the nebula. Four years later, after making new observations with a 72-inch telescope, the Earl revised his previous sketch of the nebula and asserted that it did not, in fact, resemble a crab, though the name stuck (Dewhirst, 1983).

Re: APOD: M1: The Crab Nebula (2014 Nov 21)

by dlw » Fri Nov 21, 2014 7:02 pm

Please pardon a naive question: why is oxygen the second most often observed spectral line? Is is more abundant or simply emitting more energy than, say, lithium or carbon?

As to "Why is it called the Crab Nebula" -- I'm from California. This is what I think a crab looks like. The Crab nebula is similar in shape to the dark red body of our crab. Commercial Dungeness crab season has just started out here, btw!!
Dungeness crab -- quite delicious!
Dungeness crab -- quite delicious!

Re: APOD: M1: The Crab Nebula (2014 Nov 21)

by geckzilla » Fri Nov 21, 2014 6:26 pm

You might also be thinking of this one, which is not a real video but an approximation by an artist. And we all know how accurate artists are. :wink: It does look reasonable enough to me, though. Looks like the Hubble mosaic was squished down with software and then played in reverse.
Click to play embedded YouTube video.

Re: APOD: M1: The Crab Nebula (2014 Nov 21)

by Chris Peterson » Fri Nov 21, 2014 3:21 pm

starsurfer wrote:
madtom1999 wrote:Has anyone made a time lapse of this? I'd imagine we've got enough images around to get a few seconds of its development?
I have seen animations of time lapse images spanning many decades that show the expansion of the supernova remnant. However I can't remember where I saw them. :cry:
Google is your friend.

Re: APOD: M1: The Crab Nebula (2014 Nov 21)

by starsurfer » Fri Nov 21, 2014 2:57 pm

madtom1999 wrote:Has anyone made a time lapse of this? I'd imagine we've got enough images around to get a few seconds of its development?
I have seen animations of time lapse images spanning many decades that show the expansion of the supernova remnant. However I can't remember where I saw them. :cry:

Re: APOD: M1: The Crab Nebula (2014 Nov 21)

by Chris Peterson » Fri Nov 21, 2014 2:42 pm

CURRAHEE CHRIS wrote:1- why is it called a crab nebula? I dont really see the connection except for perhaps the orange coloring?
Visually, it has no color. It does, however, resemble a crab, with a dense central region and filamentous "legs". The earliest telescopic sketches show it that way.

Re: APOD: M1: The Crab Nebula (2014 Nov 21)

by madtom1999 » Fri Nov 21, 2014 2:16 pm

Thanks Geckzilla - they were fun. I'd like to see how the whole nebula is growing though -we should have nigh on a hundred years of images around the place. I may have to collect a few and see if I can make a vid.

Re: APOD: M1: The Crab Nebula (2014 Nov 21)

by FloridaMike » Fri Nov 21, 2014 1:35 pm

CURRAHEE CHRIS wrote:Couple questions from a novice:

1- why is it called a crab nebula? I dont really see the connection except for perhaps the orange coloring?
I imagine that it could appear more crab like using the same equipment as used by those who named the object.

Re: APOD: M1: The Crab Nebula (2014 Nov 21)

by CURRAHEE CHRIS » Fri Nov 21, 2014 1:27 pm

Whoops- sorry- looks like there is a link to explain the 1054 documentation - appears as if Chinese astronomers witnessed it then- thank you!!!

Re: APOD: M1: The Crab Nebula (2014 Nov 21)

by CURRAHEE CHRIS » Fri Nov 21, 2014 1:26 pm

Couple questions from a novice:

1- why is it called a crab nebula? I dont really see the connection except for perhaps the orange coloring?

2- astronmers saw the phenomenon take place in 1054- is this actually documented somewhere or is it theorized/hypothesized?

Thank you!! :)

Re: APOD: M1: The Crab Nebula (2014 Nov 21)

by geckzilla » Fri Nov 21, 2014 7:57 am

madtom1999 wrote:Has anyone made a time lapse of this? I'd imagine we've got enough images around to get a few seconds of its development?
There is some remarkable imagery of the Crab's pulsar wind. I should caution you that this looks like a drop hitting the surface of some water but that's really not a good comparison for what's actually going on. You should look at some of the model animations on the Chandra website to get a better idea of what's going on. http://chandra.harvard.edu/photo/2002/0 ... tions.html
Click to play embedded YouTube video.

Re: APOD: M1: The Crab Nebula (2014 Nov 21)

by madtom1999 » Fri Nov 21, 2014 7:12 am

Has anyone made a time lapse of this? I'd imagine we've got enough images around to get a few seconds of its development?

APOD: M1: The Crab Nebula (2014 Nov 21)

by APOD Robot » Fri Nov 21, 2014 5:11 am

Image M1: The Crab Nebula

Explanation: The Crab Nebula is cataloged as M1, the first object on Charles Messier's famous 18th century list of things which are not comets. In fact, the Crab is now known to be a supernova remnant, debris from the death explosion of a massive star, witnessed by astronomers in the year 1054. This sharp, ground-based telescopic view uses narrowband data to track emission from ionized oxygen and hydrogen atoms (in blue and red) and explore the tangled filaments within the still expanding cloud. One of the most exotic objects known to modern astronomers, the Crab Pulsar, a neutron star spinning 30 times a second, is visible as a bright spot near the nebula's center. Like a cosmic dynamo, this collapsed remnant of the stellar core powers the Crab's emission across the electromagnetic spectrum. Spanning about 12 light-years, the Crab Nebula is a mere 6,500 light-years away in the constellation Taurus.

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