M97: The Owl Nebula (APOD 2009 May 15)

Comments and questions about the APOD on the main view screen.
Post Reply
User avatar
neufer
Vacationer at Tralfamadore
Posts: 18805
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

M97: The Owl Nebula (APOD 2009 May 15)

Post by neufer » Fri May 15, 2009 12:01 pm

http://apod.nasa.gov/apod/ap090515.html

OK, guys, just WHO'S idea was this one?

(Coincidence? ... I don't think so.)
Art Neuendorffer

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

Re: M97: The Owl Nebula (APOD 2009 May 15)

Post by orin stepanek » Fri May 15, 2009 12:54 pm

Hi Art! That's not the one on the $1? :wink:

Orin
Orin

Smile today; tomorrow's another day!

User avatar
bystander
Apathetic Retiree
Posts: 21579
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Re: M97: The Owl Nebula (APOD 2009 May 15)

Post by bystander » Fri May 15, 2009 1:18 pm


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

Re: M97: The Owl Nebula (APOD 2009 May 15)

Post by neufer » Fri May 15, 2009 3:15 pm

Thanks for helping me spread the word! , Art Neuendorffer
-----------------------------------------------------------------------
Image
Note the upside down SPIDER (Cassiopeia?) on Woodsy's belt buckle!
------------------------------------------------------
MESSIER 97 : http://apod.nasa.gov/apod/ap090515.html
http://www.delphes.net/messier/m/m097.html wrote:
<<The Owl Nebula MESSIER 97 (M97, NGC 3587) is one of the fainter objects in Messier's catalog. It is one of the four planetary nebulae in that catalog, and situated in constellation Ursa Major.

M97 was discovered by Pierre Méchain on February 16, 1781. In his description of this object, Charles Messier also mentions two other nebulous objects that he (and Méchain) have seen at about the same time, but which he had not added in his printed catalog version of 1781 (in the Connoissance des Temps for 1784). As the description is obvious and he added positions by hand in his personal copy, as well as descriptions in his manuscript personal pre-print version, we now know that he had observed the objects M108 and M109. Admiral William H. Smyth first classified it as planetary nebulae in 1844. The name "Owl Nebula" goes back to Lord Rosse, who first used it in 1848; see his drawing.

Image

In 1866, William Huggins recognized its nature as a gaseous nebula from the observation of its spectrum, where he discovered two spectral lines.

M97 is one of the more complex planetary nebulae. Its appearance has been interpreted as that of a cylindrical torus shell (or globe without poles), viewed oblique, so that the projected matter-poor ends of the cylinder correspond to the owl's eyes. This shell is enveloped by a fainter nebula of lower ionization. The mass of the nebula has been estimated to amount 0.15 solar masses, while the 16 mag central star is believed to be of about 0.7 solar masses. Its dynamical age is about 6,000 years. (from Stephen J. Hynes, Planetary Nebulae).

As often for planetary nebulae, the Owl is significantly brighter visually (Machholz: 9.7 mag, Hynes: 9.9 mag) than photographically (about 12.0 mag), as most light is emitted in one green spectral line. Its distance is uncertain; the Sky Catalog 2000 has 1,300 light years (400 pc), I.S. Shklovsky 1,430, O'Dell and Kohoutek independently found 1,600 in the early 1960s, Cudworth (1974) 2,600 (our value), Becvar's Atlas Coeli Catalog 7,460, Voroncov-Vel'jaminov published 8,150, Kenneth Glyn Jones gives 10,000, and Kaufmann has 12,000 light years.

The DSSM image of M97 reveals that in the background of this nebula, there are several small nebulous objects, most probably very distant galaxies, the brightest of these objects being superimposed by the brighter star above and slightly left of M97. This brightest background object can be found on many larger-field exposures of the Owl Nebula.>>
Last edited by neufer on Sat May 16, 2009 12:50 pm, edited 1 time in total.
Art Neuendorffer

brett_w7
Asternaut
Posts: 9
Joined: Wed Apr 29, 2009 5:55 pm

Re: M97: The Owl Nebula (APOD 2009 May 15)

Post by brett_w7 » Sat May 16, 2009 4:22 am

Maybe a hominid civilization manipulating their planetary nebula to point at the Sun in the shape of a hominid???

User avatar
DavidLeodis
Perceptatron
Posts: 1169
Joined: Mon May 01, 2006 1:00 pm

Re: M97: The Owl Nebula (APOD 2009 May 15)

Post by DavidLeodis » Sat May 16, 2009 11:39 am

It is a fascinating image and I do see a resemblence to an owl.

The page brought up through the "cataloged as M97" link in the explanation has a link to 'Lord Rosse's drawings of M97, the Owl Nebula'. That is a quite an amazing drawing, though I think it looks like one of the Muppets or even more like Kenny in South Park. :)

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

Re: M97: The Owl Nebula (APOD 2009 May 15)

Post by neufer » Sat May 16, 2009 1:59 pm

brett_w7 wrote:Maybe a hominid civilization manipulating their planetary nebula to point at the Sun in the shape of a hominid???
The shape of a hominid?? :shock: Rush Limbaugh?
Art Neuendorffer

Post Reply