Sculptor dwarf galaxy

[glenc]

Saw the Sculptor dwarf galaxy last night with my 12" Dob and a 30mm EP (50X, 90' field).
The core, diameter 10', was visible when I moved my scope back and forth.
Here is an image by Scott (tornado33): http://www.iceinspace.com.au/forum/attachment.php?attachmentid=49477&d=1225108752
Paddy (Patrick) saw this a few days ago.
Here is some more info: http://seds.org/~spider/spider/LG/scl_dw.html

[Gargoyle_Steve]

That's a serious bit of observing Glen, congratulations! I'm stunned at how faint it appears even in Scott's image.
:thumbsup:

[hector]

Well done Glen. great observation.
Scott that image is fantastic it really shows the low surface brightness of the galaxy. What camera and lens set up was iuse to take the photo? Do you know the scale of the image? It looks to me about 20 degrees across at least.
Andrew

[glenc]

The B mag is 10.3 and B-V is 0.85, the SB is 26.9 mag/sq arc sec.
Size is 65' x 55' but I only saw 10', distance is 500,000 light yrs. (40' x 30' and 290,000 l.yrs in Wikipedia)

As a comparison the Fornax Dwarf has B mag = 9.1 and B-V = 0.84, the SB is also 26.9 mag/sq arc sec.
Size = 70' x 60', distance = 300,000 light yrs. (17' x 13' and 460,000 l yrs in Wikipedia)

[Paddy]

Interesting that you found it helpful to move the scope to see the core. This is what I found myself doing. I'm not sure how that helped, but it sure did. It also helped me convince myself that I was actually seeing something, not just imagining it.

Thanks for the links.

[glenc]

I think the Sculptor Dwarf is closer than the Fornax Dwarf and easier to see.
DSS images support this, but the distances below (in #4) are contradictory.
This page gives the distances as Scl 300kly and For 500kly: http://www.seds.org/Messier/more/local.html
Here are some more distances, Scl 258kly and For 450kly: http://www.atlasoftheuniverse.com/galaxies.html

[glenc]

SagDEG was until recently thought to be the nearest galaxy. [diameter 8x3 deg]
"Globular cluster M54 (http://www.seds.org/messier/m/m054.html) coincides with one of the [SagDEG] galaxy's two bright knots, and is also receding at about the same velocity. It may also be at the same distance (about 88,000 light years), so probably M54 is the first "extragalactic" globular ever discovered ...

Because of the extreme intrinsic luminosity of M54 in comparison to the other globular clusters associated with SagDEG, it has been speculated early that M54 may be the nucleus of this dwarf galaxy, or the remnant of its nucleus (Bassino and Muzzio, 1995 (http://www.seds.org/messier/more/SagdEg.html#bassino1995))..."
http://www.seds.org/messier/more/SagdEg.html
http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995Obs...115..2 56B&link_type=ARTICLE&db_key=AST&high=

[glenc]

"The Canis Major dwarf galaxy (http://en.wikipedia.org/wiki/Dwarf_galaxy) [diameter 12 degrees] is classified as an irregular galaxy (http://en.wikipedia.org/wiki/Irregular_galaxy) and is now thought to be the closest neighbouring galaxy to our location in the Milky Way (http://en.wikipedia.org/wiki/Milky_Way), being located about 25,000 light-years away from our Solar System (http://en.wikipedia.org/wiki/Solar_System)..

Globular clusters thought to be associated with the Canis Major Dwarf galaxy include NGC 1851 (http://en.wikipedia.org/wiki/NGC_1851), NGC 1904 (M79) (http://en.wikipedia.org/wiki/NGC_1904), NGC 2298 (http://en.wikipedia.org/w/index.php?title=NGC_2298&action=edit&redlink=1) and NGC 2808 (http://en.wikipedia.org/wiki/NGC_2808), all of which are likely to be a remnant of the galaxy's globular cluster system before its accretion (http://en.wikipedia.org/wiki/Accretion_%28astrophysics%29), or swallowing, into the Milky Way..."

http://en.wikipedia.org/wiki/Canis_Major_Dwarf_Galaxy

[glenc]

I compared the Fornax and Sculptor Dwarf galaxies last night. I think Scl is slightly brighter in a 12" at low power.