A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Others » Astro Pictures
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

ASTRO: Holmberg VIII distant satellite of NGC 5033



 
 
Thread Tools Display Modes
  #1  
Old January 30th 13, 09:24 AM posted to alt.binaries.pictures.astro
Rick Johnson[_2_]
external usenet poster
 
Posts: 3,085
Default ASTRO: Holmberg VIII distant satellite of NGC 5033

Holmberg VIII/UGC 8303 is a companion to the far more famous NGC 5033 to
the north out of my field of view. It is located in Canes Venatici.
Distance measurements for it range from 54 million light-years by
redshift to 66 by a Tully-Fisher measurement. But as it is considered a
satellite galaxy of NGC 5033 the distance to that galaxy must be
considered. That covers an even wider range with APOD and a couple
other sources settling on 38 to 40 million light-years. NGC 5033 is
considered to have two satellites much like we have the two Magellanic
Clouds. They are Holmberg VIII and UGC 08314 also in my image to the
upper left of Holmberg VIII. NGC 5033 is also considered to have been
affected by NGC 5005 which I've not yet imaged. Which, if any caused
the strong warp seen in NGC 5033 I wasn't able to determine.

Holmberg VIII is classed by NED as IAB(s)m while UGC 08314 is listed as
Im:. UGC 08314 has a redshift distance of 54 million light-years, same
as Holmberg VIII. Since it is closely tied to NGC 5033 out of the image
which many sources say is 40 million light-years away that is more
likely the correct value. It has an odd vertical structure in the
middle and then a large very faint western half. The eastern side has
more bright areas and a small dim one to the northeast. A very
unsymmetrical galaxy indeed.

A bright blue blob inside of Holmberg is identified by NED as SDSS
J131318.46+361210.6. While listed as a separate galaxy it looks to me
to be just a star cloud in Holmberg VIII. I've listed it in the
annotated image. It does show a very slightly smaller redshift but I
don't see that as sufficient to call it a separate galaxy.

It seems every field I image has some discrepancy when I dig into my
research. This one is especially surprising. To the west of Holmberg
VIII is the galaxy group SHK 248 with 9 members at a distance of 3.15
billion light-years. The problem is a possible member on the western
side. NED shows two designations for it. SDSS J131210.13+361112.1 is
at the right position showing a distance of 2.32 billion light-years.
Too close to be a member. It's magnitude is in close agreement to my
measurement, 18.6. NED also lists 4" of arc to the northwest at a
position where nothing is seen, even on the Sloan survey image, 2MASX
J13121012+3611117 a galaxy at magnitude 19.4 at a redshift distance of
3.15 billion light-years, correct for the group. It's position is
listed with an error circle of 1", insufficient to overlap the only
galaxy in the area. I tend to believe the Sloan data placing it too
close to be part of the group.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

I've included an image of NGC 5033 taken and posted nearly 3 years ago.
That is east at the top rather than my usual north at the top as
Holmberg VIII is displayed.

Rick
--
Prefix is correct. Domain is arvig dot net

Attached Thumbnails
Click image for larger version

Name:	UGC8303L4X10RGB2X10D2.JPG
Views:	388
Size:	281.7 KB
ID:	4460  Click image for larger version

Name:	UGC8303L4X10RGB2X10D2ID.JPG
Views:	275
Size:	136.9 KB
ID:	4461  Click image for larger version

Name:	NGC5033L4X10RGB2X10-R2r.jpg
Views:	264
Size:	243.4 KB
ID:	4462  
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
ASTRO: NGC 5033 Stefan Lilge Astro Pictures 3 May 5th 11 09:17 PM
ASTRO: ARP 268/Holmberg II Interesting nearby irregular galaxy Rick Johnson[_2_] Astro Pictures 4 July 8th 09 08:17 PM
ASTRO: Reprocess of M81 eating Holmberg IX Rick Johnson[_2_] Astro Pictures 5 July 17th 07 01:13 AM
Astro: NGC 5033 another one Rick Johnson[_2_] Astro Pictures 9 June 6th 07 02:40 AM
ASTRO: NGC 5033 Stefan Lilge Astro Pictures 5 May 5th 07 10:36 PM


All times are GMT +1. The time now is 09:48 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.