A Space & astronomy forum. SpaceBanter.com

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

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

ASTRO: Arp 284 Galaxies in collision



 
 
Thread Tools Display Modes
  #1  
Old September 15th 08, 08:13 PM posted to alt.binaries.pictures.astro
Rick Johnson[_2_]
external usenet poster
 
Posts: 3,085
Default ASTRO: Arp 284 Galaxies in collision

Arp 284 is a pair of interacting galaxies NGC 7715 and NGC 7714 left to
right. Arp classifies these under the heading of "infall and
attraction" whatever that means. They are located a bit over 100
million light years away in the constellation of Pisces. NGC 7714 is a
starburst galaxy. It has strong H alpha emission though I didn't take
it in that light so its not well seen in my shot. The starburst
occurred some 3 to 9 million years ago. Note the odd reddish tidal arm
at the lower right that just doesn't seem to fit the rest of the galaxy.
The companion NGC 7715 has no significant H alpha emission and is not
a starburst galaxy. It is classed as an irregular galaxy and is not an
edge on spiral as it might appear. 7714 is a SB spiral that has been
highly distorted by the interaction. Its core has emission lines that
classify it as a LINER galaxy, a type with a somewhat active black hole
in its nucleus.

The bright star at the upper right of the image is also very
interesting. It is SAO 128268 and is 126 light years away. What is
interesting is that it is moving very rapidly through the sky. I was
checking the POSS1 plates when I noticed it wasn't in the same place as
it is in my photo.
http://stdatu.stsci.edu/cgi-bin/dss_...fov=NONE&v3 =
Note the two stars on either side of it are above it in that photo yet
below it in my shot. It is moving upward and a bit to the east at a
rate of about 1/3rd of a second of arc per year. In the approximately
50 years between the photos, the motion is quite obvious.

The star just below Arp 284 is one of the very few in all my images that
is visible to the naked eye. 16 Psc shines at magnitude 5.7 It is a
spectroscopic double star about 100 light years away known as HD 221950
or 16 Psc. It's glare made processing this image very difficult.
Reading through some of the scientific papers on this pair many mention
their measurements have large error bars due to the star so they were
bothered by it as well.

A Kitt Peak photo of Arp 284 is at:
http://www.noao.edu/outreach/aop/observers/n7714.html
It is a mirror image for some reason. Also the star cloud in 7714 that
is very blue in my image is quite red in the Kitt Peak shot. The
difference is likely due to our handling of the blue glare of 16 Psc.
Since such star clouds are normally blue I'll go out on a very thin limb
and vote for mine being more correct Probably foolhardy as that is an
Adam Brock image.

One other object to find in this image is a very blue "star" that is to
the upper left of NGC 7715. It is about halfway between two orange
stars. As the quotes indicate this isn't a star at all. While NGC 7714
is a LINER galaxy, that is, one with a weakly active black hole at its
center the other end of this spectrum is the quasar. They are a black
hole at the center of a galaxy that's so active it gives off more light
than an entire galaxy of a trillion stars! That's what this blue
star-like object really is. It is the active black hole of a galaxy
over 9.8 BILLION light years, light travel time, away.

14" LX200R @ f/10, L=4x10' binned 2x2 RGB=2x10' binned 3x3, STL-11000XM,
Paramount ME

Rick
--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

Attached Thumbnails
Click image for larger version

Name:	NGC7714-5ARP284L4X10RGB2X10X3.jpg
Views:	281
Size:	353.4 KB
ID:	2183  
Ads
  #2  
Old September 16th 08, 10:24 PM posted to alt.binaries.pictures.astro
Stefan Lilge
external usenet poster
 
Posts: 2,269
Default ASTRO: Arp 284 Galaxies in collision

Great picture Rick. This is an interesting pair and some good information to
go with it.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
ster.com...
Arp 284 is a pair of interacting galaxies NGC 7715 and NGC 7714 left to
right. Arp classifies these under the heading of "infall and
attraction" whatever that means. They are located a bit over 100
million light years away in the constellation of Pisces. NGC 7714 is a
starburst galaxy. It has strong H alpha emission though I didn't take
it in that light so its not well seen in my shot. The starburst
occurred some 3 to 9 million years ago. Note the odd reddish tidal arm
at the lower right that just doesn't seem to fit the rest of the galaxy.
The companion NGC 7715 has no significant H alpha emission and is not
a starburst galaxy. It is classed as an irregular galaxy and is not an
edge on spiral as it might appear. 7714 is a SB spiral that has been
highly distorted by the interaction. Its core has emission lines that
classify it as a LINER galaxy, a type with a somewhat active black hole
in its nucleus.

The bright star at the upper right of the image is also very
interesting. It is SAO 128268 and is 126 light years away. What is
interesting is that it is moving very rapidly through the sky. I was
checking the POSS1 plates when I noticed it wasn't in the same place as
it is in my photo.
http://stdatu.stsci.edu/cgi-bin/dss_...fov=NONE&v3 =
Note the two stars on either side of it are above it in that photo yet
below it in my shot. It is moving upward and a bit to the east at a
rate of about 1/3rd of a second of arc per year. In the approximately
50 years between the photos, the motion is quite obvious.

The star just below Arp 284 is one of the very few in all my images that
is visible to the naked eye. 16 Psc shines at magnitude 5.7 It is a
spectroscopic double star about 100 light years away known as HD 221950
or 16 Psc. It's glare made processing this image very difficult.
Reading through some of the scientific papers on this pair many mention
their measurements have large error bars due to the star so they were
bothered by it as well.

A Kitt Peak photo of Arp 284 is at:
http://www.noao.edu/outreach/aop/observers/n7714.html
It is a mirror image for some reason. Also the star cloud in 7714 that
is very blue in my image is quite red in the Kitt Peak shot. The
difference is likely due to our handling of the blue glare of 16 Psc.
Since such star clouds are normally blue I'll go out on a very thin limb
and vote for mine being more correct Probably foolhardy as that is an
Adam Brock image.

One other object to find in this image is a very blue "star" that is to
the upper left of NGC 7715. It is about halfway between two orange
stars. As the quotes indicate this isn't a star at all. While NGC 7714
is a LINER galaxy, that is, one with a weakly active black hole at its
center the other end of this spectrum is the quasar. They are a black
hole at the center of a galaxy that's so active it gives off more light
than an entire galaxy of a trillion stars! That's what this blue
star-like object really is. It is the active black hole of a galaxy
over 9.8 BILLION light years, light travel time, away.

14" LX200R @ f/10, L=4x10' binned 2x2 RGB=2x10' binned 3x3, STL-11000XM,
Paramount ME

Rick
--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".



 




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: M106 and surrounding galaxies David Cash[_2_] Astro Pictures 4 May 30th 07 08:03 PM
ASTRO: Some Field Galaxies........ Preston S Justis Astro Pictures 3 April 26th 07 03:07 AM
ASTRO: M65 and M66 Galaxies Richard Crisp Amateur Astronomy 26 February 23rd 04 08:44 PM
ASTRO: M65 and M66 Galaxies Richard Crisp CCD Imaging 12 February 21st 04 04:35 AM
Collision of Galaxies scenarios Raj Diva Research 2 February 4th 04 12:27 AM


All times are GMT +1. The time now is 03:55 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Copyright 2004-2019 SpaceBanter.com.
The comments are property of their posters.