ASTRO: Arp 28

Arp 28 sits in a rather empty part of the sky. It is in Arp's class:
Spiral Galaxies: One heavy arm. In some cases I've had trouble seeing
which arm Arp was talking about but this one is quite obvious for a
change. Arp 28 is also known as NGC 7678 and is located near the center
of the Great Square of Pegasus. It is classed as SAB(rs)c and is both a
Seyfert 2 and starburst galaxy. It appears that heavy arm as a lot to
do with the starburst classification. Arp's note: "Note straight heavy
arm." The heavy arm is somewhat straight but so are other arm segments
of the galaxy. It certainly is a disturbed galaxy. Red shift puts it
about 140 million light years away. A single Sosies measurement shows a
slightly closer distance of 115 million light years. I'm not sure such
a measurement is all that accurate for a highly disturbed galaxy but
then neither is redshift if the galaxy has had a close encounter than
has accelerated it.

So has it encountered another galaxy? There's none in my image but
that's my error. UGC 12619 is just below the bottom edge of my image.
Somehow I didn't see it was there so put Arp 28 in the center of the
image rather than a few minutes above center which would have then shown
this galaxy. Red shift puts it at about 160 million light years. A bit
further than Arp 28. Is it the culprit? It is a dim, low surface
brightness galaxy with very disturbed spiral structure. It's classed as
SAB(s)dm.

The area of Arp 28 is outside the SDSS search area nor has Hubble imaged
it. NED has little detail on any of the other galaxies in the image.
You have to look hard to find many. The largest and brightest, a blue
galaxy to the northwest of Arp 28 isn't in NED. Only IR galaxies from
the 2MASX survey are listed. Those tend to look red though that isn't
necessarily the case.

Arp's image:
http://nedwww.ipac.caltech.edu/level...big_arp28.jpeg

14" LX200R @ f/10, L=4x10 RGB=2x10x3, 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".

Oops, change "million" to billion. I must have had the anti Carl Sagan
disease when I wrote this.
Rick

On 5/2/2010 12:51 AM, Rick Johnson wrote:
Arp 28 sits in a rather empty part of the sky. It is in Arp's class:
Spiral Galaxies: One heavy arm. In some cases I've had trouble seeing
which arm Arp was talking about but this one is quite obvious for a
change. Arp 28 is also known as NGC 7678 and is located near the center
of the Great Square of Pegasus. It is classed as SAB(rs)c and is both a
Seyfert 2 and starburst galaxy. It appears that heavy arm as a lot to do
with the starburst classification. Arp's note: "Note straight heavy
arm." The heavy arm is somewhat straight but so are other arm segments
of the galaxy. It certainly is a disturbed galaxy. Red shift puts it
about 140 million light years away. A single Sosies measurement shows a
slightly closer distance of 115 million light years. I'm not sure such a
measurement is all that accurate for a highly disturbed galaxy but then
neither is redshift if the galaxy has had a close encounter than has
accelerated it.

So has it encountered another galaxy? There's none in my image but
that's my error. UGC 12619 is just below the bottom edge of my image.
Somehow I didn't see it was there so put Arp 28 in the center of the
image rather than a few minutes above center which would have then shown
this galaxy. Red shift puts it at about 160 million light years. A bit
further than Arp 28. Is it the culprit? It is a dim, low surface
brightness galaxy with very disturbed spiral structure. It's classed as
SAB(s)dm.

The area of Arp 28 is outside the SDSS search area nor has Hubble imaged
it. NED has little detail on any of the other galaxies in the image. You
have to look hard to find many. The largest and brightest, a blue galaxy
to the northwest of Arp 28 isn't in NED. Only IR galaxies from the 2MASX
survey are listed. Those tend to look red though that isn't necessarily
the case.

Arp's image:
http://nedwww.ipac.caltech.edu/level...big_arp28.jpeg

14" LX200R @ f/10, L=4x10 RGB=2x10x3, 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".

Rats I was right the first time. Someone emailed me that I was wrong
and stupidly I agreed. No I wasn't. I need more sleep.
Rick

On 5/3/2010 11:53 PM, Rick Johnson wrote:
Oops, change "million" to billion. I must have had the anti Carl Sagan
disease when I wrote this.
Rick

On 5/2/2010 12:51 AM, Rick Johnson wrote:
Arp 28 sits in a rather empty part of the sky. It is in Arp's class:
Spiral Galaxies: One heavy arm. In some cases I've had trouble seeing
which arm Arp was talking about but this one is quite obvious for a
change. Arp 28 is also known as NGC 7678 and is located near the center
of the Great Square of Pegasus. It is classed as SAB(rs)c and is both a
Seyfert 2 and starburst galaxy. It appears that heavy arm as a lot to do
with the starburst classification. Arp's note: "Note straight heavy
arm." The heavy arm is somewhat straight but so are other arm segments
of the galaxy. It certainly is a disturbed galaxy. Red shift puts it
about 140 million light years away. A single Sosies measurement shows a
slightly closer distance of 115 million light years. I'm not sure such a
measurement is all that accurate for a highly disturbed galaxy but then
neither is redshift if the galaxy has had a close encounter than has
accelerated it.

So has it encountered another galaxy? There's none in my image but
that's my error. UGC 12619 is just below the bottom edge of my image.
Somehow I didn't see it was there so put Arp 28 in the center of the
image rather than a few minutes above center which would have then shown
this galaxy. Red shift puts it at about 160 million light years. A bit
further than Arp 28. Is it the culprit? It is a dim, low surface
brightness galaxy with very disturbed spiral structure. It's classed as
SAB(s)dm.

The area of Arp 28 is outside the SDSS search area nor has Hubble imaged
it. NED has little detail on any of the other galaxies in the image. You
have to look hard to find many. The largest and brightest, a blue galaxy
to the northwest of Arp 28 isn't in NED. Only IR galaxies from the 2MASX
survey are listed. Those tend to look red though that isn't necessarily
the case.

Arp's image:
http://nedwww.ipac.caltech.edu/level...big_arp28.jpeg

14" LX200R @ f/10, L=4x10 RGB=2x10x3, 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".

Are you sure, Rick? 140 million LY should read 140 billion LY? isn't your
universe a bit too big? grin

-----
Clear skies,
Beta Persei


"Rick Johnson" ha scritto nel messaggio
. com...
Oops, change "million" to billion. I must have had the anti Carl Sagan
disease when I wrote this.
Rick

...Red shift puts it
about 140 million light years away. A single Sosies measurement shows a
slightly closer distance of 115 million light years... ... Red shift puts
it at about 160 million light years...


The area of Arp 28 is outside the SDSS search area nor has Hubble imaged
it. NED has little detail on any of the other galaxies in the image. You
have to look hard to find many. The largest and brightest, a blue galaxy
to the northwest of Arp 28 isn't in NED. Only IR galaxies from the 2MASX
survey are listed. Those tend to look red though that isn't necessarily
the case.

Arp's image:
http://nedwww.ipac.caltech.edu/level...big_arp28.jpeg

14" LX200R @ f/10, L=4x10 RGB=2x10x3, 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".

well, I need sleep too...didn't notice you've already corrected the
statement... grin

Clear skies,
Beta Persei

"Beta Persei" b ha scritto nel messaggio
. ..
Are you sure, Rick? 140 million LY should read 140 billion LY? isn't your
universe a bit too big? grin

-----
Clear skies,
Beta Persei


"Rick Johnson" ha scritto nel messaggio
. com...
Oops, change "million" to billion. I must have had the anti Carl Sagan
disease when I wrote this.
Rick

...Red shift puts it
about 140 million light years away. A single Sosies measurement shows a
slightly closer distance of 115 million light years... ... Red shift
puts it at about 160 million light years...


The area of Arp 28 is outside the SDSS search area nor has Hubble imaged
it. NED has little detail on any of the other galaxies in the image. You
have to look hard to find many. The largest and brightest, a blue galaxy
to the northwest of Arp 28 isn't in NED. Only IR galaxies from the 2MASX
survey are listed. Those tend to look red though that isn't necessarily
the case.

Arp's image:
http://nedwww.ipac.caltech.edu/level...big_arp28.jpeg

14" LX200R @ f/10, L=4x10 RGB=2x10x3, 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".