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: WLM A funny, very nearby galaxy, with a funny name



 
 
Thread Tools Display Modes
  #1  
Old April 3rd 14, 08:21 AM posted to alt.binaries.pictures.astro
Rick Johnson[_2_]
external usenet poster
 
Posts: 3,085
Default ASTRO: WLM A funny, very nearby galaxy, with a funny name

The Wolf-Lundmark-Melotte galaxy was discovered by Max Wolf as a nebula
in 1909. At that time galaxies weren't really recognized. It wasn't
until 1926 that Knut Lundmark and P.J. Melotte determined it was a
galaxy. It is now recognized as a distant member of the local group
being some 3.4 million light-years distant by some sources. NED, using
26 measurements mostly using Tip of the Red Giant Branch and Cepheid
variable methods gives a median value of 3.2 million light-years.
Others sources say 3.0 million light-years. All agree it is more
distant than M31 but like M31 it is moving in our direction and is thus
blue shifted. As a member of the local group it is quite isolated with
its nearest neighbor being over 1 million light-years away. That one is
the rather well known IC 1613. I do need to retake that one as my data
for it from 2007 is awful, especially the color data. The WLM galaxy is
located in southwestern Cetus just below my normal 15 degree south
limit. Fortunately, I had an exceptional night so was able to capture
it though not with the detail I'd get if it was up out of the gunk.

The WLM galaxy is classified as IB(s)m at NED. Assuming the 3.4 million
light-year distance it is some 10,500 light years long and 6,200
light-years wide using the extent seen in my raw FITS files. It's
actual size is likely larger as the faint halo is hidden by my low
transparency this low over the lake even on a good night.

While there are many other galaxies in my image only one 2MFGC 00035 in
the upper left quadrant has any redshift data. That puts this rather
flat, edge on galaxy some 460 million light-years distant. NED makes no
attempt to classify it or any other galaxy in the image.

If WLM was higher in the sky I think I'd have been able to resolve many
more stars than I did. I live too far north to do this one justice. The
galaxy goes by other designations such as DDO 221, PGC 143, UGCA 444 and
MCG -03-01-015 to name a few.

Adding to the losses is the fact I left the low level floor lights on in
the observatory. Why they were on I don't remember. I see a skewing of
my normal color levels toward red due to this. Also the luminance
channel has a somewhat higher background than normal but neither were a
significant issue. It being so low did far more harm. Still I wish I'd
not left those floor lights on. The other object taken that night, NGC
784 also has this issue. Other than adding a slight, easily handled
gradient, I don't think the lights hurt it.

I should note that's a star in our galaxy at about the center of the
galaxy, not its core.

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

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

Attached Thumbnails
Click image for larger version

Name:	WLM_L4X10RGB2X10.JPG
Views:	309
Size:	335.7 KB
ID:	5051  
  #2  
Old April 8th 14, 09:13 PM posted to alt.binaries.pictures.astro
Stefan Lilge
external usenet poster
 
Posts: 2,269
Default ASTRO: WLM A funny, very nearby galaxy, with a funny name

Mighty image Rick. Lots of stars and/or clusters are resolved.
I wondered how I could have missed such a good galaxy until I saw you
mentioning it's southern declination...

Stefan

"Rick Johnson" schrieb im Newsbeitrag
...

The Wolf-Lundmark-Melotte galaxy was discovered by Max Wolf as a nebula
in 1909. At that time galaxies weren't really recognized. It wasn't
until 1926 that Knut Lundmark and P.J. Melotte determined it was a
galaxy. It is now recognized as a distant member of the local group
being some 3.4 million light-years distant by some sources. NED, using
26 measurements mostly using Tip of the Red Giant Branch and Cepheid
variable methods gives a median value of 3.2 million light-years.
Others sources say 3.0 million light-years. All agree it is more
distant than M31 but like M31 it is moving in our direction and is thus
blue shifted. As a member of the local group it is quite isolated with
its nearest neighbor being over 1 million light-years away. That one is
the rather well known IC 1613. I do need to retake that one as my data
for it from 2007 is awful, especially the color data. The WLM galaxy is
located in southwestern Cetus just below my normal 15 degree south
limit. Fortunately, I had an exceptional night so was able to capture
it though not with the detail I'd get if it was up out of the gunk.

The WLM galaxy is classified as IB(s)m at NED. Assuming the 3.4 million
light-year distance it is some 10,500 light years long and 6,200
light-years wide using the extent seen in my raw FITS files. It's
actual size is likely larger as the faint halo is hidden by my low
transparency this low over the lake even on a good night.

While there are many other galaxies in my image only one 2MFGC 00035 in
the upper left quadrant has any redshift data. That puts this rather
flat, edge on galaxy some 460 million light-years distant. NED makes no
attempt to classify it or any other galaxy in the image.

If WLM was higher in the sky I think I'd have been able to resolve many
more stars than I did. I live too far north to do this one justice. The
galaxy goes by other designations such as DDO 221, PGC 143, UGCA 444 and
MCG -03-01-015 to name a few.

Adding to the losses is the fact I left the low level floor lights on in
the observatory. Why they were on I don't remember. I see a skewing of
my normal color levels toward red due to this. Also the luminance
channel has a somewhat higher background than normal but neither were a
significant issue. It being so low did far more harm. Still I wish I'd
not left those floor lights on. The other object taken that night, NGC
784 also has this issue. Other than adding a slight, easily handled
gradient, I don't think the lights hurt it.

I should note that's a star in our galaxy at about the center of the
galaxy, not its core.

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

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

  #3  
Old April 8th 14, 11:35 PM posted to alt.binaries.pictures.astro
Rick Johnson[_2_]
external usenet poster
 
Posts: 3,085
Default ASTRO: WLM A funny, very nearby galaxy, with a funny name

I had to wait many years to get needed transparency and somewhat usable
seeing that low. I had tried it the first year I had the observatory
running. The results were pretty bad. I'd not had a chance to try
again until last September.

Rick

On 4/8/2014 3:13 PM, Stefan Lilge wrote:
Mighty image Rick. Lots of stars and/or clusters are resolved.
I wondered how I could have missed such a good galaxy until I saw you
mentioning it's southern declination...

Stefan

"Rick Johnson" schrieb im Newsbeitrag
...

The Wolf-Lundmark-Melotte galaxy was discovered by Max Wolf as a nebula
in 1909. At that time galaxies weren't really recognized. It wasn't
until 1926 that Knut Lundmark and P.J. Melotte determined it was a
galaxy. It is now recognized as a distant member of the local group
being some 3.4 million light-years distant by some sources. NED, using
26 measurements mostly using Tip of the Red Giant Branch and Cepheid
variable methods gives a median value of 3.2 million light-years.
Others sources say 3.0 million light-years. All agree it is more
distant than M31 but like M31 it is moving in our direction and is thus
blue shifted. As a member of the local group it is quite isolated with
its nearest neighbor being over 1 million light-years away. That one is
the rather well known IC 1613. I do need to retake that one as my data
for it from 2007 is awful, especially the color data. The WLM galaxy is
located in southwestern Cetus just below my normal 15 degree south
limit. Fortunately, I had an exceptional night so was able to capture
it though not with the detail I'd get if it was up out of the gunk.

The WLM galaxy is classified as IB(s)m at NED. Assuming the 3.4 million
light-year distance it is some 10,500 light years long and 6,200
light-years wide using the extent seen in my raw FITS files. It's
actual size is likely larger as the faint halo is hidden by my low
transparency this low over the lake even on a good night.

While there are many other galaxies in my image only one 2MFGC 00035 in
the upper left quadrant has any redshift data. That puts this rather
flat, edge on galaxy some 460 million light-years distant. NED makes no
attempt to classify it or any other galaxy in the image.

If WLM was higher in the sky I think I'd have been able to resolve many
more stars than I did. I live too far north to do this one justice. The
galaxy goes by other designations such as DDO 221, PGC 143, UGCA 444 and
MCG -03-01-015 to name a few.

Adding to the losses is the fact I left the low level floor lights on in
the observatory. Why they were on I don't remember. I see a skewing of
my normal color levels toward red due to this. Also the luminance
channel has a somewhat higher background than normal but neither were a
significant issue. It being so low did far more harm. Still I wish I'd
not left those floor lights on. The other object taken that night, NGC
784 also has this issue. Other than adding a slight, easily handled
gradient, I don't think the lights hurt it.

I should note that's a star in our galaxy at about the center of the
galaxy, not its core.

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

Rick



--
Prefix is correct. Domain is arvig dot net
 




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: Abell 194 A nearby galaxy cluster Rick Johnson[_2_] Astro Pictures 0 June 25th 13 07:05 AM
ASTRO: NGC 2146 A highly disturbed nearby galaxy. Rick Johnson[_2_] Astro Pictures 0 September 27th 12 07:55 AM
ASTRO: NGC 1156 A nearby blue dwarf galaxy Rick Johnson[_2_] Astro Pictures 2 March 22nd 12 11:11 PM
ASTRO: ARP 268/Holmberg II Interesting nearby irregular galaxy Rick Johnson[_2_] Astro Pictures 4 July 8th 09 08:17 PM
Funny story about astro [email protected] Astronomy Misc 2 December 19th 04 10:12 PM


All times are GMT +1. The time now is 11:20 PM.


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.