Astro: M10 Sometimes I take something everyone images

M10 is a rather large, in angular size, globular in Ophiuchus about
14,300 light-years from us and about 16,000 light years from the center
of the galaxy. Most globulars are rather well endowed with variable
stars. Not M-10, it has only 3. While Messier didn't discover many of
the entries to his catalog he did discover this one on May 29, 1764. He
described it as a "Nebula without stars, very pale." William Herschel
was the first to see its true nature as being composed of stars saying
"beautiful cluster of extremely compressed stars".

Most Messier globulars are so bright in the core I can't use my standard
10 minute luminance exposure without burning in the core. I was
surprised to find that while it appears rather bright to the eye I was
still able to use 10 minute luminance exposures. In fact I'd not
intended to use a luminance channel, just a bunch (6 each) of RGB
exposures. Unfortunately my horrid 2012 weather wiped most of those out
leaving me with too few. So after several nights of trying I did
finally grab 4 luminance frames. Likely part of the reason I could use
10 minute frames was the very poor transparency that night.

There are a couple asteroids in the image. The most obvious is on the
left a bit below centerline. It is (119503) 2001 UR124 at an estimated
magnitude of 18.2. Normally such a bright asteroid would really stand
out. It is rather dim here due to the poor transparency. The other one
is difficult to see. It is near the bottom a bit left of centerline.
The left end of the trail is lost in a rather dim star at the apex of 5
dim stars in the pattern of the ^ symbol. It is (69357) 1994 FU at an
estimated 19.1 magnitude. There's a third one in the southern part of
the cluster but at magnitude 19.7 it didn't survive the color image. I
can barely see it in the luminance FITS stack if I use averted
imagination. It is (154523) 2003 FF92.

There are several galaxies in the image but only 2 have redshift values.
With only two I didn't prepare an annotated image. One is lost among
the stars of the globular less than half way from the core to the edge
(6dF J1656595-040746). The other is near the left edge above center and
is just a typical small red fuzzy spot. NED lists both with EXACTLY the
same redshift. z=0.087107. I find this very unusual. I've never seen
this happen even in very dense galaxy clusters. Is one a misprint?
That value translates to a light-travel time distance of 1.14 billion
light-years using NED's 5 year WMAP calculation.

An HST image of the very center of the cluster in false color can be
seen at:
http://www.nasa.gov/mission_pages/hu...uster-m10.html . The
galaxy in the lower right corner of the HST image is not the one in NED.
It is much closer to the core. The HST image has north to the left
while mine has north at the top.

I posted a full size image and a smaller one at 1.5" per pixel as the
added resolution of the 1" per pixel image added little but some who
print these out want the full size image so I've included both.

14" LX200R @ f/10, L=4x10' RG=2x10' B=3x10', STL-11000XM, Paramount ME

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

On Thu, 28 Mar 2013 00:34:40 -0700, Rick Johnson wrote:

M10 is a rather large, in angular size, globular in Ophiuchus about
14,300 light-years from us and about 16,000 light years from the center
of the galaxy. Most globulars are rather well endowed with variable
stars. Not M-10, it has only 3. While Messier didn't discover many of
the entries to his catalog he did discover this one on May 29, 1764. He
described it as a "Nebula without stars, very pale." William Herschel
was the first to see its true nature as being composed of stars saying
"beautiful cluster of extremely compressed stars".

Most Messier globulars are so bright in the core I can't use my standard
10 minute luminance exposure without burning in the core. I was
surprised to find that while it appears rather bright to the eye I was
still able to use 10 minute luminance exposures. In fact I'd not
intended to use a luminance channel, just a bunch (6 each) of RGB
exposures. Unfortunately my horrid 2012 weather wiped most of those out
leaving me with too few. So after several nights of trying I did
finally grab 4 luminance frames. Likely part of the reason I could use
10 minute frames was the very poor transparency that night.

There are a couple asteroids in the image. The most obvious is on the
left a bit below centerline. It is (119503) 2001 UR124 at an estimated
magnitude of 18.2. Normally such a bright asteroid would really stand
out. It is rather dim here due to the poor transparency. The other one
is difficult to see. It is near the bottom a bit left of centerline.
The left end of the trail is lost in a rather dim star at the apex of 5
dim stars in the pattern of the ^ symbol. It is (69357) 1994 FU at an
estimated 19.1 magnitude. There's a third one in the southern part of
the cluster but at magnitude 19.7 it didn't survive the color image. I
can barely see it in the luminance FITS stack if I use averted
imagination. It is (154523) 2003 FF92.

There are several galaxies in the image but only 2 have redshift values.
With only two I didn't prepare an annotated image. One is lost among
the stars of the globular less than half way from the core to the edge
(6dF J1656595-040746). The other is near the left edge above center and
is just a typical small red fuzzy spot. NED lists both with EXACTLY the
same redshift. z=0.087107. I find this very unusual. I've never seen
this happen even in very dense galaxy clusters. Is one a misprint?
That value translates to a light-travel time distance of 1.14 billion
light-years using NED's 5 year WMAP calculation.

An HST image of the very center of the cluster in false color can be
seen at:
http://www.nasa.gov/mission_pages/hu...uster-m10.html . The
galaxy in the lower right corner of the HST image is not the one in NED.
It is much closer to the core. The HST image has north to the left
while mine has north at the top.

I posted a full size image and a smaller one at 1.5" per pixel as the
added resolution of the 1" per pixel image added little but some who
print these out want the full size image so I've included both.

14" LX200R @ f/10, L=4x10' RG=2x10' B=3x10', STL-11000XM, Paramount ME

Rick


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Using Opera's mail client: http://www.opera.com/mail/

On Thu, 28 Mar 2013 00:34:40 -0700, Rick Johnson wrote:

M10 is a rather large, in angular size, globular in Ophiuchus about
14,300 light-years from us and about 16,000 light years from the center
of the galaxy. Most globulars are rather well endowed with variable
stars. Not M-10, it has only 3. While Messier didn't discover many of
the entries to his catalog he did discover this one on May 29, 1764. He
described it as a "Nebula without stars, very pale." William Herschel
was the first to see its true nature as being composed of stars saying
"beautiful cluster of extremely compressed stars".

Most Messier globulars are so bright in the core I can't use my standard
10 minute luminance exposure without burning in the core. I was
surprised to find that while it appears rather bright to the eye I was
still able to use 10 minute luminance exposures. In fact I'd not
intended to use a luminance channel, just a bunch (6 each) of RGB
exposures. Unfortunately my horrid 2012 weather wiped most of those out
leaving me with too few. So after several nights of trying I did
finally grab 4 luminance frames. Likely part of the reason I could use
10 minute frames was the very poor transparency that night.

There are a couple asteroids in the image. The most obvious is on the
left a bit below centerline. It is (119503) 2001 UR124 at an estimated
magnitude of 18.2. Normally such a bright asteroid would really stand
out. It is rather dim here due to the poor transparency. The other one
is difficult to see. It is near the bottom a bit left of centerline.
The left end of the trail is lost in a rather dim star at the apex of 5
dim stars in the pattern of the ^ symbol. It is (69357) 1994 FU at an
estimated 19.1 magnitude. There's a third one in the southern part of
the cluster but at magnitude 19.7 it didn't survive the color image. I
can barely see it in the luminance FITS stack if I use averted
imagination. It is (154523) 2003 FF92.

There are several galaxies in the image but only 2 have redshift values.
With only two I didn't prepare an annotated image. One is lost among
the stars of the globular less than half way from the core to the edge
(6dF J1656595-040746). The other is near the left edge above center and
is just a typical small red fuzzy spot. NED lists both with EXACTLY the
same redshift. z=0.087107. I find this very unusual. I've never seen
this happen even in very dense galaxy clusters. Is one a misprint?
That value translates to a light-travel time distance of 1.14 billion
light-years using NED's 5 year WMAP calculation.

An HST image of the very center of the cluster in false color can be
seen at:
http://www.nasa.gov/mission_pages/hu...uster-m10.html . The
galaxy in the lower right corner of the HST image is not the one in NED.
It is much closer to the core. The HST image has north to the left
while mine has north at the top.

I posted a full size image and a smaller one at 1.5" per pixel as the
added resolution of the 1" per pixel image added little but some who
print these out want the full size image so I've included both.

14" LX200R @ f/10, L=4x10' RG=2x10' B=3x10', STL-11000XM, Paramount ME

Rick


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"Rick Johnson" wrote in message
...


I wish you would post more of what "everyone else" images.
jim