OPEN STAR CLUSTERS
M-11 (NGC-6705): An exceptional galactic open cluster, located in the constellation
of Scutum. This rich cluster contains 400 stars brighter than 14th magnitude. Its visual
size is approximately 12 minutes of arc, which at its accepted distance of 5500 light
years translates to a diameter of approximately 20 light years.
NOTE: This image was captured on 8/17/2012 and is an integration of fifteen 50 second
exposures through the 11-inch Celestron at f/2 using HyperStar and the SXVR-H6.4C
color CCD imager. Captured and combined using Maxim DL 5 Pro. Post-processed using
Photoshop CS, levels, curves, Astro-tools and Gradient X-terminator. Noise filtered and
converted to JPEG format using NoiseWare.
of Scutum. This rich cluster contains 400 stars brighter than 14th magnitude. Its visual
size is approximately 12 minutes of arc, which at its accepted distance of 5500 light
years translates to a diameter of approximately 20 light years.
NOTE: This image was captured on 8/17/2012 and is an integration of fifteen 50 second
exposures through the 11-inch Celestron at f/2 using HyperStar and the SXVR-H6.4C
color CCD imager. Captured and combined using Maxim DL 5 Pro. Post-processed using
Photoshop CS, levels, curves, Astro-tools and Gradient X-terminator. Noise filtered and
converted to JPEG format using NoiseWare.
(CLICK ON THUMBNAIL IMAGE FOR FULL-SIZE VIEW)
M-71 (NGC-6838): Located in the constellation Sagitta, approximately midway between the stars Delta
and Gamma Sagittae. It lies approximately 12,000 light years from Earth and is about 27 light years
across. It was long thought to be an extremely dense open cluster because it lacked the dense central
compression found in globulars and lacked the RR Lyrae type variable stars usually found in globulars.
However, modern photometric research has detected a short "horizontal branch" in the H-R diagram of
stars in M-71, lending credibility to the fact that it MIGHT, in fact, be a loose globular cluster.
NOTE: This image was captured on 8/24/06, and is an integration of fifteen 40 second exposures
through the 80mm f/7.5 ED Apochromatic Refractor. Captured and combined using Maxim DL Essentials.
Post-processed using Photoshop CS, Carboni's Astro-tools, and NoiseWare.
and Gamma Sagittae. It lies approximately 12,000 light years from Earth and is about 27 light years
across. It was long thought to be an extremely dense open cluster because it lacked the dense central
compression found in globulars and lacked the RR Lyrae type variable stars usually found in globulars.
However, modern photometric research has detected a short "horizontal branch" in the H-R diagram of
stars in M-71, lending credibility to the fact that it MIGHT, in fact, be a loose globular cluster.
NOTE: This image was captured on 8/24/06, and is an integration of fifteen 40 second exposures
through the 80mm f/7.5 ED Apochromatic Refractor. Captured and combined using Maxim DL Essentials.
Post-processed using Photoshop CS, Carboni's Astro-tools, and NoiseWare.
NGC-7789: Located in the constellation of Cassiopeia, between the stars Rho and Sigma
Cassiopeiae. A very rich galactic open star cluster. It contains almost 1,000 stars, and its
visual size is approximately 20 minutes of arc, which translates to an actual diameter of
about 50 light years, given its accepted distance of 6,000 light years. Spectroscopic
study reveals this cluster to be much older than most open clusters.
NOTE: This image was captured on 9/1/06, and is an integration of ten 90 second
exposures through the 80mm f/7.5 ED Apochromatic Refractor. The images were
combined and processed in Maxim DL Essentials, with additional post-processing in
Photoshop CS.
Cassiopeiae. A very rich galactic open star cluster. It contains almost 1,000 stars, and its
visual size is approximately 20 minutes of arc, which translates to an actual diameter of
about 50 light years, given its accepted distance of 6,000 light years. Spectroscopic
study reveals this cluster to be much older than most open clusters.
NOTE: This image was captured on 9/1/06, and is an integration of ten 90 second
exposures through the 80mm f/7.5 ED Apochromatic Refractor. The images were
combined and processed in Maxim DL Essentials, with additional post-processing in
Photoshop CS.
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M-46 (NGC-2437): Located in the constellation of Puppis, about 14 degrees east of the
brilliant star Sirius (Alpha Canis Majoris). Discovered by Charles Messier in 1771. It con-
tains about 200 stars ranging from 10th magnitude down to 14th magnitude and has a
visual size of approximately 25 minutes of arc. The brightest members are blue giants of
spectral class AO, each having a true luminosity of over 100 times that of the sun. This
cluster lies at a distance of about 5400 light years from earth. A curious feature of this cluster is the
presence of the small planetary nebula NGC-2438, located approximately 7 arcminutes north of the
center of the cluster. It shows up in this CCD image just to the upper right of the center of the cluster. It
is believed that the nebula is not actually a member of M-46, as its radial velocity indicates that it is
probably 3300 light years from earth. This means that it is an "optical" or "line of sight" member of the
cluster.
NOTE: This image was captured on 3/14/2013 and is an integration of six 240-second exposures
through the C-11 at f/2 using HyperStar and the SXVR-H694C camera. Captured and combined using
Maxim DL 5. Post processed in Photoshop, levels, curves, gradient X-terminator and NoiseWare.
brilliant star Sirius (Alpha Canis Majoris). Discovered by Charles Messier in 1771. It con-
tains about 200 stars ranging from 10th magnitude down to 14th magnitude and has a
visual size of approximately 25 minutes of arc. The brightest members are blue giants of
spectral class AO, each having a true luminosity of over 100 times that of the sun. This
cluster lies at a distance of about 5400 light years from earth. A curious feature of this cluster is the
presence of the small planetary nebula NGC-2438, located approximately 7 arcminutes north of the
center of the cluster. It shows up in this CCD image just to the upper right of the center of the cluster. It
is believed that the nebula is not actually a member of M-46, as its radial velocity indicates that it is
probably 3300 light years from earth. This means that it is an "optical" or "line of sight" member of the
cluster.
NOTE: This image was captured on 3/14/2013 and is an integration of six 240-second exposures
through the C-11 at f/2 using HyperStar and the SXVR-H694C camera. Captured and combined using
Maxim DL 5. Post processed in Photoshop, levels, curves, gradient X-terminator and NoiseWare.
M-36 (NGC-1960): Located in the constellation of Auriga. A bright open star cluster con-
taining about 60 stars ranging in magnitudes from 9 to 14. Most of the brighter members are all B-type
blue-white stars. This is one of the younger open clusters in the milky way. It lies at a distance of
approximately 4100 light years from earth. At this distance, the angular size of the cluster, 12 arcminutes,
translates to an actual diameter of about 14 light years.
NOTE: This image was captured on the evening of October 30, 2008, and is an integration of twenty-five
25 second exposures through an 80mm APO refractor at f/3.75. The image were captured and combined
usingMaxim DL Essentials, with additional post-processing using Photoshop CS and Astro-Tools. Noise
filtered and converted to JPEG format using NoiseWare.
taining about 60 stars ranging in magnitudes from 9 to 14. Most of the brighter members are all B-type
blue-white stars. This is one of the younger open clusters in the milky way. It lies at a distance of
approximately 4100 light years from earth. At this distance, the angular size of the cluster, 12 arcminutes,
translates to an actual diameter of about 14 light years.
NOTE: This image was captured on the evening of October 30, 2008, and is an integration of twenty-five
25 second exposures through an 80mm APO refractor at f/3.75. The image were captured and combined
usingMaxim DL Essentials, with additional post-processing using Photoshop CS and Astro-Tools. Noise
filtered and converted to JPEG format using NoiseWare.
M-37 (NGC-2099):_A superbly rich open cluster in Auriga, considered one of the finest of the three
Messier open clusters in that constellation. M-37 contains over 150 stars ranging in magnitude from 9 to
12.5. The stellar population of this cluster is very different from M-36, and suggests that the cluster is much
older. It also contains several red giants, which stand out like rubys in a field of white diamonds. M-37 lies
at a distance of 4700 light years and is approximately 25 light years in diameter.
NOTE: This image was captured on the evening of October 30, 2008, and is an integration of twenty-five
25 second exposuresthrough an 80mm APO refractor at f/3.75. The images were combined and processed
in Maxim DL Essentials, with additional post-processing in Photoshop CS and Noiseware.
Messier open clusters in that constellation. M-37 contains over 150 stars ranging in magnitude from 9 to
12.5. The stellar population of this cluster is very different from M-36, and suggests that the cluster is much
older. It also contains several red giants, which stand out like rubys in a field of white diamonds. M-37 lies
at a distance of 4700 light years and is approximately 25 light years in diameter.
NOTE: This image was captured on the evening of October 30, 2008, and is an integration of twenty-five
25 second exposuresthrough an 80mm APO refractor at f/3.75. The images were combined and processed
in Maxim DL Essentials, with additional post-processing in Photoshop CS and Noiseware.
M-38 (NGC- 1912) and NGC-1907 (to the right - west): M-38 is a large bright open cluster in Auriga,
located about 2.3 degrees NW of M-36. It is a scattered group of irregular form,oriented NW to SE. It is
approximately 20 arcminutes in diameter, which at its calculated distance of 4200 light years corresponds to
an actual diameter of about 25 light years. The smaller, more compact open cluster NGC-1907 lies just at the
west edge of the field of this image.
NOTE: This image captured on October 30, 2008. It is an integration of twenty-five 25 second exposures
through the 80mm APO refractor at f/3.75. Combined and processed inMaxim DL Essentials, with
post-processing using Photoshop CS and Noiseware.
located about 2.3 degrees NW of M-36. It is a scattered group of irregular form,oriented NW to SE. It is
approximately 20 arcminutes in diameter, which at its calculated distance of 4200 light years corresponds to
an actual diameter of about 25 light years. The smaller, more compact open cluster NGC-1907 lies just at the
west edge of the field of this image.
NOTE: This image captured on October 30, 2008. It is an integration of twenty-five 25 second exposures
through the 80mm APO refractor at f/3.75. Combined and processed inMaxim DL Essentials, with
post-processing using Photoshop CS and Noiseware.
M-35 (NGC-2168) and NGC-2158: M-35 is a beautiful open star cluster in the constellation of Gemini. First
cataloged by de Cheseaux in 1745 and cataloged by Messier in 1764 as the 35th object on his list. Visually,
M-35 is about 30 arcminutes in diameter when viewed through modest sized telescopes. It lies at a distance of
approximately 2200 light years from earth. It containsabout 120 stars ranging from B3 to G0 in the main
sequence. Most of the members are 8th to10th magnitude. About 1/2 degree SW (upper right in the image)
from M-35 is the very rich and distant cluster NGC-2158. This cluster is actually the same physical size as M-35,
but lies over 8 times further away than M-35. Modern measurements place its distance at over 18,000 light
years. Through 8 to 12 inch telescopes, NGC-2158 appears as a very rich compressed cluster,somewhat
triangular in shape, with a misty, granular texture.
NOTE: This image was captured on 3/14/2013 and is an integration of five 240 second exposures through the
C-11 at f/2 using HyperStar and the Starlight Express SXVR-H694C color imager. Captured and combined using
Maxim DL 5. Post processed in Photoshop CS, levels, curves, Astro-tools, Gradient X-terminator and NoiseWare.
cataloged by de Cheseaux in 1745 and cataloged by Messier in 1764 as the 35th object on his list. Visually,
M-35 is about 30 arcminutes in diameter when viewed through modest sized telescopes. It lies at a distance of
approximately 2200 light years from earth. It containsabout 120 stars ranging from B3 to G0 in the main
sequence. Most of the members are 8th to10th magnitude. About 1/2 degree SW (upper right in the image)
from M-35 is the very rich and distant cluster NGC-2158. This cluster is actually the same physical size as M-35,
but lies over 8 times further away than M-35. Modern measurements place its distance at over 18,000 light
years. Through 8 to 12 inch telescopes, NGC-2158 appears as a very rich compressed cluster,somewhat
triangular in shape, with a misty, granular texture.
NOTE: This image was captured on 3/14/2013 and is an integration of five 240 second exposures through the
C-11 at f/2 using HyperStar and the Starlight Express SXVR-H694C color imager. Captured and combined using
Maxim DL 5. Post processed in Photoshop CS, levels, curves, Astro-tools, Gradient X-terminator and NoiseWare.
M-52 (NGC-7654): The brightest open cluster in the constellation Cassiopiea, located on the western edge of the
constellation. M-52 is a large, rich, fairly compressed cluster, which contains almost 120 stars from 9th to 12th
magnitude. It lies approximately 3000 light years from earth and is about 15 light years in diameter. The two
brightest members of the cluster are yellow giants of spectral class F9 and shine at 7.8 and 8.2 magnitude.
NOTE: This image was captured on the evening of 11/5/2010, and is an integration of twenty-four 30-second
exposures through the 11-inch Celestron at f/2, using the HyperStar system. Captured in Maxim DL Essentials,
processed in Nebulosity v.2.2.8, post-processed in Photoshop CS, levels, curves & color balance. Noise filtered
using NoiseWare.
constellation. M-52 is a large, rich, fairly compressed cluster, which contains almost 120 stars from 9th to 12th
magnitude. It lies approximately 3000 light years from earth and is about 15 light years in diameter. The two
brightest members of the cluster are yellow giants of spectral class F9 and shine at 7.8 and 8.2 magnitude.
NOTE: This image was captured on the evening of 11/5/2010, and is an integration of twenty-four 30-second
exposures through the 11-inch Celestron at f/2, using the HyperStar system. Captured in Maxim DL Essentials,
processed in Nebulosity v.2.2.8, post-processed in Photoshop CS, levels, curves & color balance. Noise filtered
using NoiseWare.
M-21 (NGC-6531): An open star cluster located in western Sagittarius, just north of the Trifid
Nebula (M-20). It is a relatively young cluster, being less than 5 million years old. It consists of
57 stars, many of which are blue-white giants. It lies at a distance of approximatley 2500 to 4000
light years from Earth.
NOTE: This image captured on the evening of July 14, 2012 and is an integration of ten 90-second
exposures through the Celestron 11-inch at f/2, using the HyperStar 3 imaging system and the
Starlight Express SXVR-H694C 1-shot color CCD camera. Captured and combined using Maxim DL
5 Pro. Post-processed using Photoshop CS, levels, curves, star reduction and Gradient
Exterminator.
Nebula (M-20). It is a relatively young cluster, being less than 5 million years old. It consists of
57 stars, many of which are blue-white giants. It lies at a distance of approximatley 2500 to 4000
light years from Earth.
NOTE: This image captured on the evening of July 14, 2012 and is an integration of ten 90-second
exposures through the Celestron 11-inch at f/2, using the HyperStar 3 imaging system and the
Starlight Express SXVR-H694C 1-shot color CCD camera. Captured and combined using Maxim DL
5 Pro. Post-processed using Photoshop CS, levels, curves, star reduction and Gradient
Exterminator.
NGC-6791: A very rich open star cluster located in the constellation of Lyra, the Lyre. This
cluster is thought to be one of the very oldest open clusters in our galaxy. Based on the
heavy metal content of its member stars, which contain over twice the amount of iron as
our sun, NGC-6791 is estimated to be almost 8 billion years old. Because of this as well as
its density, it is one of the most studied open clusters in our galaxy.
NOTE: This image was captured on August 10th, 2012 and is an integration of fifteen 60
second exposures through the 11-inch Celestron at f/2 using the HyperStar 3 imaging
system and the Starlight Express SXVR-H694C 6 megapixel camera. Captured and
combined in Maxim DL 5 Pro. Post-processed using Photoshop, levels & curves, Astro
Tools, and NoiseWare.
cluster is thought to be one of the very oldest open clusters in our galaxy. Based on the
heavy metal content of its member stars, which contain over twice the amount of iron as
our sun, NGC-6791 is estimated to be almost 8 billion years old. Because of this as well as
its density, it is one of the most studied open clusters in our galaxy.
NOTE: This image was captured on August 10th, 2012 and is an integration of fifteen 60
second exposures through the 11-inch Celestron at f/2 using the HyperStar 3 imaging
system and the Starlight Express SXVR-H694C 6 megapixel camera. Captured and
combined in Maxim DL 5 Pro. Post-processed using Photoshop, levels & curves, Astro
Tools, and NoiseWare.
M-6 (NGC-6405): One of the brightest galactic star clusters, and one of the nicest to observe
using a small telescope. Located 5 degrees north of the "tail" of Scorpius the Scorpion. It is an
oblong cluster of approximately 50 stars ranging from 6th down to 10.5 magnitude. Due to its
shape it is sometimes called "The Butterfly Cluster". It lies approximately 1500 light years from
Earth:
NOTE: This image was captured on the evening of September 10, 2012 and is an integration
of fifteen 50-second exposures through the 11-inch Celestron at f/2 using HyperStar and the
SXVR-H649C color CCD imager. Captured and combined using Maxim DL 5 Pro. Post
processed using Photoshop CS, levels, curves, and Gradient X-terminator. Noise filtered and
converted to JPEG format using NoiseWare.
using a small telescope. Located 5 degrees north of the "tail" of Scorpius the Scorpion. It is an
oblong cluster of approximately 50 stars ranging from 6th down to 10.5 magnitude. Due to its
shape it is sometimes called "The Butterfly Cluster". It lies approximately 1500 light years from
Earth:
NOTE: This image was captured on the evening of September 10, 2012 and is an integration
of fifteen 50-second exposures through the 11-inch Celestron at f/2 using HyperStar and the
SXVR-H649C color CCD imager. Captured and combined using Maxim DL 5 Pro. Post
processed using Photoshop CS, levels, curves, and Gradient X-terminator. Noise filtered and
converted to JPEG format using NoiseWare.
