Descriptive information was drawn from The Sky Atlas 2000.0, 2nd Edition by R. A. Strong and R. W. Sinnott with descriptions by W. Tirion and R. W. Sinnott (2000, Sky Publishing Corp. and Cambridge University Press), and Burnham's Celestial Handbook by Robert Burnham, Jr. (1978, Dover Publications, Inc.). North is up and east to the left in all photos. Every effort has been made to display all photos at the same magnification unless otherwise stated.

M3 13h 42.2m +28° 23´ Canes Venatici 6.4 Sky Atlas 2000.0
chart 7
M3 2009-05-09
NGC 5272

2009-05-09
White balance = 6000K (Cloudy)
Noise reduction = Off
Prime focus (32.5×)
Created from my forty-six best 20 s, ISO 1600 photos. I removed a darkframe and flatfield, enhanced the contrast for each. I averaged the modified photos in five groups of eight plus one group of six and enhanced the contrast again. I averaged the combinations and enhanced the contrast. Finally, I rotated to north-up, cropped and scaled the image to 33.3%.

Big, bright and attractive, M3 is, justifiably, popular with amateurs. M3 is about 48,000 l.y. distant and 16´ across implying it is 220 l.y. in diameter.

M3 is popular with me too as is evidenced by the photos below in 2005, 2006 and 2009, from left to right respectively. These photos are fun because they show how my photography has evolved: the changes between the first and second demonstrate an improvement in my skill; between the second and third demonstrate an improvement in my equipment.
m3 2005-04-15
Created by combining four 20 s, f/2.9, ISO 400 photos, 25.0 mm eyepiece (50.0×)
m3 2006-04-09
Created by combining fifty-seven 20 s, f/2.9, ISO 400 photos. 25.0 mm eyepiece (50.0×)
M3 2009-05-09
Created by combining forty-six 20 s, ISO 1600 photos.
Prime focus (32.5×)

M5 15h 18.6m +2° 05´ Serpens 5.8 Sky Atlas 2000.0
charts 14, 15
M5
NGC 5904

2009-05-23
White balance = 6000K (Cloudy)
Noise reduction = Off
Prime focus (32.5×)
This is a combination of my sixty best photos. I removed a darkframe and flatfield, enhanced the contrast for each. I averaged the modified photos in six groups of ten and enhanced the contrast again. I averaged the combinations and enhanced the contrast. Finally, I cropped and scaled the image to 33.3%.

An easy object with this equipment. Note that the apparent distribution of stars is skewed to the southeast (lower left). I've had a fondness for M5 ever since I saw that Burnham mentions reading Isaac Asimov's Nightfall shortly after first viewing this object. Although Asimov probably didn't have M5 in mind when writing his story, this cluster and that story were linked in Burnham's mind and, in mentioning this, forever linked in mine. M5 is about 24,000 l.y. distant and 21´ across implying a diameter of 150 l.y.


M80 16h 17.0m -22° 59´ Scorpius 7.2 Sky Atlas 2000.0
chart 22
m80 NGC 6093

25.0 mm eyepiece (50.0×)
Created by averaging five 30 s, f/2.8, ISO 400 photos, then removing a flat-field and enhancing the contrast.

Like M4, M80 is near the brightest star in Scorpius, Antares, about 4° north-east. Both M4 and M80 are globular clusters and can be spotted with binoculars using Antares as a signpost, but the similarities end there. M80 appears as one of the smallest, most condensed globulars while M4 is one of the largest most diffuse. This is another favorite of mine because, many years ago, I independently found it one summer evening. Although my next trip to the library provided its identification, M80 gave me a taste of the excitement earlier astronomers must have felt. M80 is 36,000 l.y. distant and 8´ across implying it is about 80 l.y. in diameter.


M4 16h 23.6m -26° 32´ Scorpius 5.9 Sky Atlas 2000.0
chart 22
m4 2009-07-01 NGC 6121

2009-07-01
White balance = 6000K (Cloudy)
Noise reduction = Off
prime focus with reducer/corrector (54.2×)
Created from the twelve best 20 s - ISO 800 photos. I removed a dark frame and flat field from each photo and enhanced the contrast. The modified photos were then averaged in three groups of four and enhanced the contrast. I averaged the combined images, removed a background, enhanced the contrast, adjust the color balance to make truer whites and applied a 7×7 Gaussian blur. Finally I rotated to north-up, cropped and reduced the image.

Compared to other globular clusters, M4 appears to have a very low concentration of stars, but that means it is very well resolved even with small telescopes. The reason it appears so large and diffuse is that M4 is close, approximately 10,000 l.y. distant. With dark skies and binoculars, M4 is quite obvious about 1° west of Antares, the brightest star in Scorpius and little M80 should be in the field of view too. M4 is 34´ in diameter implying a diameter of about 100 l.y.



M13 16h 41.7m +36° 28´ Hercules 5.9 Sky Atlas 2000.0
chart 8

M13 2009-08-02

NGC 6205; Hercules Cluster

2009-08-02
White balance = 6000K (Cloudy)
Noise reduction = Off
prime focus with reducer/corrector (54.2×)

Created from the forty-three best 30 s, ISO 800 photos. I removed a dark frame and flat field from each photo, then enhanced the contrast. I averaged these together in five groups of seven and one group of eight and enhanced the contrast again. I then average the six groups and enhanced the contrast one last time. Finally I rotated the image to north-up, cropped it and reduced the scale by a factor of three. larger images in a new window.

Remarkable in any sized instrument, including binoculars, and visible by eye from a dark site. Many stars are resolved so M13 becomes more breathtaking in larger instruments. M13 is about 26,000 l.y. distant and 20´ across implying it is about 150 l.y. in diameter.



M12 16h 47.2m -01° 57´ Ophiuchus 6.7 Sky Atlas 2000.0
chart 15
m12
NGC 6218

2009-05-23
White balance = 6000K (Cloudy)
Noise reduction = Off
prime focus (32.5×)
This is a combination of my fifty-four best 20 s, ISO 1600 photos. I removed a darkframe and flatfield, enhanced the contrast for each. I averaged the modified photos in seven groups of nine and enhanced the contrast again. I averaged the combinations and enhanced the contrast. Finally, I cropped and scaled the image to 33.3%.

M12 and its nearby fraternal twin, M10, reside in a rich area of the sky. Of particular note is the near-by "high-velocity" Barnards Star. M12 is slightly more sparse and slightly closer than some other globular clusters, so its many stars are easily resolved. It is about 16,000 l.y. distant and 16´ across implying it is about 74 l.y. in diameter.


M10 16h 57.1m -04° 06´ Ophiuchus 6.6 Sky Atlas 2000.0
chart 15
m10
NGC 6218

2009-06-30
White balance = 6000K (Cloudy)
Noise reduction = Off
prime focus (32.5×)
This is a combination of my eighteen best 20 s, ISO 1600 photos. I removed a darkframe and flatfield, enhanced the contrast for each. I averaged the modified photos in three groups of six and enhanced the contrast again. I averaged the combinations and enhanced the contrast. Finally, I cropped and scaled the image to 33.3%.

Like its nearby fraternal twin M12, M10 clearly has a more "grainy" appearance than some of its siblings. Being somewhat sparse with many resolved stars, M10 is a wonderful sight in a small telescope at a dark site. As mentioned in the description of M12, this is in a rich area of the sky and worth examining by eye, binoculars or telescope. Although it appears smaller in smaller telescopes, M10 is about 20´ across. At a distance of 14,300 l.y., this implies a diameter of 83 l.y.


M92 17h 17.1m +43° 08´ Hercules 6.5 Sky Atlas 2000.0
chart 8
M92 2009-05-17 NGC 6341

White balance = 6000K (Cloudy)
Noise reduction = Off
Prime focus (32.5×)
Created from the thirty-five best 20 s, ISO 1600 photos. I removed a dark frame and flat field, enhanced the contrast of each photo. I averaged the modified photos in groups of five and enhanced the contrast. I averaged the combinations and enhanced the constrast. Finally I rotated to north-up and cropped the image.

An attractive, concentrated globular cluster but fated to be overshadowed by nearby M13. M92 is about 28,000 l.y. distant and 14´ across implying it is about 110 l.y. in diameter.


M22 18h 36.4m -23° 54´ Sagittarius 5.1 Sky Atlas 2000.0
chart 22

M22 2009-07-31

NGC 6656

White balance = 6000K (Cloudy)
Noise reduction = Off
prime focus using a reducer-corrector lens (54.2×)
Created from the fifty-one best 30 s - ISO 800 photos. I removed a dark frame and flat field from each photo and enhanced the contrast. The modified photos were then averaged seven groups of seven, the contrast was enhanced and a residual background removed. I averaged the combined images, enhanced the contrast and modified the white balance. Finally, cropped and reduced the image by a factor of five. Click the photo to display a larger image in a new window.

M22 is a moderately concentrated, bright globular cluster containing about 70,000 stars. It's total size is huge, 33´ across, about the size of the full Moon, but only the central portion is easily visible in small telescopes. The large apparent size is because M22 is one of the nearest globular clusters: only about 7,800 l.y. distant. This implies M22 is about 75 l.y. in diameter. It lies in the general direction of our galaxy's center so it's another jewel in this very rich part of the sky.



M54 18h 55.1m -30° 29´ Sagittarius 7.7 Sky Atlas 2000.0
chart 22

M54 2009-08-02

NGC 6715

2009-08-02
White balance = 6000K (Cloudy)
Noise reduction = Off
prime focus with reducer/corrector (54.2×)

Created from the thirty best 20 s, ISO 800 photos. I removed a dark frame and flat field from each photo, then enhanced the contrast. I averaged these together in six groups of five and enhanced the contrast again. I then average the six groups and enhanced the contrast one last time. Finally I rotated the image to north-up, cropped it and reduced the scale by a factor of three.

Although this little fellow appears small and unremarkable, it's rude to say so because this globular cluster is a visitor. It probably belongs to the newly discovered Sagittarius Dwarf Elliptical Galaxy which is interacting with our own Milky Way. The new data puts M54 at 87,400 l.y., much farther than the other globulars shown. If M54 were at a similar distance as the others, it would be one of the most spectacular objects in the sky.


M56 19h 16.6m +30° 11´ Lyra 8.3 Sky Atlas 2000.0
chart 8

M54 2010-07-10

NGC 6779

2010-07-10
White balance = 6000K (Cloudy)
Noise reduction = Off
prime focus (81.3×)

Created from the fifty-seven best 15 s, ISO 1600 photos. I removed calibration frames, enhanced the contrast and averaged the photos in groups of five or six. Next, I averaged the groups, removed a residual background and enhanced the contrast again. Finally I cropped the photo and reduced its size by a factor of 4.5.

M56 is well resolved but faint so it loses some of its punch. It gains it back again by being in a rich section of the sky. Scanning along the Milky Way searching for this globular is always worth the time. M56 is 8´ across, but I'm capturing only the brightest, inner 3´ or so. At an approximate distance of 46,000 l.y., 8´ translates to 90 l.y. in diameter.



M55 19h 40.0m -30° 58´ Sagittarius 7.0 Sky Atlas 2000.0
charts 22, 23
m55 NGC 6809

25.0 mm eyepiece (50.0x)
Created by combining seven 15 s, f/2.9, ISO 400 photos, then removing a flat-field and enhancing the contrast.

For year, astronomers debated whether M55 was a compact open cluster or a loose globular clusters. Better technology shifted opinion to it being a globular cluster and very long exposure photographs clearly show the globe shape. There just aren't enough brighter stars in the group to make it evident in smaller telescopes. M55 is 49,000 l.y. distant and 12´ across implying it is 170 l.y. in diameter.


M71 19h 53.8m +18° 47´ Sagitta 8.3 Sky Atlas 2000.0
charts 8, 16
m71 NGC 6838

25.0 mm eyepiece (50.0x)
Created by combining six 30 s, f/2.9, ISO 400 photos, then removing a flat-field and enhancing the contrast.

Like M55, the exact classification of M71, loose globular or compact open cluster, was uncertain until recently. Also like M55, it has been determined that M71 is a globular cluster. Being faint and not very compact in a rich field of stars makes M71 a challenge but it can be rewarding. M71 is 13,000 l.y. distant and 7´ across implying it is 30 l.y. in diameter.


M15 21h 30.0m +12° 10´ Pegasus 6.4 Sky Atlas 2000.0
charts 16, 17
m15 NGC 7078

2008-09-27 03:41 - 04:10 UTC
25.0 mm eyepiece & + barlow (80.2×)
Created by averaging twenty-one 60 s, f/2.8, ISO 400 photos in groups of four (and one group of five), removing a flat-field and enhancing the contrast. The groups were then averaged, the contrast enhanced again and an unsharp mask (3.0, 0.5, 0) applied.

The brightness and compactness of M15 makes it one of the most popular globular clusters in the north. M15 is 50,000 l.y. distant and 18´ across implying a diameter of 250 l.y. It contains a very small planetary nebula but because of resolution limits and chromatic abberation, there is no chance of detecting it in this photo.


M2 21h 33.5m +0° 49´ Aquarius 6.5 Sky Atlas 2000.0
charts 16, 17

M2 2010-11-06

NGC 7089

White balance = 6000K (Cloudy)
Noise reduction = Off
prime focus (81.3×)
Created from the fifty-three best 15 s - ISO 1600 photos. I removed calibration frames from each photo and enhanced their contrasts. I averaged all photos together, strongly enhanced the contrast and removed a residual background. The center of the cluster was saturated so I masked and combined the image with a less enhanced version of itself to show the structure towards the center of the cluster. Finally, I rotated the image to north-up and cropped the image by 4.5. Click the photo to display a larger image in a new window.

A large globular cluster with many resolved stars even in a small telescope. M2 is 15' across. At a distance of 55,000 l.y., this implies it is 240 l.y. in diameter.




Last modified: 2010-11-07