There are two main types of star clusters – globular star clusters and open (or galactic) star clusters.
Star clusters are particularly beautiful objects to view through a small telescope, or a good pair of binoculars.
Globular Star Clusters
Globular star clusters are spherical collections of stars, tightly bound together by gravity. They are generally found in the halo of a galaxy.
Open Star Clusters
Open stars, as the name suggests, are much less dense than globular clusters and are more disparate and amorphous in shape. Open star clusters are also known as galactic star clusters, since they are generally found within the disk of a galaxy.
List of Globular Star Clusters from the Messier Catalogue
by apparent magnitude
Below is a list of the equatorial coordinates of some of the brightest globular star clusters.
| Cat Number | Const | App Mag |
RA | Dec |
|---|---|---|---|---|
| M22 / NGC 6656 | Sagittarius | 5.1 | 18h36m23.94s | –23°54′17.1″ |
| M13 / NGC 6205 | Hercules | 5.8 | 16h41m41.24s | +36°27′35.5″ |
| M4 / NGC 6121 | Scorpius | 5.9 | 16h23m35.22s | –26°31′32.7″ |
| M71 / NGC 6838 | Sagitta | 6.1 | 19h53m46.49s | +18°46′45.1″ |
| M3 / NGC 5272 | Canes Venatici | 6.2 | 13h42m11.62 | +28° 22′ 38.2″ |
| M15 / NGC 7078 | Pegasus | 6.2 | 21h29m58.33s | +12°10′01.2″ |
| M2 / NGC 7089 | Aquarius | 6.3 | 21h33m27.02s | –00°49′23.7″ |
| M92 / NGC 6341 | Hercules | 6.3 | 17h17m07.39s | +43°08′09.4″ |
| M10 / NGC 6254 | Ophiuchus | 6.4 | 16h57m8.92s | −04°05′58.07″ |
| M5 / NGC 5904 | Serpens | 6.7 | 15h18m33.22s | +02°04′51.7″ |
| M55 / NGC 6809 | Sagittarius | 7.4 | 19h39m59.71s | −30°57′53.1″ |
| M62 / NGC 6266 | Ophiuchus | 7.4 | 17h01m12.60s | –30°06′44.5″ |
| M19 / NGC 6273 | Ophiuchus | 7.5 | 17h02m37.69s | −26°16′04.6 |
| M12 / NGC 6218 | Ophiuchus | 7.7 | 16h47m14.18s | –01°56′54.7″ |
| M28 / NGC 6626 | Sagittarius | 7.7 | 18h24m32.89s | –24°52′11.4″ |
| M30 / NGC 7099 | Capricornus | 7.7 | 21h40m22.12s | –23°10′47.5″ |
| M80 / NGC 6093 | Scorpius | 7.9 | 16h17m02.41s | –22°58′33.9″ |
| M14 / NGC 6402 | Ophiuchus | 8.3 | 17h37m36.15s | –03°14′45.3″ |
| M53 / NGC 5024 | Coma Berenices | 8.3 | 13h12m55.25s | +18°10′05.4″ |
| M56 / NGC 6779 | NGC 6779 | 8.3 | 19h16m35.57s | +30°11′00.5″ |
| M69 / NGC 6637 | Sagittarius | 8.3 | 18h31m23.10s | −32°20′53.1″ |
| M9 / NGC 6333 | Ophiuchus | 8.4 | 17h19m11.78s | –18°30′58.5″ |
| M54 / NGC 6715 | Sagittarius | 8.4 | 18h55m03.33s | −30°28′47.5″ |
| M79 / NGC 1904 | Lepus | 8.6 | 05h24m10.59s | −24°31′27.3″ |
| M107 / NGC 6171 | Ophiuchus | 8.9 | 16h32m31.86s | –13°03′13.6″ |
| M70 / NGC 6681 | Sagittarius | 9.1 | 18h43m12.76s | –32°17′31.6″ |
| M75 / NGC 6864 | Sagittarius | 9.2 | 20h06m04.75s | −21°55′16.2″ |
| M72 / NGC 6981 | Aquarius | 9.4 | 20h53m27.70s | –12° 32′ 14.3″ |
| M68 / NGC 4590 | Hydra | 9.7 | 12h39m27.98s | –26°44′38.6″ |
List of Open Star Clusters from the Messier Catalogue
by apparent magnitude
Below is a list of the equatorial coordinates of some of the brightest open star clusters.
| Cat Number | Name / Const | App Mag |
RA | Dec |
|---|---|---|---|---|
| M45 | Pleiades / Taurus | 1.6 | 3h47m24s | +24°7 |
| M7 / NGC 6475 | Ptolemy Cluster / Scorpius | 3.3 | 17h53m 51.2s |
–34°47′34″ |
| M44 / NGC 2632 | Beehive Cluster / Cancer | 3.7 | 08h40.4m | 19°59′ |
| M6 / NGC 6405 | Butterfly Cluster / Scorpius | 4.2 | 17h40.1m | −32°13′ |
| M47 / NGC 2422 | Puppis | 4.2 | 07h36.6m | -14°30′ |
| M41 / NGC 2287 | Canis Major | 4.5 | 06h46.0m | −20°46′ |
| M25 / IC 4725 | Sagittarius | 4.6 | 18h31.6m | −19°15′ |
| M52 / NGC 7654 | Cassiopeia | 5.0 | 23h24.2m | +61°35′ |
| M35 / NGC 2168 | Gemini | 5.3 | 06h09.1m | +24°21′ |
| M34 / NGC 1039 | Perseus | 5.5 | 02h42.1m | +42°46′ |
| M39 / NGC 7092 | Cygnus | 5.5 | 21h31m42s | +48°25′ |
| M48 / NGC 2548 | Hydra | 5.5 | 08h13.7m | -05°45′ |
| M50 / NGC 2323 | Monoceros | 5.9 | 07h03.2m | −08°20′ |
| M93 / NGC 2447 | Puppis | 6.0 | 07h44.6m | −23°52′ |
| M46 / NGC 2437 | Puppis | 6.1 | 07h41.8m | −14°49′ |
| M67 / NGC 2682 | Cancer | 6.1 | 08h51.4m | +11°49′ |
| M37 / NGC 2099 | Auriga | 6.2 | 5h52m18s | +32°33′02″ |
| M11 / NGC 6705 | Wild Duck Cluster / Scutum | 6.3 | 18h51.1m | −06°16′ |
| M36 / NGC 1960 | Auriga | 6.3 | 5h36m12s | +34°08′4″ |
| M21 / NGC 6531 | Sagittarius | 6.5 | 18h04.6m | −22°30′ |
| M23 / NGC 6494 | Sagittarius | 6.9 | 17h56.8m | −19°01′ |
| M29 / NGC 6913 | Cygnus | 7.1 | 20h23m56s | +38°31.4′ |
| M38 / NGC 1912 | Auriga | 7.4 | 5h28m42s | +35°51′18″ |
| M103 / NGC 581 | Cassiopeia | 7.4 | 01h33.2m | +60°42′ |
| M18 / NGC 6613 | Sagittarius | 7.5 | 18h19.9m | −17°08′ |
| M26 / NGC 6694 | Scutum | 8.0 | 18h45.2m | −09°24′ |