Messier 21-30

 

M21 (NGC 6531), Sagittarius. RA 18:04 6, DEC -22:30

M21 is an open cluster around 3,000 light years away from Earth, with 57 stars in a concentrated cluster. M21 is only 4.6 million years old. This open cluster in Sagittarius has a magnitude of 6.5, it is very close to the Trifid Nebula and it’s edges can sometimes be seen in Trifid Nebula photos.

 

 

M22 (NGC 6656), Sagittarius. RA 18:36 4, DEC -23:54

M22 is a globular cluster at only 10,600 light years away, which makes it one of the nearest globulars to us. This ball of stars has 70,000 suns and a tight core. This one is the brightest globular cluster in the northern hemisphere at magnitude 5.5. M22 is one of a rare breed of globulars as it is only one of 4 in our Galaxy that contains a planetary nebula. The others are NGC 6411, M15, and Palomar 6. M22 even outshines the Great Hercules Cluster and can be seen with the naked eye.

 

M23 (NGC 6494), Sagittarius. RA 17:56 8, DEC -19:01

M23 is another Messier object in the rich Milky Way star fields, an open cluster 2,150 light years away, and containing about 150 stars. M23 is at magnitude 6.9

 

 

M24, The Sagittarius Star Cloud. RA 18:16 9, DEC -18:29

M24 is not really a deep sky object but a gigantic star cloud in the Milky Way, containing star clusters stretching off thousands of light years along our line of sight. In this area of the Milky Way interstellar dust forms patches around 25 light years across. The dust can block out star clouds, but clear gaps and windows in this dust can reveal these star clouds. M24 is a chance window through an interstellar dust cloud, uncovering the richness of our Galaxy.

 

 

M25 (IC 4725), Sagittarius. RA 18:31 6, DEC -19:15

M25 is an open cluster 2,000 light years away, about 90 million years old, and around 19 light years across. A Delta Cephei type variable star called U Sagittarii is a member. M25 is prominent even in small telescopes with a magnitude of 4.6

 

 

M26 (NGC 6694), Scutum. RA 18:45 2, DEC -09:24

M26 is an open cluster 5,000 light years away,22 light years across, and 89 million years old. This is a nice cluster although it’s neigbour M11 is better. There are less stars in M26 in the area around the nucleus, although it is likely that more stars do exist here but are blocked out by interstellar dust. M26 is at magnitude 8.0

 

 

M27, The Dumbbell Nebula (NGC 6853), Vulpecula. RA 19:59 6, DEC 22:43

M27 The Dumbbell Nebula is a planetary nebula and one of, if not the best planetary nebula in the sky at a distance of 1,360 light years away. M27 was originally a star that fitted into the same mass scale as our Sun, it had come to the end of it’s life and expelled it’s outer layers into space as our Sun will eventually do. The nebula is expanding at 31 km/sec, it’s central star is an extremely hot white dwarf at magnitude 13.5, and is larger than any known white dwarf star. M27 has a magnitude of 7.5

 

M28 (NGC 6626), Sagittarius. RA 18:24 33, DEC -24:52 11

M28 is a globular cluster 18,000 to 19,000 light years from Earth, with a diameter of 60 light years, although it’s neighbour M22 out does M28 with it’s larger size. M28 harbours a millisecond pulsar that spins around on it’s axis once every 11 milliseconds. This globular cluster has a magnitude of 7.6

 

 

M29 (NGC 6913), Cygnus. RA 20:23 9, DEC 38:32

M29 is an open cluster with a diameter of just 11 light years, it is in a cluttered area of the Milky Way  and one of the less remarkable clusters. It is about 10 million years old and is travelling towards the solar system at 28 km/sec. M29 is seen best in low power scopes and binoculars. This open cluster has a magnitude of 7.1

 

M30 (NGC 7099), Capricornus. RA 21:40 4, DEC -23:11

M30 is a dense globular cluster 26,000 light years away, and 90 light years in diameter. This cluster has undergone “core collapse” whereby the core is proportianally very much smaller than the rest of the cluster. Some other globulars have the same characteristic, this is due to the stars in the centre crowding around a massive object, possibly a black hole. The brightest of this ball of stars can be seen in telescopes starting at 4 inch aperture. This is a magnitude 7.2 object.