1. Messier 5 – An Ancient Globular Cluster in Serpens
At 13 billion years old, Messier 5 is one of the oldest globular clusters in the Milky Way. It can be found low in the sky to the west of Serpens Caput. If you imagine an equilateral triangle pointing west with two corners at Epsilon and Mu Serpens then M5 is at the other corner of the triangle on the western side. M5 is one of the largest known globular clusters. According to some estimates it may contain as many as 500,000 stars.
2. The Great Cluster in Hercules (Messier 13)
Messier 13 is probably the best known globular cluster in the Messier list. It can be found on the Bootes side of the Keystone in Hercules, about two thirds of the way from Zeta Herc to Eta Herc. M13 contains around 300,000 stars and is about 145 light years in diameter at a distance of 25,000 light years from Earth.
3. The Summer Beehive Cluster (IC4665)
A fine binocular cluster that is almost twice the diameter of the full moon. It can be found in the constellation of Ophiuchus, about one degree north east of Beta Ophiuchi in the same binocular field as the star itself. The cluster consists of around a dozen 7th to 8th magnitude stars. It is less than 40 million years old and lies about 1,400 light years from Earth.
4. Messier 10 – A Globular Cluster in Ophiuchus
Woolly mammoth were still grazing the tundra when the light from Messier 10 started it’s journey to your eyes! This cluster can be found just over two binocular fields in the direction of Aquila. M10 is estimated to be 11.4 billion years old and 14,300 light years away from Earth.
5. Messier 12 – An Ancient Globular Cluster in Ophiuchus
At 12.7 billion years old, Messier 12 is 92% as old as the universe itself! You should be able to find it in the same binocular field as M10 above, a little to the north west. It is located about 15,700 light years from Earth.
6. Epsilon Lyrae – A Binary Star System
Epsilon Lyrae is a double double star. You should be able to find it in the same binocular field as Vega. Lying at a distance of around 162 light years from Earth, the two stars take hundreds of thousands of years to orbit each other. A telescope, with more magnification, will reveal that each star is a double itself. In fact this system is now thought to contain as many as ten stars.
7. The Ring Nebula (Messier 57)
One of the most famous objects in the night sky, Messier 57 is a classic planetary nebula. It can be found about halfway between Beta and Gamma Lyrae. Whilst M57 is easily visible in binoculars you might well miss it. Because the ring is only 80 arc seconds across it will appear as a faint, slightly out of focus star. A telescope is needed to see the ring itself.
8. Alya – A Close Binary Star
A challenging double star for binoculars. Alya (Theta Serpentis) is the last bright star (magnitude 4.6) in the tail of Serpens. Close examination will reveal that it is a double star. You will need to hold your binoculars very steady or mount them on a tripod for this one! Both stars are quite similar to one another and have an orbital period of at least 14,000 years.
9. Graff’s Cluster (IC4756)
This big showy open cluster can be found about one binocular field west of Theta Serpentis. It is about 1,300 light years away from earth and has around 80 members stars.
10. Barnard’s “E” – A Dark Nebula in Aquila
A mysterious dark “E” can be found silhouetted against the faint background glow of the Milky Way in Aquila on clear moonless nights. Barnard’s “E” is about half a binocular field to the north west of Altair. It is named after Edward Barnard (1857 – 1923) who compiled a list of dark markings in the sky.
11. Messier 71 – A Globular Cluster in Sagitta
There are not many constellations that will fit into a binocular field of view, but Sagitta (The Arrow) is one of them. Look carefully along the shaft of the arrow. Halfway between Gamma and Delta you should spot the globular cluster M71. It is relatively close to us for a globular, lying only 12,000 light years away. It is also one of the youngest globular clusters at around 9 – 10 billion years old.
12. The Dumbbell Nebula (Messier 27)
The Dumbbell Nebula is the biggest and brightest planetary nebula in the Messier catalogue. It lies around half a binocular field north of Gamma Sagittae. It will appear as a small disk just below the central star of a distinctive “M” shaped asterism. The Dumbbell Nebula is about 1,360 light years away and has a diameter of around 3 light years.
13. The Coathanger (Brocchi’s Cluster)
The Coathanger is an unmistakable asterism despite being upside down! Find it about one binocular field to the north west of Alpha Sagittae. Although it’s stars appear to be close together, they are a chance alignment at very different distances from us.
14. Messier 2 – A Globular Cluster in Aquarius
At 13 billion years old and a diameter of 175 light years, Messier 2 is one of the oldest and largest globular clusters in the Milky Way. It is about one binocular field north of Beta Aquarii. Lying at a distance of 37,500 light years from Earth, it contains around 150,000 stars.
15. The Great Pegasus Cluster (Messier 15)
M15 is one of the most densely packed globular clusters in the Milky Way. First find the Great Square of Pegasus. Now look for Epsilon Pegasi to the west of the square. Finally move one binocular field towards Cygnus to find M15. It has over 100,000 stars within it’s 175 light years diameter.
16. The Engagement Ring
The Engagement Ring is one of the prettier asterisms. It can be found in the constellation of Ursa Minor (The Little Bear). The ring is a rough circle of 8th and 9th magnitude stars opposite the body of Ursa Minor. Polaris itself is the sparkling diamond in the ring. It is visible all night long and all year round from our latitude.
17. Omicron Cygni – A Triple Star
A colourful triple star system. Omicron Cygni is about one binocular field to the west of Deneb (Alpha Cygni), the top left star of the Summer Triangle. It consists of a golden magnitude 3.8 star widely separated from a bluish – white companion at magnitude 4.8. These two are an optical double. However almost lost in the glow of the magnitude 3.8 star is a third magnitude 7.0 star. This is an eclipsing binary pair with an orbital period of around 10 years.
18. Messier 39 – An Open Cluster
The light from Messier 39 started it’s journey towards Earth at around the time of the Norman Conquest! M39 can be found about two binocular field widths to the north east of Deneb (Alpha Cygni). It has about 30 member stars and is 200 – 300 million years old.
19. Barnard 168 – A Dark Nebula
A finger of darkness against the background stars of the Milky Way. From M39 move half a binocular field to the east to find it. This is B168, a dark nebula of 2,500 solar masses that is about 500 light years away from Earth.
20. Caldwell 16 (NGC7243) – An Open Cluster in Lacerta
Caldwell 16 was born when dinosaurs ruled the earth around a hundred million years ago. First of all find the constellation of Lacerta that lies halfway between Cygnus and Cassiopeia. From Alpha Lacertae. move about half a binocular field towards Deneb to find Caldwell 16. C16 is around 2,800 light years away from Earth.
21. NGC6939 – An Ancient Open Cluster in Cepheus
NGC6939 is one of the oldest open clusters in the Milky Way at around 1.2 billion years old. It can be found just over one binocular field west of Alpha Cephei just beyond Eta Cephei. It is around 3,800 light years away.
22. The Fireworks Galaxy (Caldwell 12, NGC6946)
The Fireworks galaxy is a starburst galaxy – so called because it has a far higher rate of star formation than most other galaxies. It can be found in the same binocular field as NGC6939, just to the south east. Although visually almost next door, it is over 5,000 times as far away as NGC6939 at around 22 million light years. Nine supernovae have been observed in it over the past century.
23. Herschel’s Garnet Star ( Mu Cephei)
Herschel’s Garnet star is one of the reddest carbon stars north of the equator. It lies just over a binocular field width south of Alpha Cephei. Herschel’s Garnet Star is a red supergiant. If it were at the centre of the solar system it’s outer atmosphere would extend past Jupiter!