Messier 2 – Globular Cluster

Messier 2 – Globular Cluster

Detailed photo taken by Hubble Telescope. Credit: ESA/Hubble & NASA, G. Piotto et al.

The second object of the Messier Catalogue is the called Messier 2 or Globular Cluster. It is one of the largest globular clusters in our Milky Way galaxy. It is located some 37,500 light years away from us and it lies on the Constellation of Aquarius.

It consists of around 150,000 stars concentrated in an dense area with approximately 175 light years diameter. It's most bright stars are red and yellow giant stars and it is considered one of the oldest globular clusters in our Milky Way with an age of around 13 billion years old!

Image of M2 taken by the Galaxy Evolution Explorer Telescope. Image Credit Image credit: NASA/JPL/California Institute of Technology

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Facts

• Type: Globular cluster

• Magnitude: 6.25

• Right Ascension : 21h 33m27.2s

• Declination: -00°44'20.4"

• Distance: 37,500 light years

• Constellation: Aquarius

• Best viewed during: Autumn

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Observation

Locating the Globular Cluster can be tricky, as it lies above the Aquarius Constellation in a low density area. The Aquarius constellation is best visible between months July and November, being at its peak during October.

The two brightest stars of the Constellation are called Alpha Aquarii and Beta Aquarii and they are both yellow supergiants.

The Messier 2 Globular Cluster lies around 4.4 degrees above the Beta Aquarii. One of the easiest ways of calculating these 4.4 degrees, is to extend your hand to the direction you want and then use your three middle fingers from Beta Aquarii.

How to locate it

First you have to locate Alpha and Beta Aquarii which are the brightest stars in the Aquarius Constellation.

Once you locate those two bright stars, you can create a Right triangle, on which the right angle will be next to the Globular Cluster.

Alternatively, you could locate Beta Aquarii and then find it about 4.5 degrees above, using the finger method.