A guide to what's up in the sky for Southern Australia

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M15—Globular Cluster in Pegasus (2nd Oct 2026)

Messier 15 or M15 is a globular cluster in the constellation Pegasus. It was included in Charles Messier's catalogue of comet-like objects in 1764

At an estimated 12.5 billion years old, it is one of the oldest known globular clusters. It is 35,700 light-years from Earth, and 175 light-years in diameter. It has an absolute magnitude of −9.2, which translates to a total luminosity of 360,000 times that of the Sun.

Messier 15 is one of the most densely packed globulars known in the Milky Way galaxy.

Home to over 100,000 stars, and with a magnitude 6.2, M15 is just below naked eye visibility under dark skies and can be observed with binoculars or a small telescope, appearing as a fuzzy star. Telescopes with a larger aperture will start to reveal individual stars.