Astronauts
Astronomy
Constellation
Deep Sky Objects
Moon
Stargazing
Telescope
About Us Contact Us Privacy Policy Accuracy & Corrections Terms & Condition
COPYRIGHT. All contents of on the site comporting the Starlust branding are Copyright 2019. All rights reserved.
STARLUST.ORG / DEEP SKY OBJECTS

G1 Globular Cluster

G1 is the most luminous globular cluster in the entire Local Group of galaxies.
UPDATED JUN 26, 2024
mayall 2 globular cluster
mayall 2 globular cluster

Summer is the best time for astronomy. This is the season of clear nights with warm weather, and most of all, star parties. Hundreds of amateur astronomers gather under pristine skies to enjoy deep sky showpieces like the Lagoon Nebula or the bright globular star cluster M13. These are beautiful objects, which never fail to elicit a gasp when people see them for the first time. However, veteran observers might want to try something different…

How about a globular cluster located some 2.9 million light-years away, in the Andromeda Galaxy? Grab that telescope and prepare for some serious deep sky observing!

M31, the Andromeda Galaxy, contains numerous globular clusters, each closely packed together with up to a million stars. The brightest of these clusters is G1 (also known as Mayall II), and despite its visual magnitude of 13.7, it is the most luminous globular cluster in the entire Local Group of galaxies. G1 is located 170,000 light years from M31’s nucleus, and it has twice the mass of Omega Centauri. It’s estimated that the cluster consists of at least 300,000 old stars.

To locate G1, first center your telescope on the M32 galaxy, and from here move to the 5th-magnitude star 32 Andromedae. Star-hop another one and a half degrees to SAO 53986, the star marked on the coarse finder map. Once you have this star centered in the field, switch to the fine finder map and make your way to the cluster.

A 10-inch or slightly larger telescope should be enough to add G1 as a trophy in your observing log. At high magnification, the cluster appears as a tiny but obviously non-stellar patch, moderately brighter in the middle. A longer look will reveal two foreground stars on its southwestern edge.

Once you hone in on the correct location using the two charts below, switch to your highest power and sweep the field carefully. Remember that you are looking for a fuzzy patch only a few arcseconds wide, so give your eye plenty of time to dark-adapt and use averted vision.

MORE ON Starlust
On May 3, 2024, the Chang'e-6 probe launched and successfully gathered 1,935.3 grams of samples from the Moon's South Pole-Aitken (SPA) Basin.
1 day ago
The groundbreaking discovery involves fluvial sinuous ridges, or inverted channels, found mainly in Noachis Terra, a less-studied part of Mars' southern highlands.
1 day ago
Renowned for their swift, bright meteors and luminous trails, the Perseids are considered one of the most anticipated celestial events.
1 day ago
On July 20, the crescent moon will approach within a degree of the Pleiades star cluster, also known as the Seven Sisters, creating a stunning visual.
3 days ago
The pioneering project is set to transform our understanding of the Sun's mysterious interior.
4 days ago
Some theories suggest that our sun was in a similar state before the planets were all formed.
Jul 6, 2025
Discovered on July 1, the celestial body 3I/ATLAS is currently approaching Earth from the direction of the constellation Sagittarius.
Jul 6, 2025
Historically revered as Zeus's powerful eagle, bearing lightning and messages, this celestial constellation reaches its highest point in the sky during July and August.
Jul 6, 2025
With its unparalleled infrared capabilities, Webb now accomplishes what was once impossible, transforming our view of the cosmos from distant galaxies to our solar system.
Jul 5, 2025
An autonomous docking for the Progress 92 is anticipated around 5:27 p.m. EDT on Saturday, July 5.
Jul 4, 2025
This lift-off, from Kennedy Space Center's historic Launch Complex 39A (LC-39A), marked yet another crucial orbital mission for SpaceX.
Jul 2, 2025
The advanced LOFAR radio telescope enabled scientists to detect a massive cloud of high-energy particles around a galaxy cluster whose light traveled 10 billion years to Earth.
Jul 1, 2025
The new image specifically highlights the eastern reaches of Arcadia Planitia, a crucial area northwest of the massive Tharsis volcanic province.
Jun 30, 2025
The spiral galaxy UGC 11397, in the constellation Lyra, is home to a supermassive black hole aggressively consuming material at its core.
Jun 30, 2025
The New Shepard program's 33rd overall flight, a suborbital journey lasting approximately 10 minutes, lifted off from Launch Site One in West Texas at 9:39 a.m. CDT.
Jun 30, 2025
The dwarf galaxy NGC 4449, just 12.5 million light-years away in the constellation Canes Venatici, is a standout 'starburst galaxy.'
Jun 29, 2025
The new image combines data from across the electromagnetic spectrum, giving astronomers a complete picture of Andromeda's complex structure.
Jun 27, 2025
The NASA/ESA Hubble Space Telescope recently captured an image of the spiral galaxy IC 758, located 60 million light-years away in the constellation Ursa Major.
Jun 22, 2025
The Nancy Grace Roman Space Telescope, launching in 2027, will use gravitational lensing, a phenomenon Einstein predicted over a century ago, to study the mystery of dark matter.
Jun 22, 2025
Essential for galactic evolution, mergers impact the layout of gas, the motion of stars, and a galaxy's overall structure, ultimately leading to greater stellar mass.
Jun 21, 2025