Unistellar Citizen Astronomers are invited to participate in this week’s special quest to observe star clusters from the Messier Catalogue, in preparation for our upcoming Messier Marathon!
The Messier Catalogue is a set of 110 deep sky objects which includes galaxies, nebulae, and star clusters. The catalogue was published by French astronomer Charles Messier in 1774.
Below you’ll find a selection of some of the best eVscope observations of star clusters from the Messier Catalogue.

eVscope image captured by Unistellar Citizen Astronomer David Rowe, from Wimborne, United Kingdom
M45: The Pleiades
The Pleiades (M45) is an open star cluster, meaning that the stars within the cluster formed together and are loosely bound by gravity. The Pleiades is the closest Messier object to Earth! This colorful cluster is home to about 3,000 stars including extremely luminous, hot, blue stars. The names of the brightest stars are the Seven Sisters in Greek mythology, the Pleiades, and their parents, Pleione and Atlas.
Quick Facts and Observing Tips:
- Distance from Earth: 444 light years
- Constellation: Taurus
- Size: 16 light years
- Discovery: Known since ancient times, no known discoverer
- Search for “M45” or “Pleiades” in the Explore tab of the Unistellar app.
- Depending on the sky quality at your location, you may want to leave the Enhanced Vision mode on for at least a few minutes
- Recommended Bortle Class is 6 or lower.

eVscope image captured by Unistellar Citizen Astronomer David Rowe, from Wimborne, United Kingdom
M44: The Beehive Cluster
The Beehive Cluster (M44), is one of the closest star clusters to us. This open cluster is a colorful swarm of about one thousand stars! It is only 600 million years old, which is very young compared to the age of our solar system (4.5 billion years old)! Did you know that the Kepler Space Telescope discovered six exoplanets orbiting stars within M44? In 2012, two of those six were the first exoplanets detected in a star cluster that orbit stars similar to our own Sun! Those exoplanets, Pr0201 b and Pr0211 b, are known as Hot Jupiters — gas giants that orbit close to their stars.
Quick Facts and Observing Tips:
- Distance from Earth: 577 light years
- Constellation: Cancer
- Size: 23 light years
- Discovery: Known since ancient times, no known discoverer
- Search for “M44” or “Beehive Cluster” in the Explore tab of the Unistellar app.
- Depending on the sky quality at your location, you may want to leave the Enhanced Vision mode on for at least a few minutes
- Recommended Bortle Class is 6 or lower.

eVscope image captured by Unistellar Citizen Astronomer Gerd Waloszek, from Germany
M37: Open Cluster in Auriga
Messier 37 (M37) contains about 500 stars and is about 500 million years old, which is old, even for a star cluster! The entire mass of the cluster is 1,500 times the mass of our Sun. When viewed from Earth, M37 lies in the direction opposite to our Milky Way Galaxy’s center. It takes M37 about 220 million years to make one orbit around our Milky Way’s center. For reference, our solar system takes 240 million years to make one orbit around our Milky Way.
Quick Facts and Observing Tips:
- Distance from Earth: 4,500 light years
- Constellation: Auriga
- Size: 20-25 light years
- Discovery: Before 1654 by astronomer, Giovanni Battista Hodierna
- Search for “M37” in the Explore tab of the Unistellar app.
- Depending on the sky quality at your location, you may want to leave the Enhanced Vision mode on for at least a few minutes.
- Recommended Bortle Class is 6 or lower.

eVscope image captured by Unistellar Citizen Astronomers Nicole Ruel and Jacques Bérard, from Québec
M5: Globular Cluster in Serpens
Messier 5 (M5) is a globular cluster, a densely packed group of hundreds of thousands of stars that all formed together at the same time. M5 spans 165 light years across, making it one of the largest known globular clusters. M5 is not only one of the largest known globular clusters, but one of the oldest as well. M5 is almost as old as our known universe! We know this because some of its original stars are still around. M5 is made of at least 105 variable stars — stars that change their brightness. The change is caused by their luminosity actually changing or by an external factor, like a companion star eclipsing it. Most of M5’s variable stars are type RR Lyrae, which are used as standard candles to measure large distances across space.
Quick Facts and Observing Tips:
- Distance from Earth: 24,500 light years
- Constellation: Serpens
- Size: 165 light years
- Discovery: 1702 by astronomer Gottfried Kirch
- Search for “M5” in the Explore tab of the Unistellar app.
- Depending on the sky quality at your location, you may want to leave the Enhanced Vision mode on for at least a few minutes.
- This will be a challenging object to observe since it will be visible after midnight.
- Recommended Bortle Class is 7 or lower.
M13: The Hercules Globular Cluster
The Hercules Globular Cluster (M13) is home to several hundreds of thousands of stars and is about 12 billion years old! For reference, our visible universe is about 13.8 billion years old. The stars within M13 are so densely packed together that sometimes they collide and form new stars, called blue stragglers! In 1974, an interstellar radio message known as the Arecibo Message was broadcast into space, aimed at M13! The pictorial message was sent from the Arecibo radio telescope in Puerto Rico and contained information about humanity and Earth. Late last year, the telescope was decommissioned and then collapsed before controlled demolition could begin.
Quick Facts and Observing Tips:
- Distance from Earth: 25,000 light years
- Constellation: Hercules
- Size: 145 light years
- Discovery: 1714 by astronomer, Edmond Halley
- Search for “M13” or “Hercules Globular Cluster” in the Explore tab of the Unistellar app.
- Depending on the sky quality at your location, you may want to leave the Enhanced Vision mode on for at least a few minutes.
- This will be a challenging object to observe since it will be visible after midnight.
- Recommended Bortle Class is 7 or lower.
We encourage you to share your observations and join the conversation through our Facebook, Instagram and Twitter pages using the hashtag #UnistellarChallenge!
If you’d like to send us your observations by email, send them to community@unistellaroptics.com.
Clear skies! 🔭