At a Glance
Object: M45 – Pleiades / Seven Sisters
Type: Open Star Cluster
Constellation: Taurus
Distance: 444 light-years
Catalog: M45
Best Season: Fall
Messier 45, also known as the Pleiades or the Seven Sisters, is an open star cluster located in the constellation Taurus. Visible to the naked eye, it is one of the most recognizable star clusters in the night sky. The cluster contains hundreds of stars, but only six or seven are typically visible without a telescope.
The Pleiades are approximately 444 light-years away from Earth and are relatively young, formed about 100 million years ago. They are still surrounded by a faint reflection nebula, a cloud of gas and dust that reflects the light of the stars. This nebula, which appears bluish, is most visible through telescopes, adding to the cluster’s striking appearance.
The Pleiades are often referenced in various cultures, appearing in Greek mythology, where they represent seven sisters pursued by Orion. This cultural significance has led to their mention in folklore, stories, and art across different civilizations.
The stars in Messier 45 are mostly hot, blue B-type stars, which are young and massive. The brightest stars in the cluster include Alcyone, Maia, and Electra. Since the cluster is relatively close to Earth, it has been extensively studied, providing insights into the life cycles of stars.
Messier 45 is also important for navigation and has been used as a celestial marker for centuries. Its brightness and position in the sky have made it a crucial feature for understanding both the cosmos and ancient human cultures.
In summary, Messier 45 is not only a beautiful sight in the night sky but also a significant astronomical and cultural object.
Capture Details
| Telescope | William Optics Z73 |
| Reducer/Flattener | William Optics Flat6aiii |
| Filter | Optolong L-Pro Optolong L-Extreme |
| Camera | ZWO ASI294 MC Pro ZWO ASI183MC Pro |
| Mount | Skywatcher EQM-35 Pro |
| Total Captured | 308 |
| Total Time | 10 hours 7 minutes |
| Capture Software | N.I.N.A. |
| Guiding | PHD2, ZWO asi120mm mini, |
| Processed in | PixInsight |
Backyard Capture Notes
M45, the Pleiades, is a beautiful but deceptively challenging backyard target. The bright blue stars are easy to capture, but the delicate reflection nebulosity around them takes patience, clean data, and careful processing. From suburban skies, that faint dusty glow can be difficult to separate from background light pollution.
The biggest challenge with M45 is balancing the bright stars against the soft blue haze surrounding them. Push the stretch too far and the stars can become harsh; hold back too much and the nebulosity disappears. It is a rewarding target because the final image shows both the brilliance of young stars and the faint dust clouds they are lighting up as they pass through space.