The Seven Sisters

The Pleiades, also known as the Seven Sisters or M45, is one of the nearest star clusters to Earth at only 444 light-years away. This young open cluster is approximately 100 million years old.

About This Image

This image reveals the beautiful blue reflection nebulosity surrounding the brightest stars of the Pleiades:

• Blue Reflection Nebula: Dust clouds illuminated by the hot blue stars
• Bright Stars: The seven brightest stars visible to the naked eye
• Fainter Members: The cluster contains over 1,000 confirmed members
• Delicate Structures: Wispy nebulosity throughout the field

Imaging Details

Equipment

• Telescope: William Optics RedCat 51
• Camera: ZWO ASI2600MC Pro
• No Filter: Natural color imaging

Acquisition

• Total Integration: 4 hours
• Shorter Exposures: 180s to prevent star blooming
• Many Frames: 80 frames for smooth gradients

The Blue Reflection Nebula

The nebulosity around the Pleiades is not a remnant of the cluster's formation, as once thought, but rather a dust cloud the cluster is currently passing through. The blue color comes from dust grains scattering starlight, similar to why Earth's sky is blue.

Cultural Significance

The Pleiades have been known since antiquity and appear in the mythology of cultures worldwide. They mark the beginning of the sailing season in Greece and are prominent in Japanese and Native American traditions.