M 7
The M 7 is a large, naked eye open star cluster in the constellation Scorpius. At a distance of 800 to 1000 light years, it contains about 30 stars. The integrated brightness of M 7 is apparent magnitude 3.3.
The cluster is about 220 million year in age. Known since antiquity, it was first described by Ptolemy in 130 AD.
Technical Details
- Object: M 7
- Object Type: Open Star Cluster
- Other Names: NGC 6475, Ptolemy Cluster
- Date/Time: 2010 Apr 14 at 11:17 UTC
- Location: Bifrost Astronomical Observatory, Portal, AZ
- Telescope: Nikkor 300mm F/2.8 Lens
- Mount: Astro-Physics 1200GTO
- Camera: Nikon D300
- Exposure: 4 x 240s, f/2.8, ISO 800
- File Name: M07-01w.jpg
- Processing: Stack of 4 Images, Cropping, Levels, Unsharp Mask (Photoshop CS5)
- Original Image Size: 2848 x 4288 pixels (12.2 MP); 9.5" x 14.3" @ 300 dpi
- Rights: Copyright 2010 by Fred Espenak. All Rights Reserved. See: Image Licensing.