Lagoon (M8) and Trifid (M20) Nebulae
The Lagoon and Trifid Nebulae are a pair of bright emission nebulae in the constellation Sagittarius.
The Lagoon Nebula (M8) is an H II region or interstellar cloud that glows red due to ionized hydrogen as it recombines with lost electrons. The nebula's distance is estimated at 5000 light years which would make its physical diameter about 100 light years. The Lagoon is an active stellar nursery and contains a number of dark globules (collapsing clouds of protostellar material). From Earth, the apparent size of the Lagoon is 40 by 90 arc-minutes and it shines at apparent magnitude +6.0.
The Trifid Nebula (M20) consists of a conspicuous emission nebula as well as a remarkable reflection nebula. The emission nebula glows red in the characteristic color of ionized hydrogen while the reflection nebula is blue from nearby hot, young stars. The Trifid Nebula gets its name from its three-lobed appearance. The distance of the nebula is estimated at 5000 light years but there are large uncetrainties in this value. The apparent size of the Trifid is 28 arc-minutes and its apparent magnitude is +6.3.
- Object: Lagoon and Trifid Nebulae
- Object Type: Bright Emission Nebula
- Other Names: Lagoon: M 8, NGC 6523, Sharpless 25; Trifid: M 20, NGC 6514, Sharpless 30
- Date/Time: 2010 Apr 10 at 10:50 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: M08M20-01w.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.