The nebula M20 in Sagittarius, also known as NGC 6514. It is a combined emission and reflection nebula, extending for nearly ½°. The Trifid takes its name from three dark lanes of dust that trisect it. It is centred on the multiple star HN 40, the brightest members of which evidently illuminate it. The Trifid lies 5000 l.y. away.
http://www.eso.org/public/images/eso0930a/http://www.spitzer.caltech.edu/images/1367-ssc2005-02a1-Visible-Light-Pictureof-the-Trifid-Nebula
- Meudon Observatory
- Mexican Revolution (1910–40)
- Mexican–American War (1846–48)
- Mexico
- Meyer group
- Meyerhof, Otto Fritz
- Meyer, Julius Lothar
- Meyer, Karl
- Meyer, Viktor (1848–97)
- Mečiar, Vladimir (1942–)
- MF
- MFCC
- MFLOPS
- Mflops
- MFM
- M-fold
- Mg#
- MGA
- mgf
- MGLAB
- MHC
- MHC class II protein
- MHC class I protein
- MHD
- mho