Great Rift (astronomy)
In astronomy, the Great Rift (sometimes called the Dark Rift, or less commonly the Dark River), is an aggregation of overlapping, non-luminous, molecular dust clouds that lie between the Solar System and the Sagittarius Arm of the Milky Way galaxy. They form a dark lane through the starry path of the Milky Way which, seen from Earth, is a hazy band of white light, some 30° wide, arching across the night sky. These clouds are located about 800–1,000 parsecs (2,600–3,300 ly) from Earth.[1] The clouds are estimated to contain about 1 million solar masses of plasma and dust.[2]
Properties
To the naked eye, the Great Rift appears as a dark lane that divides the bright band of the Milky Way lengthwise, through about one-third of its extent, and is flanked by lanes of numerous stars.[2]
Starting at the constellation of Cygnus, where it is known as the Cygnus Rift or Northern Coalsack, the Great Rift stretches to Aquila; to Ophiuchus, where it broadens out; to Sagittarius, where it obscures the Galactic Center; and finally to Centaurus. One of the most important regions it obscures is the Cygnus OB2 association, a large cluster of young stars and one of the largest regions of star formation near Earth. Similar dark rifts can be seen in many edge-on galaxies, such as NGC 891 in Andromeda and NGC 4565 (the Needle Galaxy) in Coma Berenices.[3]
Gallery
- This image shows the dusty lanes dotted with colorful nebulae between Sagittarius and Scorpius.
- This radio image shows intense radio emissions emanating from the Milky Way's center.
- This view of the Milky Way and Great Rift was taken from ESO's Very Large Telescope atop Cerro Paranal, Chile.
- This image shows a mysterious ring composed of very dense and cold gas and dust around the Galactic Center.
- This image shows the dense and compact regions where gas and dust clump together in the galaxy.
See also
Notes
- ↑ Green, Gregory M; Schlafly, Edward F; Finkbeiner, Douglas P; Rix, Hans-Walter; Martin, Nicolas; Burgett, William; Draper, Peter W; Flewelling, Heather; Hodapp, Klaus; Kaiser, Nicholas; Kudritzki, Rolf Peter; Magnier, Eugene; Metcalfe, Nigel; Price, Paul; Tonry, John; Wainscoat, Richard (2015). "A Three-Dimensional Map of Milky Way Dust". The Astrophysical Journal. 810: 25. arXiv:1507.01005. Bibcode:2015ApJ...810...25G. doi:10.1088/0004-637X/810/1/25.
- 1 2 "Great Rift: Dark area in the Milky Way". EarthSky Communications. 2010. Retrieved 2010-06-15.
- ↑ Pitts, Sam. "NGC 891 Edge on Galaxy (HV19)". Sams Astro. Retrieved 2009-04-25.
References
- "The Great Rift". Encyclopædia Britannica Online. 2009. Retrieved 2009-04-25.
- "Great Rift". Sci-Tech Dictionary:. Retrieved 2009-04-25.
- Kaler, Jim. "The Milky Way - From STARS". University of Illinois at Urbana-Champaign. Department of Astronomy. pp. Maps 2 and 5. Retrieved 2009-04-25.
- Dark River, Wide Field by Rogelio Bernal Andreo, at APOD