Sagittarius A*
Sagittarius A* (Sgr A*) is a bright astronomical radio source at the center of the Milky Way. It is in the direction of the constellations Sagittarius and Scorpius.
| Saggitarius A* | |
|---|---|
 Saggitarius A* image by Chandra X-Ray Observatory | |
| Observation data | |
| Type | Radio source |
| Right ascension | 17h 45m 40.05s |
| Declination | ±-29° 00′ 27.9″ |
| Distance | 25900±1400 light years |
| Constellation | Saggitarius |
| Physical characteristics | |
| Notable features | Radio source in the center of the Milky Way |
| Other designations | Sgr A* |
| See also: Diffuse nebula, Lists of nebulae | |
The radio source is part of a larger astronomical feature known as Sagittarius A. Sagittarius A* is thought to be a supermassive black hole,[1][2][3] like those that are at the centers of most spiral and elliptical galaxies. Observations of the star S2 in orbit around Sagittarius A* were used to show the presence of the Milky Way's central supermassive black hole. This led to the conclusion that Sagittarius A* is the site of that black hole.[4][5] Another star, S8, is orbiting Sagittarius A* along with many other stars. A star known as S14 has an extremely elliptical orbit[6]and a star named S4716 has an orbital period of only 4 years.[7]
Sagittarius A* Media
A view of the Milky Way supermassive black hole Sagittarius A* in polarised light (eso2406a)
Chandra X-ray Observatory image of Sgr A*.
Sagittarius A* in the constellation of Sagittarius. The black hole is marked with a red circle within the constellation of Sagittarius (The Archer). This map shows most of the stars visible to the unaided eye under good conditions.
The diameter of Sagittarius A* is smaller than the orbit of Mercury.
Dusty cloud G2 passes the supermassive black hole at the center of the Milky Way. Composition of images taken at different times to show motion; colored blue when approaching the viewer, red when receding; time is left to right. Red cross marks the black hole.
NuSTAR has captured these first, focused views of the supermassive black hole at the heart of the Milky Way in high-energy X-rays.
Magnetar found very close to the supermassive black hole, Sagittarius A*, at the center of the Milky Way galaxy
Inferred orbits of six stars around supermassive black hole candidate Sagittarius A* at the Milky Way's center
Stars moving around Sagittarius A*, 20-year timelapse, ending in 2018
Stars moving around Sagittarius A* as seen in 2021
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Related pages
References
- ↑ Reynolds 2008[broken anchor]
- ↑ Overbye, Dennis (8 June 2015). "Black Hole Hunters". NASA. https://www.nytimes.com/2015/06/09/science/black-hole-event-horizon-telescope.html. Retrieved 8 June 2015.
- ↑ Overbye, Dennis; Corum, Jonathan; Drakeford, Jason (8 June 2015). "Video: Peering Into a Black Hole". New York Times. . https://www.nytimes.com/video/science/100000003725182/peering-into-a-black-hole.html. Retrieved 9 June 2015.
- ↑ Henderson, Mark (December 9, 2008). Astronomers confirm black hole at the heart of the Milky Way. Times Online. http://www.timesonline.co.uk/tol/news/uk/science/article5316001.ece. Retrieved 2009-05-17.
- ↑ Reynolds C. 2008. Astrophysics: bringing black holes into focus. Nature 455 (7209): 39–40. Bibcode:2008Natur.455...39R. doi:10.1038/455039a. PMID 18769426.
- ↑ "Orbital parameters of stars orbiting Sagittarius A*". Physics Forums: Science Discussion, Homework Help, Articles. 2016-03-02. Retrieved 2024-07-28.
- ↑ Sabha, N.; Eckart, A.; Merritt, D.; Zamaninasab, M.; Witzel, G.; García-Marín, M.; Jalali, B.; Valencia-S, M.; Yazici, S.; Buchholz, R.; Shahzamanian, B. (2012-09-01). "The S-star cluster at the center of the Milky Way - On the nature of diffuse NIR emission in the inner tenth of a parsec". Astronomy & Astrophysics. 545: A70. doi:10.1051/0004-6361/201219203. ISSN 0004-6361.
Other websites
Media related to Sagittarius A* at Wikimedia Commons