Sag A*
(Sagittarius A*, Sgr A*)
(SMBH at the center of Milky Way)
Sag A* (more officially, Sgr A*) is the
supermassive black hole (SMBH) at the center of the Milky Way.
It is not active now, i.e., appreciable accretion is not
taking place. Its mass is 4.3 million MSun.
Reflections on molecular clouds in the region (acting as
reflection nebulae) are believed to have revealed some of
the SMBH's past activity.
It is a radio source (RS) discovered in 1974 within an area of the sky
already noted for its radio signal from the beginning of
radio astronomy. It was theorized to be a black hole for
some years, followed by considerable confirmation in 2002 with the
observation of orbits of stars in its vicinity (e.g., S2),
orbiting something unseen that was clearly the mass of an SMBH.
The Event Horizon Telescope (EHT), which was developed to resolve its event horizon
using millimeter astronomy, released its first image in 2022
after years of effort.
(black hole)
Further reading:
https://en.wikipedia.org/wiki/Sagittarius_A%2A
https://en.wikipedia.org/wiki/Event_Horizon_Telescope#Sagittarius_A%2A
https://simbad.cds.unistra.fr/simbad/sim-id?Ident=NAME+Sgr+A%2a
https://ui.adsabs.harvard.edu/abs/1954AJ.....59..439K/abstract
https://ui.adsabs.harvard.edu/abs/1982ApJ...262..110B/abstract
https://ui.adsabs.harvard.edu/abs/1996GCNew...2....3P/abstract
https://www.nasa.gov/image-article/supermassive-black-hole-sagittarius/
Redshift | Parsecs /Distance | Lightyears /Lookback Years | | |
~0 | 8.28kpc | 27.0kly | | Sag A* |
|
Coordinates: | Sag A* J174540.0409-290028.118 |
|
Referenced by pages:
Event Horizon Telescope (EHT)
Fermi bubbles
galactic bulge
galactic center
S-Star Cluster
Sgr B2
SGR J1745-2900
stellar nucleus
supermassive black hole (SMBH)
Index