Search results
Results from the WOW.Com Content Network
The Galactic Center is the barycenter of the Milky Way and a corresponding point on the rotational axis of the galaxy. [ 1 ] [ 2 ] Its central massive object is a supermassive black hole of about 4 million solar masses , which is called Sagittarius A* , [ 3 ] [ 4 ] [ 5 ] a compact radio source which is almost exactly at the galactic rotational ...
Sagittarius A*, abbreviated as Sgr A* (/ ˈ s æ dʒ ˈ eɪ s t ɑːr / SADGE-AY-star [3]), is the supermassive black hole [4] [5] [6] at the Galactic Center of the Milky Way.Viewed from Earth, it is located near the border of the constellations Sagittarius and Scorpius, about 5.6° south of the ecliptic, [7] visually close to the Butterfly Cluster (M6) and Lambda Scorpii.
In April 1933, Karl Jansky, considered one of the fathers of radio astronomy, discovered that a radio signal was coming from a location in the direction of the constellation of Sagittarius, towards the center of the Milky Way. [2] His observations did not extend quite as far south as we now know to be the Galactic Center. [3]
The Sagittarius A* cluster is the cluster of stars in close orbit around Sagittarius A*, the supermassive black hole at the center of the Milky Way (in the Galactic Center). The individual stars are often listed as " S-stars ", but their names and IDs are not formalized, and stars can have different numbers in different catalogues .
Tracing galactic evolution. The Milky Way started out small and grew in size as it merged with other galaxies, gaining stars as well as hydrogen to form more stars. Each galaxy has hydrogen gas ...
Surrounding the galactic disk is a spherical galactic halo of stars and globular clusters that extends farther outward, but is limited in size by the orbits of two Milky Way satellites, the Large and Small Magellanic Clouds, whose closest approach to the Galactic Center is about 180,000 ly (55 kpc). [159]
Given that the Milky Way is between 10° and 20° wide, it takes between 700 and 1,400 years for the Sun's December solstice position to precess through it. [84] In 2012 it was about halfway through the Milky Way, crossing the galactic equator. [85] In 2012, the Sun's December solstice fell on 21 December. [86]
The galactic year, also known as a cosmic year, is the duration of time required for the Sun to orbit once around the center of the Milky Way Galaxy. [1] One galactic year is approximately 225 million Earth years . [ 2 ]