NGC 4945
Encyclopedia
NGC 4945 is a spiral galaxy
in the constellation
Centaurus
. It is thought to be quite similar to the Milky Way Galaxy, but X-ray observations show that NGC 4945 has an unusual, energetic, Seyfert
2 nucleus that might house a large black hole
. It was discovered by James Dunlop
in 1826.
.
Spiral galaxy
A spiral galaxy is a certain kind of galaxy originally described by Edwin Hubble in his 1936 work The Realm of the Nebulae and, as such, forms part of the Hubble sequence. Spiral galaxies consist of a flat, rotating disk containing stars, gas and dust, and a central concentration of stars known as...
in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
Centaurus
Centaurus
Centaurus is a bright constellation in the southern sky. One of the largest constellations, Centaurus was included among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations.-Stars:...
. It is thought to be quite similar to the Milky Way Galaxy, but X-ray observations show that NGC 4945 has an unusual, energetic, Seyfert
Seyfert galaxy
Seyfert galaxies are a class of galaxies with nuclei that produce spectral line emission from highly ionized gas, named after Carl Keenan Seyfert, the astronomer who first identified the class in 1943...
2 nucleus that might house a large black hole
Black hole
A black hole is a region of spacetime from which nothing, not even light, can escape. The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole there is a mathematically defined surface called an event horizon that...
. It was discovered by James Dunlop
James Dunlop
James Dunlop was an astronomer's assistant who was hired by Sir Thomas Brisbane to work at his private observatory, once located at Paramatta , New South Wales, about twenty-three kilometres west of Sydney, Australia during the 1820s and 1830s...
in 1826.
Galaxy group information
NGC 4945 one of the brightest galaxies within the Centaurus A/M83 Group, a large, nearby group of galaxies. The galaxy is the second brightest galaxy within the subgroup centered on Centaurus ACentaurus A
Centaurus A is a prominent galaxy in the constellation of Centaurus. There is considerable debate in the literature regarding the galaxy's fundamental properties such as its Hubble type and distance...
.