NGC 4565
Encyclopedia
NGC 4565 is an edge-on spiral galaxy
about 30 to 50 million light-year
s away in the constellation
Coma Berenices
.
The 10th magnitude galaxy sits perpendicular to our own Milky Way galaxy and is almost directly above the North Galactic Pole (in the same way Polaris is located above the Earth's North Pole).
It is known as the Needle Galaxy for its narrow profile. First spotted in 1785 by Sir William Herschel
(1738–1822), this is one of the most famous examples of an edge-on spiral galaxy. "Visible through a small telescope, some sky enthusiasts consider NGC 4565 to be a prominent celestial masterpiece Messier missed."
Much speculation exists in the literature as to the nature of the central bulge. In the absence of clear-cut dynamical data on the motions of stars in the bulge, the photometric data alone cannot adjudge among various options put forth. However, its exponential shape suggests that it is a barred spiral galaxy
.
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...
about 30 to 50 million light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s away 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....
Coma Berenices
Coma Berenices
Coma Berenices is a traditional asterism that has since been defined as one of the 88 modern constellations. It is located near Leo, to which it formerly belonged, and accommodates the North Galactic Pole...
.
The 10th magnitude galaxy sits perpendicular to our own Milky Way galaxy and is almost directly above the North Galactic Pole (in the same way Polaris is located above the Earth's North Pole).
It is known as the Needle Galaxy for its narrow profile. First spotted in 1785 by Sir William Herschel
William Herschel
Sir Frederick William Herschel, KH, FRS, German: Friedrich Wilhelm Herschel was a German-born British astronomer, technical expert, and composer. Born in Hanover, Wilhelm first followed his father into the Military Band of Hanover, but emigrated to Britain at age 19...
(1738–1822), this is one of the most famous examples of an edge-on spiral galaxy. "Visible through a small telescope, some sky enthusiasts consider NGC 4565 to be a prominent celestial masterpiece Messier missed."
Much speculation exists in the literature as to the nature of the central bulge. In the absence of clear-cut dynamical data on the motions of stars in the bulge, the photometric data alone cannot adjudge among various options put forth. However, its exponential shape suggests that it is a barred spiral galaxy
Barred spiral galaxy
A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure composed of stars. Bars are found in approximately two-thirds of all spiral galaxies...
.
External links
- National Optical Astronomical Observatory – NGC 4565
- APOD (2010-03-04) – NGC 4565: Galaxy on Edge
- APOD (2009-04-28) – NGC 4565