NGC 4013 is an edge-on

barred spiral galaxy A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure composed of stars. Bars are found in about two thirds of all spiral galaxies, and generally affect both the motions of stars and interstellar gas within spiral galaxies ...

about 55 million

light-years A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

away in the constellation

Ursa Major Ursa Major (; also known as the Great Bear) is a constellation in the northern sky, whose associated mythology likely dates back into prehistory. Its Latin name means "greater (or larger) bear," referring to and contrasting it with nearby Ursa ...

. The disk of NGC 4013 shows a distinct "peanut"-shaped bulge in long exposure photographs that N-body computer simulations suggest is consistent with a stellar bar seen perpendicular to the line of sight.

A recent

deep color Color depth or colour depth (see spelling differences), also known as bit depth, is either the number of bits used to indicate the color of a single pixel, or the number of bits used for each color component of a single pixel. When referring to ...

image of NGC 4013 revealed a looping tidal stream of stars extending over 80 thousand light-years from the

Galactic Center The Galactic Center or Galactic Centre is the rotational center, the barycenter, of the Milky Way galaxy. Its central massive object is a supermassive black hole of about 4 million solar masses, which is called Sagittarius A*, a compact ra ...

. This structure is thought to be the remnants of a smaller galaxy that was torn apart by

tidal forces The tidal force is a gravitational effect that stretches a body along the line towards the center of mass of another body due to a gradient (difference in strength) in gravitational field from the other body; it is responsible for diverse phenomen ...

as it collided with NGC 4013. Supernova SN 1989Z was discovered on December 30, 1989 at apparent magnitude 12. NGC 4013 is a member of the Ursa Major Cluster.

References

External links

*
The Discovery of a Giant Stellar Tidal Stream Around NGC4013

HubbleSite NewsCenter: A Galaxy on the Edge
* Barred spiral galaxies Ursa Major Ursa Major Cluster 4013 06963 37691 Astronomical objects discovered in 1788 {{Spiral-galaxy-stub

See also

References

External links