Quantcast

Astronomy Reference Libraries

Page 3 of about 165 Articles
The Local Group
2010-09-13 17:05:00

The Local Group, compromising more than 30 galaxies (including dwarf galaxies and the Milky Way), is a group of galaxies with a gravitational center located somewhere between the Milky Way and the Andromeda Galaxy. With a binary (dumbbell) shape and a total mass of (1.29 ± 0.14) × 1012M the Local group covers a 10 million light-year diameter. The local group is part of the Virgo...

IC 342
2010-09-13 16:59:36

The IC 342/Maffei Group (also known as the IC 342 Group or the Maffei 1 Group) is the closest group of galaxies to the Local Group. The member galaxies are both concentrated around the two brightest galaxies of IC 342 and Maffei 1. The group can therefore be described as a binary group. Along with many others the group is located in the Virgo Supercluster.

Coma Cluster
2010-09-13 16:56:08

The Coma Cluster (Abell 1656), along with the Leo Cluster, is one of two major clusters compromising the Coma Supercluster. It contains over 1000 identified galaxies. Most of the galaxies in the center of the Coma Cluster are elliptical galaxies including both dwarf and giant. However the center is dominated by NGC 4874 and NGC 4889, two giant elliptical galaxies. The brightest galaxies are...

Centaurus Cluster
2010-09-13 16:39:39

The Centaurus A/M83, divided into subgroup Cen A and M83, is a complex group of galaxies located within Hydra, Centaurus, and Virgo constellations. The Cen A Subgroup, at a distance of 11.9 Mly (3.66 Mpc), is centered around Centaurus A, a nearby radio galaxy. The M83 Subgroup, at a distance of 14.9 Mly (4.56 Mpc), is centered around the Messier 83 (M83), a face-on spiral galaxy. Due to the...

Stephans Quintet
2010-09-13 16:27:55

Stephan's Quintet in the constellation Pegasus is a visual grouping of five galaxies which four form the first compact galaxy group ever discovered. The group was discovered by Édouard Stephan in 1877 at Marseilles Observatory and is the most studied of all the compact galaxy groups. NGC 7320, which has extensive H II regions, is the brightest member of the visual grouping and is where...

Sculptor Group
2010-09-13 16:24:54

At a distance of 3.9 Mpc from the Milky Way, the Sculptor Group is one of nearest groups of galaxies to the Local Gropu. Sculptor is made up of a loose group of galaxies near the south galactic pole. The Sculptor Galaxy (NGC 253) and a few other galaxies form a gravitationally-bound core in the center of this group, however, since they are only weakly bound the group may also be described...

Roberts Quartet
2010-09-08 16:15:14

Robert's Quartet is four different galaxies in the process of colliding and merging. The galaxies reside in the Phoenix constellation approximately 160 million light-years away. Its members are NGC 87, NGC 88, NGC 89 and NGC 92, discovered by John Herschel in the 1830s. The quartet is one of the best examples of compact groups of galaxies. Since such groups contain four to eight galaxies in a...

Markarians Chain
2010-09-08 16:10:01

Markarian's Chain is a stretch of galaxies forming part of the Virgo Cluster. The galaxies get their name because when viewed from earth they form a curved line. The other part of the name comes from the Armenian astrophysicist, B. E. Markarian. Markarian discovered their common proper motion in the mid 1970s. Member galaxies include M84 (NGC 4374), M86 (NGC 4406), NGC 4477, NGC 4473, NGC 4461,...

Leo Triplet
2010-09-08 16:07:17

The Leo Triplet, consisting of the spiral galaxies M65, the M66, and the NGC 3628, is also called the M66 group. The small group of galaxies is about 35 million light-years in the constellation LEO. In close proximity is the M96 Group. It is believed that these two groups may be separate parts of a much larger group. There is also some group identification algorithms that identify the Leo...

JKCS 041
2010-09-08 16:02:39

As of 2009, JKCS 041 is a group of galaxies with the distinction of being the farthest away group from Earth ever observed. Seen at redshift 1.9, it is estimated to be 10.2 billion light years away. The cluster is located within the constellation Cetus at a photometrically determined redshift of z=1.9 at right ascension 2h 26m 44s declination -04° 41"² 37"³ (J2000.0).

Word of the Day
cacodemon
  • An evil spirit; a devil.
  • A nightmare.
  • In astrology, the twelfth house of a scheme or figure of the heavens: so called from its signifying dreadful things, such as secret enemies, great losses, imprisonment, etc.
'Cacodemon' comes from a Greek term meaning 'evil genius.'
Related