The Universe within 100 million Light Years

The Universe within 100 million Light Years
The Virgo Supercluster

Number of galaxy groups within 100 million light years = 200

Number of large galaxies within 100 million light years = 2500

Number of dwarf galaxies within 100 million light years = 50 000

Number of stars within 100 million light years = 200 trillion

About the Map

Our galaxy is just one of thousands that lie within 100 million light years. The above map shows how galaxies tend to cluster into groups, the largest nearby cluster is the Virgo cluster a concentration of several hundred galaxies which dominates the galaxy groups around it. Collectively, all of these groups of galaxies are known as the Virgo Supercluster. The second richest cluster in this volume of space is the Fornax Cluster, but it is not nearly as rich as the Virgo cluster. Only bright galaxies are depicted on the map, our galaxy is the dot in the very centre.

Additional Maps
	A Map of the Nearest Groups of Galaxies Our Local Group of galaxies is surrounded by five other galaxy groups. They are shown here on this map that shows the distribution of galaxies within 20 million light years.
	The Universe within 200 million ly The Virgo supercluster is near two other superclusters. This map shows the major groups and clusters that surround the Virgo supercluster.

Data and Catalogs
	A list of Nearby Galaxy Groups The vast majority of galaxies congregate into clusters ranging from ten to one thousand members. This is a list of most of the major galaxy groups within 100 million light years.
	The 200 Brightest Galaxies There are lots of galaxies which can be viewed with a small telscope. This is a list of the 200 brightest galaxies listed together with the best distance estimates available for these galaxies.

Information on some Nearby Galaxy Groups

Sculptor Group
	The Sculptor group is the nearest group of galaxies to the Local Group and is dominated by five galaxies, four spiral - NGC 247, 253, 300 and 7793 and one irregular - NGC 55. The nearest of these is NGC 55 which lies on the border of the Sculptor group and our Local group.
Maffei Group
	In 1968, the Italian astronomer Paolo Maffei discovered two galaxies hidden behind the plane of our galaxy and thus heavily obscured by interstellar matter. These two galaxies are known as Maffei 1 and Maffei 2. Together with the galaxy IC342, and the extremely obscured galaxy Dwingeloo 1 they make up the dominant members of another nearby group. Maffei 1 is the nearest large elliptical galaxy to us. Although observation of the group is difficult, there are now over 20 member galaxies known, most of which are dwarfs.
M81 Group
	This is a prominent nearby group in Ursa Major and is centred around the famous M81/M82 pair of galaxies together with the fairly bright NGC 2403 galaxy. M82 is a famous starburst galaxy, the galaxy has had a close encounter with its larger neighbour M81 in the past few million years, and the near-miss has generated a large wave of star formation within the galaxy.
Canes I Group
	Another nearby group centred around NGC 4214, 4244 and 4395. The spiral galaxy M94 also probably lies at the back of this group. This group is notable for containing a large number of medium-sized dwarf galaxies.
NGC 5128 Group
	This is a neighbouring group of galaxies in Centaurus and is dominated by the two spiral galaxies M83 and NGC 4945 and the large lenticular galaxy NGC 5128. NGC 5128 is one of the brightest nearby galaxies and it is a powerful source of radio waves (radio astronomers call the galaxy Centaurus A). The galaxy also seems to have merged with a large spiral galaxy within the past few hundred million years.
M101 Group
	This group is centred around the famous M101 galaxy which is one of the nearest giant spiral galaxies - it has a diameter of 200 thousand light years. Near this group lies the M51 (NGC 5194) group, and these two groups are often included together in lists as one large group.
Canes II Group
	Another large collection of spiral galaxies in Canes Venatici, the dominant members are probably M106, NGC 4096 and NGC 4490, but there are many other galaxy groups in this area of the sky and this whole region is known as the Canes Cloud.
Leo I Group
	This is a large and prominant group of spiral galaxies in Leo consisting of two main subgroups, one centred around M65, M66 and NGC 3628, and the other centred around M95, M96, M105 and NGC 3384.
Virgo Cluster
	This is the most famous cluster of galaxies. It is much larger than any other group within 100 million light years. There are about 150 large galaxies in this cluster and at least a thousand known dwarf galaxies. This cluster completely dominates our tiny corner of the Universe, and even our Local Group of galaxies is being gravitationally pulled by this cluster. At the core of the Virgo cluster lie the three large elliptical galaxies M84, M86 and M87. These galaxies probably formed from the merger of many smaller galaxies and are much more massive than our own galaxy.
Ursa Major Groups
	This is a large spur of spiral galaxies on one side of the Virgo cluster stretching across 20 million light years of space. There are probably two main groups here - Ursa Major North (around NGC 3631, 3953, and M109) and Ursa Major South (around NGC 3726, 3938 and 4051).
Virgo II Groups
	The Virgo II groups are a long filament of galaxies extending southwards from the groups of galaxies at the southern edge of the Virgo cluster.
Fornax Cluster
	The second richest cluster within 100 million light years is the Fornax cluster although it is much smaller than the Virgo cluster. There are actually two neighbouring clusters here called the Fornax I cluster and the Fornax II or Eridanus group. These two clusters contain about 50 large galaxies each. The groups of galaxies around the Fornax cluster are sometimes called the Fornax supercluster or Southern supercluster.
Leo II Groups
	The Leo II Groups are a large collection of galaxy groups clustered about 30 million light years to one side of the Virgo cluster.
Virgo III Groups
	These galaxy groups stretching away from the Virgo cluster are called the Virgo III cloud. The gravitational pull of the Virgo cluster is probably why this collection of groups has been stretched into a long filament.

Sculptor Group

The Sculptor group is the nearest group of galaxies to the Local Group and is dominated by five galaxies, four spiral - NGC 247, 253, 300 and 7793 and one irregular - NGC 55. The nearest of these is NGC 55 which lies on the border of the Sculptor group and our Local group.

Maffei Group

In 1968, the Italian astronomer Paolo Maffei discovered two galaxies hidden behind the plane of our galaxy and thus heavily obscured by interstellar matter. These two galaxies are known as Maffei 1 and Maffei 2. Together with the galaxy IC342, and the extremely obscured galaxy Dwingeloo 1 they make up the dominant members of another nearby group. Maffei 1 is the nearest large elliptical galaxy to us. Although observation of the group is difficult, there are now over 20 member galaxies known, most of which are dwarfs.

M81 Group

This is a prominent nearby group in Ursa Major and is centred around the famous M81/M82 pair of galaxies together with the fairly bright NGC 2403 galaxy. M82 is a famous starburst galaxy, the galaxy has had a close encounter with its larger neighbour M81 in the past few million years, and the near-miss has generated a large wave of star formation within the galaxy.

Canes I Group

Another nearby group centred around NGC 4214, 4244 and 4395. The spiral galaxy M94 also probably lies at the back of this group. This group is notable for containing a large number of medium-sized dwarf galaxies.

NGC 5128 Group

This is a neighbouring group of galaxies in Centaurus and is dominated by the two spiral galaxies M83 and NGC 4945 and the large lenticular galaxy NGC 5128. NGC 5128 is one of the brightest nearby galaxies and it is a powerful source of radio waves (radio astronomers call the galaxy Centaurus A). The galaxy also seems to have merged with a large spiral galaxy within the past few hundred million years.

M101 Group

This group is centred around the famous M101 galaxy which is one of the nearest giant spiral galaxies - it has a diameter of 200 thousand light years. Near this group lies the M51 (NGC 5194) group, and these two groups are often included together in lists as one large group.

Canes II Group

Another large collection of spiral galaxies in Canes Venatici, the dominant members are probably M106, NGC 4096 and NGC 4490, but there are many other galaxy groups in this area of the sky and this whole region is known as the Canes Cloud.

Leo I Group

This is a large and prominant group of spiral galaxies in Leo consisting of two main subgroups, one centred around M65, M66 and NGC 3628, and the other centred around M95, M96, M105 and NGC 3384.

Virgo Cluster

This is the most famous cluster of galaxies. It is much larger than any other group within 100 million light years. There are about 150 large galaxies in this cluster and at least a thousand known dwarf galaxies. This cluster completely dominates our tiny corner of the Universe, and even our Local Group of galaxies is being gravitationally pulled by this cluster. At the core of the Virgo cluster lie the three large elliptical galaxies M84, M86 and M87. These galaxies probably formed from the merger of many smaller galaxies and are much more massive than our own galaxy.

Ursa Major Groups

This is a large spur of spiral galaxies on one side of the Virgo cluster stretching across 20 million light years of space. There are probably two main groups here - Ursa Major North (around NGC 3631, 3953, and M109) and Ursa Major South (around NGC 3726, 3938 and 4051).

Virgo II Groups

The Virgo II groups are a long filament of galaxies extending southwards from the groups of galaxies at the southern edge of the Virgo cluster.

Fornax Cluster

The second richest cluster within 100 million light years is the Fornax cluster although it is much smaller than the Virgo cluster. There are actually two neighbouring clusters here called the Fornax I cluster and the Fornax II or Eridanus group. These two clusters contain about 50 large galaxies each. The groups of galaxies around the Fornax cluster are sometimes called the Fornax supercluster or Southern supercluster.

Leo II Groups

The Leo II Groups are a large collection of galaxy groups clustered about 30 million light years to one side of the Virgo cluster.

Virgo III Groups

These galaxy groups stretching away from the Virgo cluster are called the Virgo III cloud. The gravitational pull of the Virgo cluster is probably why this collection of groups has been stretched into a long filament.

This is a map of the Virgo cluster - the nearest large cluster of galaxies. The map shows the positions of 500 of the brightest galaxies in and around this cluster. At the centre of the cluster are several massive elliptical galaxies. It is impossible to get a good photograph of the entire cluster because the galaxies are faint objects scattered across 15 degrees of the sky, and a large angle photograph would be swamped by thousands of foreground stars in our own galaxy. The 26 brightest galaxies are labeled.

The Universe within 100 million Light YearsThe Virgo Supercluster

About the Map

Information on some Nearby Galaxy Groups

The Universe within 100 million Light Years
The Virgo Supercluster