For example, the giant elliptical galaxy M87 has an absolute magnitude of − 22 ( i. e. as bright as about 60, 000 stars of magnitude − 10 ).

It is classified as being between an elliptical and a spiral galaxy because it has faint arms and a large central bulge.

This has prompted suspicion that Omega Centauri was the core of a dwarf galaxy that had been absorbed by the Milky Way.

It has a central core made of older stars that resembles an elliptical galaxy, and an outer ring of young stars that orbits around the core.

In particular, these foregrounds are dominated by galactic emissions such as free-free, synchrotron, and dust that emit in the microwave band ; in practice, the galaxy has to be removed resulting in a CMB map that is not a full-sky map.

Dark matter plays a central role in state-of-the-art modeling of structure formation and galaxy evolution, and has measurable effects on the anisotropies observed in the cosmic microwave background.

Sir Harry Kroto, who shared the 1996 Nobel Prize in Chemistry for the discovery of buckyballs commented: " This most exciting breakthrough provides convincing evidence that the buckyball has, as I long suspected, existed since time immemorial in the dark recesses of our galaxy.

Since there are many stars older than the Sun, or since intelligent life might have evolved earlier elsewhere, the question then becomes why the galaxy has not been colonized already.

It has also been suggested that the dark matter halo can pull the galaxy, thus stopping disk contraction.

Our own galaxy ( the Milky Way ) has a tiny satellite galaxy ( the Sagittarius Dwarf Elliptical Galaxy ) which is currently gradually being ripped up and " eaten " by the Milky Way.

A common form is the elliptical galaxy, which has an ellipse-shaped light profile.

An Sa galaxy has tightly wound, poorly defined arms and possesses a relatively large core region.

At the other extreme, an Sc galaxy has open, well-defined arms and a small core region.

A galaxy with poorly defined arms is sometimes referred to as a flocculent spiral galaxy ; in contrast to the grand design spiral galaxy that has prominent and well-defined spiral arms.

A lenticular galaxy is an intermediate form that has properties of both elliptical and spiral galaxies.

An Irr-I galaxy has some structure but does not align cleanly with the Hubble classification scheme.

Many dwarf galaxies may orbit a single larger galaxy ; the Milky Way has at least a dozen such satellites, with an estimated 300 – 500 yet to be discovered.

A study of 27 Milky Way neighbors found that in all dwarf galaxies, the central mass is approximately 10 million solar masses, regardless of whether the galaxy has thousands or millions of stars.

Messier 82 | M82, the archetype starburst galaxy, has experienced a 10-fold increase in star formation rate as compared to a " normal " galaxy.

Evidence for the early appearance of galaxies was found in 2006, when it was discovered that the galaxy IOK-1 has an unusually high redshift of 6. 96, corresponding to just 750 million years after the Big Bang and making it the most distant and primordial galaxy yet seen.

Given the absolute magnitude, for objects within our galaxy you can also calculate the apparent magnitude from any distance ( in parsecs ):

The constellation also harbors the wide spiral galaxy NGC 6907.

About 50 million light-years from Earth, M77 is also a Seyfert galaxy and thus a bright object in the radio spectrum.

M94, also classified as NGC 4736, is a face-on spiral galaxy 15 million light-years from Earth.

He also discovered hundreds of variable stars, as well as star clusters, galaxy clusters, and a galaxy supercluster.

Like NGC 1097, it is also a Seyfert galaxy.

Within our own galaxy, molecular gas accounts for less than one percent of the volume of the interstellar medium ( ISM ), yet it is also the densest part of the medium comprising roughly one-half of the total gas mass interior to the Sun's galactic orbit.

Photo from Rogelio Bernal Andreo of the Rho Ophiuchi cloud complex | Rho Ophiuchi molecular cloud complex. The unusual galaxy merger remnant and starburst galaxy NGC 6240 is also in Ophiuchus.

NGC 6240 also has an unusually high rate of star formation, classifying it as a starburst galaxy.

Tidal forces are stronger nearer the centre of the galaxy, increasing the rate of disruption of clusters, and also the giant molecular clouds which cause the disruption of clusters are concentrated towards the inner regions of the galaxy, so clusters in the inner regions of the galaxy tend to get dispersed at a younger age than their counterparts in the outer regions.

According to A. Zahoor, in the 11th century, the Persian polymath scholar Abu Rayhan Biruni described the Milky Way galaxy as a multitude of fragments having the properties of nebulous stars, and also gave the latitudes of various stars during a lunar eclipse in 1019.

Open clusters become disrupted over time by the gravitational influence of giant molecular clouds as they move through the galaxy, but cluster members will continue to move in broadly the same direction through space even though they are no longer gravitationally bound ; they are then known as a stellar association, sometimes also referred to as a moving group.

It is also unknown if any other galaxy contains this kind of clusters, but it would be very unlikely that M31 is the sole galaxy with extended clusters.

The Tucana Dwarf galaxy, which was discovered in 1990, is also in Tucana.

M101, also called the Pinwheel Galaxy, is a face-on spiral galaxy located 25 million light-years from Earth.

The Standard Galactic Alphabet, also known as SGA, is the writing system used to depict Omnispeak, the alien language of choice in the galaxy in the Commander Keen fictional universe.

Card also wrote the aliens as a colonizing species which preferentially sought high-pressure deepwater worlds to build their ships as they traveled further into the galaxy ( their mothership was in orbit on the far side of the moon ).

The effect is also observed when photons from the cosmic microwave background ( CMB ) move through the hot gas surrounding a galaxy cluster.

* High velocity clouds, clouds of neutral hydrogen are " raining " down on the galaxy, and presumably have been from the beginning ( this would be the necessary source of a gas disk from which the disk stars formed ).

Every galaxy of sufficient mass in the Local Group has an associated group of globular clusters, and almost every large galaxy surveyed has been found to possess a system of globular clusters.

In fact, it has been theorized that a quasar could form as the Andromeda Galaxy collides with our own Milky Way galaxy in approximately 3 – 5 billion years.

But some stars have been observed in the M100 galaxy of the Virgo Cluster, about 100 million light years from the Earth.

Supporting the view of aggression, Seth Shostak, a senior astronomer at the SETI Institute, speculates that the finite quantity of resources in the galaxy and the " explorer " nature of any civilization would cause it to be aggressive in the same way that human explorers have been historically.

The SNO detector would have been capable of detecting a supernova within our galaxy if one had occurred while the detector was online.

Our galaxy has about 150 globular clusters, some of which may have been captured from small galaxies disrupted by the Milky Way, as seems to be the case for the globular cluster M79.

Water has been detected in interstellar clouds within our galaxy, the Milky Way.

While the LMC is often considered an irregular type galaxy ( the NASA Extragalactic Database lists the Hubble sequence type as Irr / SB ( s ) m ), the LMC contains a very prominent bar in its center, suggesting that it may have previously been a barred spiral galaxy.

Recently, the Cepheid absolute luminosity has been re-calibrated using Cepheid variables in the galaxy NGC 4258 that cover a range of metallicities.

It is the most recent supernova to have been unquestionably observed by the naked eye in our own galaxy, occurring no farther than 6 kiloparsecs or about 20, 000 light-years from Earth.

Planetary nebulae play a crucial role in the chemical evolution of the galaxy, returning material to the interstellar medium that has been enriched in heavy elements and other products of nucleosynthesis ( such as carbon, nitrogen, oxygen and calcium ).

Almost every well-studied long gamma-ray burst has been linked to a galaxy with rapid star formation, and in many cases to a core-collapse supernova as well, unambiguously associating long GRBs with the deaths of massive stars.

Since then, several dozen short gamma-ray burst afterglows have been detected and localized, several of which are associated with regions of little or no star formation, such as large elliptical galaxies and the central regions of large galaxy clusters.

All the bursts astronomers have recorded so far have come from distant galaxies and have been harmless to Earth, but if one occurred within our galaxy and were aimed straight at us, the effects could be devastating.

It is only within this more recent time that passages of the heliosphere through the spiral arms of the galaxy have been able to gain a strong and regularly modulating influence as described above.

Obi-Wan wishes to fight Sidious to avoid having to kill his best friend, but Yoda insists that Obi-Wan is not strong enough to fight the new Emperor of the galaxy, and would have to accept that the Anakin he knows no longer exists, having been " consumed by Darth Vader.

With Chandra X-ray Observatory structures like cold front, shock front, minihalo have also been found in many galaxy clusters.

Graham's concept was that a group of young rebels would rescue Avon, who had been kept cryogenically frozen by Servalan, and then roam the galaxy in a new ship named Liberator.