Galaxies Galaxies The dwarf galaxy problem is one that arises from numerical cosmological simulations that predict the evolution of the distribution of matter in the universe. Dark matter seems to cluster hierarchically and in ever increasing number counts for smaller and smaller sized halos. However, while there seems to be enough observed normal-sized galaxies to account for this distribution, the number of dwarf galaxies is orders of magnitude lower than expected from simulation. ...more on Wikipedia about "Dwarf galaxy problem"
Extragalactic astronomy is the branch of astronomy concerned with objects outside our own Milky Way Galaxy (the study of all astronomical objects which are not covered by galactic astronomy). ...more on Wikipedia about "Extragalactic astronomy"
Galactic astronomy is the study of our own Milky Way galaxy and all its contents. This is in contrast to extragalactic astronomy, which is the study of everything outside our galaxy, including all other galaxies. ...more on Wikipedia about "Galactic astronomy"
The galactic corona (not to be confused with the sun's corona), also called the dark matter halo, is a region of space surrounding the galactic halo of spiral galaxies, including the Milky Way Galaxy that consist mostly of dark matter. ...more on Wikipedia about "Galactic corona"
The galactic halo is a region of space surrounding spiral galaxies, including our galaxy, the Milky Way. The galactic halo is believed to consist largely of stars, gas and dark matter. In an elliptical galaxy, there is no sharp transition between the body of the galaxy and the halo. ...more on Wikipedia about "Galactic halo"
A galaxy is a huge gravitationally bound system of stars, interstellar gas and dust, plasma, and (possibly) unseen dark matter. Typical galaxies contain 10 million to one trillion (107 to 1012) stars, all orbiting a common center of gravity. In addition to single stars and a tenuous interstellar medium, most galaxies contain a large number of multiple star systems and star clusters as well as various types of nebulae. Most galaxies are several thousand to several hundred thousand light years in diameter and are usually separated from one another by distances on the order of millions of light years. ...more on Wikipedia about "Galaxy"
Astronomers classify galaxies based on their overall shape ( elliptical, spiral or barred spiral) and further by the specific properties of the individual galaxy (for example degree of ellipse, number of spirals or definition of bar). The system of galaxy classification is called the Hubble "tuning fork" diagram, and is the Hubble sequence. ...more on Wikipedia about "Galaxy classification"
In astrophysics, the questions of galaxy formation and evolution are: ...more on Wikipedia about "Galaxy formation and evolution"
The Hubble sequence is a classification of galaxy types developed by Edwin Hubble in 1936. It is also called the tuning-fork diagram as a result of the shape of its graphical representation. Galaxy types are divided as follows: ...more on Wikipedia about "Hubble sequence"
Interacting galaxies (Colliding galaxies) is the result of gravity of two close galaxies. ...more on Wikipedia about "Interacting galaxy"
== List of galaxies: == ...more on Wikipedia about "List of galaxies"
A peculiar galaxy is a galaxy which is unusual in its size, shape, or composition. Peculiar galaxies come about as a result of interactions between galaxies, and they may contain atypical amounts of dust or gas, may have higher or lower surface brightness than a typical galaxy, or may have features such as nuclear jets. They can be highly irregular in shape due to the immense gravitational forces which act on them during encounters with other galaxies. Peculiar galaxies are designated by "p" or "pec" in catalogs such as the Halton Arp catalog. ...more on Wikipedia about "Peculiar galaxy"
A satellite galaxy orbits a larger galaxy, due to gravitational attraction. Though a galaxy is made of a large number of objects (such as stars, planets, and nebulae) which are not connected to each other, it has a center of mass, which represents a weighted average (by mass) of the positions of each component object. This is similar to how an everyday object has a center of mass which is the weighted average of the positions of all its component atoms. ...more on Wikipedia about "Satellite galaxy"
Spiral nebula is an old term for a spiral galaxy. Until the early 20th century, astronomers thought that objects like the Whirlpool Galaxy were just one more form of nebula that were within our galaxy, the Milky Way. The term fell into disuse as astronomers grew to understand that the "spiral nebulae" were really whole galaxies of their own far outside of the Milky Way. ...more on Wikipedia about "Spiral nebula" Please inform your friends about http://www.shortopedia.com
A supermassive black hole is a black hole with a mass in the range of millions or billions of solar masses. It is currently thought that most if not all galaxies, including the Milky Way, contain a supermassive black hole at their galactic centers. ...more on Wikipedia about "Supermassive black hole"
This article is licensed under the GNU Free Documentation License.
It uses material from the Wikipedia . Direct links to the original articles are in the text.
If you use exact copy or modified of this article you should preserve above paragraph and put also : It uses material from
the Shortopedia article about "Galaxies".
| MAIN PAGE | MAIN INDEX | CONTACT US |