Astronomical object
From ArticleWorld
An astronomical object is any object existing in space that is of note in the field of astronomy. This includes objects found within our solar system as well as those found outside of it. Astronomical objects can vary from the smallest asteroids to the largest galaxy superclusters.
Within the solar system
The most well-known astronomical objects within our solar system are the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. Some also consider the recently-discovered distant planetoid Xena to be a planet.
The sun itself is an astronomical object, as are the moons and satellites of the planets orbiting around it. Asteroids, meteors, comets, and the objects in the distant Oort cloud all qualify as solar system astronomical objects.
Outside of the solar system
Bodies outside of the solar system are divided into simple, extended and compound objects. Simple objects are single bodies in space, and extended objects are generally diffuse, amorphous entities such as nebulae and universal energies like cosmic background radiation. Compound objects are generally combinations or groupings of simple objects, though they can include nebulae where large clusters of stars are contained. A very common simple astronomical object in space is the star. Common compound extrasolar astronomical objects include star clusters and galaxies.
The universe is host to millions of common as well as exotic objects. Some of the more interesting objects include:
- Extrasolar planets
- Interstellar planets
- Black holes
- Pulsars
- Quasars
- Dark matter
- Supernovae
- Gamma ray bursters
Some exotic astronomical objects, such as gamma ray bursters, white holes, wormholes and WIMPs, are hypothetical, and have not been proven to exist.