Astronomical objects in the context of Comet nucleus

The Two Micron All-Sky Survey (2MASS) was an astronomical survey of the whole sky in infrared light. It took place between 1997 and 2001, in two different locations: at the U.S. Fred Lawrence Whipple Observatory on Mount Hopkins, Arizona, and at the Cerro Tololo Inter-American Observatory in Chile, each using a 1.3-meter telescope for the Northern and Southern Hemisphere, respectively. It was conducted in the short-wavelength infrared at three distinct frequency bands (J, H, and K) near 2 micrometres, from which the photometric survey with its HgCdTe detectors derives its name.

2MASS produced an astronomical catalog with over 300 million observed objects, including minor planets of the Solar System, brown dwarfs, low-mass stars, nebulae, star clusters and galaxies. In addition, 1 million objects were cataloged in the 2MASS Extended Source Catalog (2MASX). The cataloged objects are designated with a "2MASS" and "2MASX" prefix, respectively.

The worship of heavenly bodies is the veneration of stars (individually or together as the night sky), the planets, or other astronomical objects as deities, or the association of deities with heavenly bodies. In anthropological literature these systems of practice may be referred to as astral cults.

The most notable instances of this are sun gods and moon gods in polytheistic systems worldwide. Also notable are the associations of the planets with deities in Sumerian religion, and hence in Babylonian, Greek and Roman religion, viz. Mercury, Venus, Mars, Jupiter, and Saturn. Gods, goddesses, and demons may also be considered personifications of astronomical phenomena such as lunar eclipses, planetary alignments, and apparent interactions of planetary bodies with stars. The Sabians of Harran, a poorly understood pagan religion that existed in Harran during the early Islamic period (7th–10th century), were known for their astral cult.

The Messier objects are a set of 110 astronomical objects catalogued by the French astronomer Charles Messier in his Catalogue des Nébuleuses et des Amas d'Étoiles [fr] (Catalogue of Nebulae and Star Clusters). Because Messier was interested only in finding comets, he created a list of those non-comet objects that frustrated his hunt for them. This list, which Messier created in collaboration with his assistant Pierre Méchain, is now known as the Messier catalogue. The Messier catalogue is one of the most famous lists of astronomical objects, and many objects on the list are still referenced by their Messier numbers. The catalogue includes most of the astronomical deep-sky objects that can be easily observed from Earth's Northern Hemisphere; many Messier objects are popular targets for amateur astronomers.

A preliminary version of the catalogue first appeared in 1774 in the Memoirs of the French Academy of Sciences for the year 1771. The first version of Messier's catalogue contained 45 objects, which were not numbered. Eighteen of the objects were discovered by Messier; the rest had been previously observed by other astronomers. By 1780 the catalogue had increased to 70 objects. The final version of the catalogue containing 103 objects was published in 1781 in the Connaissance des Temps for the year 1784. However, due to what was thought for a long time to be the incorrect addition of Messier 102, the total number remained 102. Other astronomers, using side notes in Messier's texts, eventually expanded the list to 110 objects.

The Messier objects are a set of 110 astronomical objects catalogued by the French astronomer Charles Messier in his Catalogue des Nébuleuses et des Amas d'Étoiles (fr) (Catalogue of Nebulae and Star Clusters). Because Messier was interested only in finding comets, he created a list of those non-comet objects that frustrated his hunt for them. This list, which Messier created in collaboration with his assistant Pierre Méchain, is now known as the Messier catalogue. The Messier catalogue is one of the most famous lists of astronomical objects, and many objects on the list are still referenced by their Messier numbers. The catalogue includes most of the astronomical deep-sky objects that can be easily observed from Earth's Northern Hemisphere; many Messier objects are popular targets for amateur astronomers.

A preliminary version of the catalogue first appeared in 1774 in the Memoirs of the French Academy of Sciences for the year 1771. The first version of Messier's catalogue contained 45 objects, which were not numbered. Eighteen of the objects were discovered by Messier; the rest had been previously observed by other astronomers. By 1780 the catalogue had increased to 70 objects. The final version of the catalogue containing 103 objects was published in 1781 in the Connaissance des Temps for the year 1784. However, due to what was thought for a long time to be the incorrect addition of Messier 102, the total number remained 102. Other astronomers, using side notes in Messier's texts, eventually expanded the list to 110 objects.

The following are lists of stars. Stars are astronomical objects that spend some portion of their existence generating energy through thermonuclear fusion.

Astrophysical X-ray sources are astronomical objects with physical properties which result in the emission of X-rays.

Several types of astrophysical objects emit X-rays. They include galaxy clusters, black holes in active galactic nuclei (AGN), galactic objects such as supernova remnants, stars, and binary stars containing a white dwarf (cataclysmic variable stars and super soft X-ray sources), neutron star or black hole (X-ray binaries). Some Solar System bodies emit X-rays, the most notable being the Moon, although most of the X-ray brightness of the Moon arises from reflected solar X-rays.