50 relations: Accretion (astrophysics), Apparent magnitude, Asterism (astronomy), Bayer designation, Billion years, Binary star, Blue straggler, Caldwell catalogue, Cambridge University Press, Cataclysmic variable star, Celestial pole, Chandra X-ray Observatory, Chromosphere, Comet, Constellation, Earth, Eclipse, Epoch (astronomy), Fermi Gamma-ray Space Telescope, Globular cluster, Hubble Space Telescope, Intermediate-mass black hole, Johann Bayer, Johann Elert Bode, List of globular clusters, Mass segregation (astronomy), Metallicity, Millisecond pulsar, Minute and second of arc, Monthly Notices of the Royal Astronomical Society, Moon, Naked eye, Neutron star, New General Catalogue, Nicolas-Louis de Lacaille, Omega Centauri, Planet, Pulsar, Ragbir Bhathal, Right ascension, Small Magellanic Cloud, Stellar population, Tucana, Urania, Uranometria, Western Sydney University, White dwarf, X-ray, X-ray binary, 1RXS.
In astrophysics, accretion is the accumulation of particles into a massive object by gravitationally attracting more matter, typically gaseous matter, in an accretion disk.
The apparent magnitude of a celestial object is a number that is a measure of its brightness as seen by an observer on Earth.
In observational astronomy, an asterism is a popular known pattern or group of stars that are recognised in the night sky.
A Bayer designation is a stellar designation in which a specific star is identified by a Greek letter, followed by the genitive form of its parent constellation's Latin name.
A billion years (109 years) is a unit of time on the petasecond scale, more precisely equal to seconds.
A binary star is a star system consisting of two stars orbiting around their common barycenter.
A blue straggler is a main-sequence star in an open or globular cluster that is more luminous and bluer than stars at the main-sequence turn-off point for the cluster.
The Caldwell Catalogue is an astronomical catalogue of 109 star clusters, nebulae, and galaxies for observation by amateur astronomers.
Cambridge University Press (CUP) is the publishing business of the University of Cambridge.
Cataclysmic variable stars (CV) are stars which irregularly increase in brightness by a large factor, then drop back down to a quiescent state.
The north and south celestial poles are the two imaginary points in the sky where the Earth's axis of rotation, indefinitely extended, intersects the celestial sphere.
The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space observatory launched on STS-93 by NASA on July 23, 1999.
The chromosphere (literally, "sphere of color") is the second of the three main layers in the Sun's atmosphere and is roughly 3,000 to 5,000 kilometers deep.
A comet is an icy small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process called outgassing.
A constellation is a group of stars that are considered to form imaginary outlines or meaningful patterns on the celestial sphere, typically representing animals, mythological people or gods, mythological creatures, or manufactured devices.
Earth is the third planet from the Sun and the only astronomical object known to harbor life.
An eclipse is an astronomical event that occurs when an astronomical object is temporarily obscured, either by passing into the shadow of another body or by having another body pass between it and the viewer.
In astronomy, an epoch is a moment in time used as a reference point for some time-varying astronomical quantity, such as the celestial coordinates or elliptical orbital elements of a celestial body, because these are subject to perturbations and vary with time.
The Fermi Gamma-ray Space Telescope (FGST), formerly called the Gamma-ray Large Area Space Telescope (GLAST), is a space observatory being used to perform gamma-ray astronomy observations from low Earth orbit.
A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite.
The Hubble Space Telescope (HST) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation.
An intermediate-mass black hole (IMBH) is a class of black hole with mass in the range 102-105 solar masses: significantly more than stellar black holes but less than the 105-109 solar mass supermassive black holes.
Johann Bayer (1572 – 7 March 1625) was a German lawyer and uranographer (celestial cartographer).
Johann Elert Bode (19 January 1747 – 23 November 1826) was a German astronomer known for his reformulation and popularisation of the Titius–Bode law.
This is a list of globular clusters.
In astronomy, dynamical mass segregation is the process by which heavier members of a gravitationally bound system, such as a star cluster or cluster of galaxies, tend to move toward the center, while lighter members tend to move farther away from the center.
In astronomy, metallicity is used to describe the abundance of elements present in an object that are heavier than hydrogen or helium.
A millisecond pulsar (MSP) is a pulsar with a rotational period in the range of about 1–10 milliseconds.
A minute of arc, arcminute (arcmin), arc minute, or minute arc is a unit of angular measurement equal to of one degree.
Monthly Notices of the Royal Astronomical Society (MNRAS) is a peer-reviewed scientific journal covering research in astronomy and astrophysics.
The Moon is an astronomical body that orbits planet Earth and is Earth's only permanent natural satellite.
Naked eye, also called bare eye or unaided eye, is the practice of engaging in visual perception unaided by a magnifying or light-collecting optical instrument, such as a telescope or microscope.
A neutron star is the collapsed core of a large star which before collapse had a total of between 10 and 29 solar masses.
The New General Catalogue of Nebulae and Clusters of Stars (abbreviated as NGC) is a catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888.
Abbé Nicolas-Louis de Lacaille, formerly sometimes spelled de la Caille, (15 March 1713 – 21 March 1762) was a French astronomer.
Omega Centauri (ω Cen or NGC 5139) is a globular cluster in the constellation of Centaurus that was first identified as a non-stellar object by Edmond Halley in 1677.
A planet is an astronomical body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.
A pulsar (from pulse and -ar as in quasar) is a highly magnetized rotating neutron star or white dwarf that emits a beam of electromagnetic radiation.
Ragbir Bhathal is an Australian astronomer and author, currently based at the Western Sydney University (WSU), Australia.
Right ascension (abbreviated RA; symbol) is the angular distance measured only eastward along the celestial equator from the Sun at the March equinox to the (hour circle of the) point above the earth in question.
The Small Magellanic Cloud (SMC), or Nubecula Minor, is a dwarf galaxy near the Milky Way.
During 1944, Walter Baade categorized groups of stars within the Milky Way into bluer stars associated with the spiral arms and the general position of yellow stars near the central galactic bulge or within globular star clusters.
Tucana is a constellation of stars in the southern sky, named after the toucan, a South American bird.
Urania (Οὐρανία, Ourania; meaning "heavenly" or "of heaven") was, in Greek mythology, the muse of astronomy.
Uranometria is the short title of a star atlas produced by Johann Bayer.
Western Sydney University, formerly the University of Western Sydney, is an Australian multi-campus university in the Greater Western region of Sydney.
A white dwarf, also called a degenerate dwarf, is a stellar core remnant composed mostly of electron-degenerate matter.
X-rays make up X-radiation, a form of electromagnetic radiation.
X-ray binaries are a class of binary stars that are luminous in X-rays.
1RXS is an acronym which is the prefix used for the First ROSAT X-ray Survey (1st ROSAT X-ray Survey).
1E 0021.8-7221, 1ES 0021-72.3, 1RXS J002404.6-720456, 2E 0021.8-7221, 2E 82, 2MASX J00240535-7204531, 47 Tuc, C 0021-723, Caldwell 106, Cl Melotte 1, GCl 1, Globular Cluster 47 Tucanae, Globular Cluster NGC 104, NGC 104, NGC104, RBS 55, Xi Tucanae, Ξ Tucanae.