Orion Glossary
Special | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | ALL
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helium burningThe process by which stars fuse three helium nuclei into one carbon nucleus via the triple alpha process. | |
hot JupiterA giant planet, with a mass close to or greater than that of Jupiter, and which orbits very close to its parent star. | |
Hubble deep fieldA project with the Hubble Space Telescope to obtain a series of very deep exposures to search for distant galaxies at high redshift. | |
Hubble’s lawThe observation that, for distant galaxies, the greater a galaxy’s distance, the greater the redshift of the radiation received from that galaxy. | |
hydrogen burningThe process by which stars on the main sequence release energy via the conversion of hydrogen into helium in their cores. | |
hydrogen shell burningThe process by which, in post-Main Sequence stars, hydrogen is converted into helium in a thin shell exterior to the core. | |
hydrostatic equilibriumIn a star, the state at which physical forces directed inwards are exactly balanced by those directed outwards. | |
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icy materialsA term used in Solar System studies for materials that comprise water and other substances that are solid only at relatively low temperatures, although they can be liquid on the surfaces or in the interiors of planets, or gaseous in the atmospheres of planets. | |
inclinationThe angle i between the orbital plane of an astronomical body and a reference plane. For a solar system body the reference plane is the ecliptic. (The inclination of the orbit of a binary star is the angle between the orbital plane and the plane of the sky, so that a face-on binary has i = 0 and an edge-on (eclipsing) system has i close to 90°). | |