An extrasolar planet more massive than the Earth but less massive than 10 Earth masses. The first discovered super-Earth orbits an M4 V star named GJ 876. Its estimated mass is 7.5±0.7 Earth masses an
d it has an orbital period of 1.94 days. It is close to the host star, and the surface temperature is calculated to lie between 430 and 650 K.
A spherical coordinate system in which the equator is the supergalactic plane. Supergalactic longitude, SGL, is measured counterclockwise from direction l = 137.37 deg, b = 0 deg (between 0 and 360 de
g). The zero point for supergalactic longitude is defined by the intersection of this plane with the Galactic plane. In the equatorial coordinate system (J2000) this is approximately 2.82 h, +59.5 deg. Supergalactic latitude, SGB, is measured from the supergalactic plane, positive northward and negative southward. The North Supergalactic Pole (SGB=90 deg) lies at galactic coordinates l = 47.37 deg, b = +6.32 degrees, corresponding to the equatorial coordinate system (J2000) 18.9 h, +15.7 deg.
Supergalactic coordinates are coordinates in a spherical coordinate system which was designed to have its equator aligned with the supergalactic plane, which is the (two-dimensional) plane going throu
gh the structure formed by clusters of galaxies close to the Sun. The zero point for supergalactic longitude is defined by the intersection of this plane with the galactic plane.
A system of large-scale velocity cells that does not vary significantly over the quiet solar surface or with phase of the solar cycle. The cells are presumably convective in origin with weak upward mo
tions in the center, downward motions at the borders, and horizontal motions of typically 0.3 to 0.4 km/s. Magnetic flux is more intense along the borders of the cells.
The part of an object or distributionsurrounding some central body or distribution evident in a second break inthe distribution function (e.g., a different power law). It consists of apopulation at a
higher energies than for a halo.
Ice exposed at the surface of a glacier that was formed by the freezing of melted snow after deposition; usually located below the snow line and above the equilibrium line. Although it is ice, it is p
art of the accumulation area.
Ice that forms as a result of the freezing of water-saturated snow. It commonly forms at the surface of a glacier between the equilibrium line and the firn line, and gives the glacier additional mass.
Ice accumulated on the current summer surface, during the current mass-balance year, by the refreezing there of rain or meltwater. Superimposed ice is not the same thing as internal accumulation, whic
h represents refreezing below the summer surface. Superimposed ice becomes glacier ice at the end of the mass-balance year. Superimposed ice requires special attention in conventional mass-balance programmes. In a pair of stake measurements, at the start and end of the ablation season, accumulation of superimposed ice causes a decrease of the distance from the top of the stake to the ice surface (regardless of any overlying snow). This decrease is real and not, for example, due to faulty book-keeping.
The part of the glacier where superimposed ice is exposed. The superimposed ice zone occupies the range of elevations below the snowline and above the equilibrium line. Superimposed ice may also be fo
und beneath snow of the current year at elevations above the snowline. Whether exposed or beneath the surface, it requires special attention in mass-balance measurements.
A black hole of tremendous mass, equivalent to those of millions or even billions of stars, which is believed to exist and occupy the centers of many galaxies. The supermassive black hole residing in
the center of our Milky Way Galaxy is the object Sgr A* with a mass of 4 x 10^6 solar masses within a radius of 100 astronomical units.