Search results
Results from the WOW.Com Content Network
A-type star In the Harvard spectral classification system, a class of main-sequence star having spectra dominated by Balmer absorption lines of hydrogen. Stars of spectral class A are typically blue-white or white in color, measure between 1.4 and 2.1 times the mass of the Sun, and have surface temperatures of 7,600–10,000 kelvin.
A planetary mnemonic refers to a phrase created to remember the planets and dwarf planets of the Solar System, with the order of words corresponding to increasing sidereal periods of the bodies. One simple visual mnemonic is to hold out both hands side-by-side with thumbs in the same direction (typically left-hand facing palm down, and right ...
SOHO – (telescope) SOlar and Heliospheric Observatory, a solar space telescope; SONEAR – Southern Observatory for Near Earth Asteroids Research; SOLO – Solar Orbiter; SPARTAN – (telescope) Shuttle Pointed Autonomous Research Tool for AstroNomy, an ultraviolet space telescope that can be released and retrieved by the Space Shuttle
Parts-per-million chart of the relative mass distribution of the Solar System, each cubelet denoting 2 × 10 24 kg. This article includes a list of the most massive known objects of the Solar System and partial lists of smaller objects by observed mean radius. These lists can be sorted according to an object's radius and mass and, for the most ...
List of Solar System objects most distant from the Sun; List of Solar System objects by size; Lists of geological features of the Solar System; List of natural satellites (moons) Lists of small Solar System bodies; Lists of comets; List of meteor showers; Minor planets. List of minor planets. List of exceptional asteroids; List of minor planet ...
In order to heat a region of very high X-ray emission, over an area of one square arcsec on the Sun, a nanoflare of 10 17 J should happen every 20 seconds, and 1000 nanoflares per second should occur in a large active region of 10 5 × 10 5 km 2. On the basis of this theory, the emission coming from a big flare could be caused by a series of ...
The following is a list of Solar System objects by orbit, ordered by increasing distance from the Sun. Most named objects in this list have a diameter of 500 km or more. The Sun, a spectral class G2V main-sequence star; The inner Solar System and the terrestrial planets. 2021 PH27; Mercury. Mercury-crossing minor planets; Venus. Venus-crossing ...
Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. [1] [2] As one of the founders of the discipline, James Keeler, said, astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space—what they are, rather than where they are", [3] which is studied ...