Search results
Results from the WOW.Com Content Network
Consequently, a magnitude 1 star is about 2.5 times brighter than a magnitude 2 star, about 2.5 2 times brighter than a magnitude 3 star, about 2.5 3 times brighter than a magnitude 4 star, and so on. This is the modern magnitude system, which measures the brightness, not the apparent size, of stars.
minimum brightness [42] −1.47: star system Sirius: seen from Earth Brightest star except for the Sun at visible wavelengths [45] −0.83: star Eta Carinae: seen from Earth apparent brightness as a supernova impostor in April 1843 −0.72: star Canopus: seen from Earth 2nd brightest star in night sky [46] −0.55: planet Saturn: seen from Earth
ζ Eridani (Latinised to Zeta Eridani) is the binary star's Bayer designation.WDS J03158-0849 A is its designation in the Washington Double Star Catalog.The designations of the two components as WDS J03158-0849 Aa and Ab derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).
By comparing this known luminosity to an object's observed brightness, the distance to the object can be computed using the inverse-square law. These objects of known brightness are termed standard candles, coined by Henrietta Swan Leavitt. [13] The brightness of an object can be expressed in terms of its absolute magnitude. This quantity is ...
This is a list of stars arranged by their apparent magnitude – their brightness as observed from Earth. It includes all stars brighter than magnitude +2.50 in visible light, measured using a V-band filter in the UBV photometric system.
The Bortle dark-sky scale (usually referred to as simply the Bortle scale) is a nine-level numeric scale that measures the night sky's brightness of a particular location. It quantifies the astronomical observability of celestial objects and the interference caused by light pollution .
Factor ()Multiple Value Item 0 0 lux 0 lux Absolute darkness 10 −4: 100 microlux 100 microlux: Starlight overcast moonless night sky [1]: 140 microlux: Venus at brightest [1]: 200 microlux
An idealized case of limb darkening. The outer boundary is the radius at which photons emitted from the star are no longer absorbed. L is a distance for which the optical depth is unity. High-temperature photons emitted at A will just barely escape from the star, as will the low-temperature photons emitted at B. This drawing is not to scale.