Search results
Results from the WOW.Com Content Network
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).
The Sun is the brightest star as viewed from Earth, at −26.78 mag. The second brightest is Sirius at −1.46 mag. For comparison, the brightest non-stellar objects in the Solar System have maximum brightnesses of: the Moon −12.7 mag [1] Venus −4.92 mag; Jupiter −2.94 mag; Mars −2.94 mag; Mercury −2.48 mag; Saturn −0.55 mag [2]
maximum brightness −9 to −10: Phobos (moon) seen from Mars maximum brightness −7.50: supernova of 1006: seen from Earth the brightest stellar event in recorded history (7200 light-years away) [38] −6.80: Alpha Centauri A: seen from Proxima Centauri b [39] −6.00: The total integrated magnitude of the night sky (incl. airglow) seen from ...
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 ...
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 .
The scale is logarithmic and defined such that a magnitude 1 star is exactly 100 times brighter than a magnitude 6 star. Thus each step of one magnitude is 100 5 ≈ 2.512 {\displaystyle {\sqrt[{5}]{100}}\approx 2.512} times brighter than the magnitude 1 higher.
10 −5: 10 −4: 10 −3: mcd/m 2: 100 μcd/m 2: Cloudy night sky without moon [4] 400 μcd/m 2 "Darkest sky" [5] 1 mcd/m 2: Night sky [6] 1.4 mcd/m 2: Typical photographic scene lit by full moon [7] 10 −2: 5 mcd/m 2: Approximate scotopic/mesopic threshold [8] 10 −1: 10 0: cd/m 2: 2 cd/m 2: Floodlit buildings, monuments, and fountains [9 ...
(The S 10 unit is defined as the surface brightness of a star whose V-magnitude is 10 and whose light is smeared over one square degree, or 27.78 mag arcsec −2.) The total sky brightness in zenith is therefore ~220 S 10 or 21.9 mag/arcsec² in the V-band. Note that the contributions from Airglow and Zodiacal light vary with the time of year ...