Search results
Results from the WOW.Com Content Network
mean brightness [42] −1.66: planet Jupiter: seen from Earth 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 ...
[8] [9] Every interval of one magnitude equates to a variation in brightness of 5 √ 100 or roughly 2.512 times. 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.
Sky Quality Meter model SQM-L. A sky quality meter (SQM) is an instrument used to measure the luminance of the night sky, more specifically the Night Sky Brightness (NSB) at the zenith, with a bandwidth ranging from 390 nm to 600 nm. [1]
limiting magnitude with 12.5 in (32 cm) reflector is 17.5 (with effort) Venus and Jupiter affect dark adaptation; 2 Typical truly dark site 7.1–7.5 21.6–21.75 the zodiacal light is distinctly yellowish and bright enough to cast shadows at dusk and dawn; airglow may be weakly visible near horizon; the gegenschein is visible
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]
Starlight overcast moonless night sky [1] 140 microlux: Venus at brightest [1] 200 microlux: Starlight clear moonless night sky excluding airglow [1] 10 −3: 1 millilux: 2 millilux: Starlight clear moonless night sky including airglow [1] 10 −2: 1 centilux: 1 centilux: Quarter Moon 10 −1: 1 decilux: 2.5 decilux: Full Moon on a clear night ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
The Guide Star Catalog is an online catalogue of stars produced for the purpose of accurately positioning and identifying stars satisfactory for use as guide stars by the Hubble Space Telescope program. The first version of the catalogue was produced in the late 1980s by digitizing photographic plates and contained about 20 million stars, out ...