Search results
Results from the WOW.Com Content Network
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 Bortle scale is a nine-level measuring system used to track how much light pollution there is in the sky. A Bortle scale of four or less is required to see the Milky Way whilst one is "pristine", the darkest possible.
John E. Bortle is an American amateur astronomer. He is best known for creating the Bortle scale to quantify the darkness of the night sky. Bortle has made a special study of comets. He has recorded thousands of observations relating to more than 300 comets. From 1977 until 1994 he authored the monthly '"Comet Digest" in Sky and Telescope magazine.
Its apparent magnitude is 4.19, [2] and it can be faintly seen with the naked eye, according to the Bortle scale. Based on parallax estimates made by the Hipparcos spacecraft, the star is located fairly close, about 62.7 light-years (19.21 parsecs) away. [1] 110 Herculis has a spectrum matching that of an F-type main-sequence star.
This system has an apparent visual magnitude of 5.1, [2] which, according to the Bortle scale, makes it faintly visible to the naked eye from suburban skies. Measurements made with the Hipparcos spacecraft show an annual parallax shift of 0.064″, [ 1 ] corresponding to a physical distance of about 51.0 ly (15.6 pc) from the Sun.
Kappa Crateris (κ Crateris) is the Bayer designation for a star in the southern constellation of Crater.It has an apparent visual magnitude of 5.94, [2] which, according to the Bortle scale, can be seen with the naked eye under dark suburban skies.
According to the Bortle scale, it is faintly visible to the naked eye from dark rural skies. The star is located at a distance of approximately 970 light years from the Sun based on parallax , [ 8 ] but is drifting closer with a radial velocity of −7 km/s.
What links here; Related changes; Upload file; Special pages; Permanent link; Page information; Cite this page; Get shortened URL; Download QR code