- 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...
-
Robby Blake Bortles (born
April 28, 1992) is an
American former professional football quarterback who pla**** in the
National Football League (NFL) for...
- 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...
-
horizon are to all
intents and
purposes unobservable.
Bortle, John E. (February 2001). "The
Bortle Dark-Sky Scale". Sky & Telescope. Sky
Publishing Corporation...
- 469–71. Bibcode:1922PA.....30..469R.
Wagman 2003, p. 60.
Bortle, John E. (February 2001). "The
Bortle Dark-Sky Scale". Sky & Telescope.
Archived from the original...
-
International Astronomical Union.
Retrieved 1
September 2015.
Bortle, John E. (February 2001). "The
Bortle Dark-Sky Scale". Sky & Telescope. Sky
Publishing Corporation...
-
Laustsen et al., Pasachoff, Jones, van der Kruit, and
Hodge et al. See also
Bortle Dark-Sky Scale. The
bright center of the
galaxy is
located in the constellation...
-
resulting in a "headless"
comet similar to
Comet Lovejoy in 2011. John
Bortle considers the
comet due to its
brightness and
night time
appearance as the...
- Year
Title Director 2014 "Flip Flops"
Brett Bortle 2016 "Boom Boom"
Stokes Nielson 2017 "Dirty South" Jeff
Johnson 2018 "Power of Garth" Jeff Johnson...
-
Publishing Company. p. 290. ISBN 978-0-939923-78-6.
Bortle, John E. (February 2001). "The
Bortle Dark-Sky Scale". Sky & Telescope. Sky
Publishing Corporation...
