OFFSET
1,2
COMMENTS
The angular resolution (diffraction limit), in radians, is this constant times the wavelength of the light used divided by the aperture diameter. That is: objects closer than this angle cannot be resolved as separate objects.
Note that the small angle approximation sin(theta) =~ theta can be used. Also, a commonly used approximation to this constant is 1.220. - John W. Nicholson, Jul 29 2014
For example, a radio telescope with a 300-meter aperture observing at the hydrogen line (21.106... cm) can distinguish objects at most 0.04916... degrees apart. - Charles R Greathouse IV, Mar 08 2018
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..10000
COSMOS - The SAO Encyclopedia of Astronomy, Rayleigh Criterion
Rene Kay, Todd Kay, Planet Seeker Interferometer (PSI), hal-02870885v2 [astro-ph.IM], 2020.
Wikipedia, Angular resolution
Wikipedia, Diffraction-limited system
EXAMPLE
1.21966989126650445492653884746525517787935933077511...
MATHEMATICA
RealDigits[ BesselJZero[1, 1]/Pi, 10, 111][[1]] (* Robert G. Wilson v, Jul 23 2014 *)
PROG
(PARI) solve(x=3, 4, besselj(1, x))/Pi
(PARI) besseljzero(1)/Pi \\ Charles R Greathouse IV, Aug 09 2022
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Charles R Greathouse IV, Jul 22 2014
STATUS
approved