## Angular Resolution of a Telescope

3 posts / 0 new
Offline
Last seen: 4 weeks 1 day ago
Joined: 04/12/2020 - 23:14
Angular Resolution of a Telescope

Angular resolution in radians = 1.22 times the quotient (wavelength / aperture)

Make sure to keep the units the same, wavelength may be in angstroms; aperture may in inches. So, do the conversions first.

For example, a telescope with a 10-inch lens is assumed to be observing in the visible spectrum. Assume the middle range. The last step is to convert radians to arc seconds.

My telescope has an aperture of 102 mm.

Answer ranges 0.98" (violet) to 1.72" (red)

Offline
Last seen: 4 weeks 1 day ago
Joined: 04/12/2020 - 23:14
Self-Paced Learning

The example comes from  A Student's Guide to the Mathematics of Astronomy by Fleisch & Kregenow, Cambridge University Press, 2013.

Offline
Last seen: 18 hours 1 min ago
Joined: 24/03/2018 - 15:17
Approximation.

You give the accurate (and correct) procedure.  For a decent approximation I just divide 140 by the aperture in mm, which gives an answer which is "good enough".  In your case 140/102 = 1.37.

Easy to remember.

 © The British Astronomical Association 2021 Registered charity no. 210769 Registered company no. 117572 For more information including contact details, click here. Website designed by Dominic Ford. Top banner image:C/2012 X1 LINEAR, by Damian Peach.