Question

An observatory telescope consists of four 40cm f/2.5 telescopes on a single equatorial mount, with each telescope being equipped with an 8208 x 6164 pixel CCD with 6 um pixels

a. what is the focal length of the observatory telescopes?

b. what is the pixel scale of the telescopes in arcseconds per pixel?

c. what is the rectangular field of view of each telescope. Give an answer in degrees by degrees.

Answer 1

Given that

4 telescopes with 40 cm f/2.5

we know that f ratio = focal length/aperture diameter

focal length = aperture diameter f ratio

here, f ratio = 2.5

aperture diameter = 40 cm

so focal length f =

again, CCD scale = 8208 6164

pixel size =

we know that

image scale (in arcsec / mm) = 206265/aperture in mm f ratio

image scale = arcsec/mm

pixel scale per 1 pixel = image scale in arcsec / mm pixel size in mm

= arc sec

sky coverage per axis = sky coverage per pix in arcsec no of pixels

for x axis, we have

sky coverage = arc sec

for y axis, we have

sky coverage = arc sec

so rectangular field of view of each telescope =