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    1)An astronomer wishes to resolve a binary star with a separation of 0.8arcseconsa using a filter at 500nm. Ignoring the effects of the atmosphere, what is the minimum size of the telescope needed to resolve the binary? (base your answer on the size of the airy disk)
    : using raleighs criterion i got this to be 0.157 metres in diameter, though i can't tell what it means to base my answer on the size of the Airy disk?
    2) The seeing is typically measured to be FWHM - 0.7arcsec at wavelength 2.2um (i.e in the near infrared) at the site which the telescope is located. Will the astronomer be able to resolve the binary star in an observation at 500nm with a telescope 1 metre from the site?
    : this is where i get really stuck, I'm not really sure how to include FWHM in my calculation and i can't find many resources to help
    3) the same astronomer would like to observe the pleiades star cluster with the 1 metre telescope from part 2. Plaiedes subtends 2 degrees on the sky. A camera that contains CCDS that cover a square 10x10cm area of the focal plane at the f/2 prime focus of this telescope is available. Can the astronomer fit Pleiades within a single observation with this camera?

    Any help with these would be greatly appreciated. I asked my tutor however he's not an astrophysicist so didn't really know where to start. Thanks
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Updated: November 2, 2017

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