simulate_a_telescope() function fix

[cleber-si]

Hi!

I'm excited to simulate some light curve for a project I'm developing and I ran into some trouble getting it done. More specifically, I was running "part 2" of Example 3 notebook to do so. When simulating telescopes with uniform_sampling = False, I received a NonRotationTransformationWarning warning for SAAO_I and SSO_I. I'm sending the cell output in a .log file: example3_debug.log

The notebook's kernel died when trying to simulate CTIO_I and CTIO_V. The problem was that the Moon_separation was mixing ICRS (target) with AltAz (Moon). Astropy warns because the transform isn’t a simple rotation. Since it was a simple problem, I solved this issue with the proposed patch. Below is a summary of the changes.

Fix: compute Moon/target separation in a single AltAz frame; keep Time object (no .isot)

• Build one AltAz frame with (obstime, location) and reuse it
• Transform target, Sun and Moon into the same frame before geometry
• Replace target.separation(Moon_altaz) with target_altaz.separation(Moon_altaz)
• Avoid altitude tuple (no trailing comma)
• Document/normalize Moon illumination units (fraction vs percent)

Signed-of-by: Cleber Silva (clebersilva@fisica.ufc.br / cleber_si@outlook.com)