16
votes
3answers
257 views

Why can't light escape from a black hole?

I've heard that light can't escape from a black hole. Can it? If not, why?
14
votes
2answers
264 views

Why do sunspots appear dark?

Sunspots, such as this one, appear dark: Why?
17
votes
2answers
110 views

Amateur observing targets for binary star systems?

Are there any easily resolvable, binary star, observing targets visible from ~N40°? I'd like to be able to show, in one observing session, Mizar and Alcor (naked eye resolvable), another with ...
11
votes
1answer
71 views

How are the compositional components of exoplanet atmospheres differentiated?

How are exoplanetary atmosphere compositional spectra distinguished from those of the parent star(s), from the composition of the planetary surface or any other factor? Is it actually possible to ...
17
votes
2answers
229 views

How do I calculate the inclination of an object with an amateur telescope?

Suppose I would like to calculate the inclination of a satellite from the ecliptic. Would it be possible to do this with an amateur telescope? How would I go about doing so? Note: A good answer ...

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