Stars Is it possible to see a star’s disk? I’ve heard that Betelgeuse has been imaged, but what about the Alpha Centauri system or other stars?
Science Ask Astro web extra: Does a star stay at the same spot in the sky everyday? If not, is it considered a star, or some other unidentified object?
Robotic Spaceflight Hubble is in space and the mirror is exposed, so how has the mirror stayed clean? Is it possible that space debris and micro particles could hit it?
Stars How can we tell if a star belongs to a star cluster or is in the space between the cluster and the observer?
