Questions on observational astronomy, optics, and astrophysics. Specializing in the evolution of stars, variable stars, supernovae, neuton stars/pulsars, black holes, quasars, and cosmology.
I was a professional astronomer (University of Texas, McDonald Observatory), lecturer at the Adler Planetarium, professor of astrophysics, and amateur astronomer for 42 years. I have made numerous telescopes, and I am currently building one of the largest private observatories in Canada.
StarDate, University of Texas, numerous Journal Publications
Hi Corissa, The answer is gravity. The same thing that keeps the earth together also keeps the stars together. But stars are gas, aren't they? Yes, but even the gas molecules are attracted to other
Hi Richard, I'm not sure if that's actually been proposed in any peer-reviewed publication, but I don't see why that can't be viewed as one possible "explanation". Of course, we'd have to come up with
Hi Maria, Humans have imagined all sorts of constellations before, but all were made up of the same stars we see today. In 1922, we adopted an "official" list of 88 constellations. Please see https://en
Hi Maria, No, astronomers are not very concerned with the way constellations will appear in the future, although they are very concerned with the positions of stars (and their positions do make up the
Hello Kaitlyn, This is a common misconception about black holes. Black holes do not have any more gravity than any other body of the same mass! To explain, suppose our sun suddenly collapsed to become