Distance is a tricky thing to measure in astronomy. We can’t use tape measures or rulers, and even more sophisticated methods like laser ranging are only good for the very nearest of neighbors, like the moon. That’s where distance indicators like Cepheids come in.
Astronomers use models to derive properties of individual stars that we cannot directly observe, such as mass, age, and radius. This is also the case for a group of stars (a galaxy or a star cluster). One problem with current stellar population models is that they remain untested for old populations of stars. The authors of this paper devise a new way to test models of old stellar populations.
The Pleiades is one of the most well-known open clusters visible with the naked eye from Earth. But just how far away is the cluster? New results help determine a more accurate distance and suggest a troubling error in a previous study.
SciCoder is an annual workshop in New York City for early-career astronomers with the tagline: How I Learned To Stop Hating Coding and Start Getting Things Done.
Different methods of measuring the Hubble constant yield slightly different values, but they are still in reasonable agreement.
Time delays in the light from AGNs’ dusty torii can tell us the intrinsic luminosity and hence the distance to the AGN.
How do pulsating stars give away their secret identities as binary dance partners? In this paper, the authors demonstrate a new way to not only detect binaries we may have missed in the Kepler data, but also to measure their velocities without spectra.
Tune in now for the first extrasolar weather map of a nearby brown dwarf, made using Doppler imaging.
By examining their expansion rate over time, Type II supernovae provide a way to measure extragalactic distances.