by Dan Gifford | Nov 29, 2011 | Daily Paper Summaries
Using a clever technique, the authors identify a sub-population of rotating Wolf-Rayet stars.
by Nathan Sanders | Nov 28, 2011 | Daily Paper Summaries
The latest episode in the saga of GJ1214b appeared on the arXiv Wednesday.
by Shannon Hall | Nov 28, 2011 | Current Events
On Saturday November 26th NASA launched its newest rover toward Mars. Its key goal is to search for evidence that the planet may once have held microscopic life and to look at the possibility of once again holding life. Presented here are the details concerning the mission and the rover itself.
by Nick Hand | Nov 26, 2011 | Daily Paper Summaries
Researchers at Penn State aim to determine the probability that artifacts from allien civilizations are present in our Solar System.
by Guest | Nov 26, 2011 | Guides
This post is written by Benjamin Nelson, a graduate student in the Astronomy Department at the University of Florida. He works with Dr. Eric Ford on the characterization and dynamical evolution of extrasolar planets. He is currently developing an N-body Markov chain Monte Carlo for RV observations of exoplanet systems. Why is this important to astronomy? Inevitably in your astronomical career, you’ll attend some talk where the speaker mentions “MCMC” and “Metropolis-Hastings”, or maybe something about “priors” and “likelihood functions.” The latter terms refer back to a Bayesian framework, while the former terms are the numerical tools, both of which are rarely covered in undergraduate astronomy/physics. Although Bayes’ theorem has been around for more than 200 years, computational advances within only the past couple decades have made it actually practical to solve problems involving Bayesian techniques. Learning statistical methods is like eating your vegetables: you probably won’t enjoy it, but it’ll be good for you in the long run. It is hardly motivating for an astronomy grad student to pick up an introductory book on Bayesian statistics without some practical application in mind, but a solid knowledge of Bayesian methods is a great way to find common ground in other, unfamiliar astronomical subfields, or even other disciplines of science. The purpose of this astrobite is to familiarize the reader with conventional Bayesian jargon (sugar coated with some astronomy) and lay out the ingredients to code a Markov chain Monte Carlo from scratch. Bayes’ Theorem: In short, Bayes’ theorem allows us to update our knowledge of a model system using new sets of observations. We use this to quantify the...
