Astronomical data gathered over time has gaps. Even the most reliable space telescopes suffer from occasional pauses in their otherwise constant watchfulness. Why are gaps a problem? Can’t astronomers just analyze the short chunks of data that don’t have gaps? The answer: Fourier transforms.
How do stars vary on a hundred year time scale? The DASCH (Digital Access to a Sky Century @ Harvard) Team has been looking back at data taken over the last century in order to answer this question. This paper reports the most recent DASCH discovery, which concerns the star KU Cyg. This is an eclipsing binary system in which a more massive F star is gaining mass from a red giant. The authors noticed a 0.5 magnitude drop in the brightness of the star around 1900 that lasts for five years.
In astronomy everyone shares the same laboratory, the sky. Astronomers with Ph.Ds use giant telescopes to look at the same sky you can walk outside and look up to. Many amateur astronomers have taken advantage of just that….
Stellar variability has received more attention recently due to the problems it poses in the detection of exoplanets; however the study of variability is a field of its own. What causes activity? How does magnetic activity vary with different stars? This paper looks at results from the CoRoT satellite (for Convection, Rotation and planetary Transits), which was launched in December of 2006. This paper is concerned with the long-term photometric microvariability of stars and how stellar activity relates to rotation period and temperature.
Supernovae, the extremely luminous explosions that are the catastrophic deaths of stars, are used directly and indirectly by astronomers of many disciplines. Cosmologists use type Ia supernovae as powerful “standard candles” to probe the farthest rungs of the cosmic distance ladder. Astrochemists studying the interstellar medium (ISM) track supernovae feedback of heavier elements that enrich the ISM. Astrophysicists working on star formation look for evidence of supernovae-induced collapse of molecular clouds. If supernovae are such ubiquitous tools, then it must be essential to understand the actual supernova (SN) mechanism itself.
My first AAS is at a close. On Tuesday, I attended still more talks on exoplanets, some of which I will discuss below, while on Wednesday I manned my poster.