Don’t forget, today, 22 April 2009, is Earth Day. Check out the official website for Earth Day here.
In a paper submitted to the Astrophysical Journal, available online now here, astronomers address the modeling of Type Ia supernovae and their progenitors. Type Ia supernovae are those supernovae that develop from a binary star system, wherein one of the stars is a white dwarf which begins to grab material from its binary companion. At some point, called the Chandrasekhar limit, so much matter has been pulled over to the white dwarf that it collapses itself and goes supernova. Type Ia supernovae are believed to be so predictable that they can be used as a cosmic distance indicator, and in fact, it’s Type Ia supernovae which have been used as evidence for the accelerating expansion of the universe and the presence of the so-called dark energy. If our models of Type Ia supernovae and their progenitors are incorrect, there is much in modern astronomy that would need adjustment.
In a paper to appear in the Astrophysical Journal later this year, astronomers provide evidence that there may be yet another planet orbiting Gliese 436. Gliese 436 is a dwarf star over 30 light years distant from our own Sun in the region of Leo. In 2004, astronomers had evidence that there was a Neptune-like planet orbiting Gliese 436, called Gliese 436b. In this paper astronomers “put forward the hypothesis that the Gliese 436 system has an additional, as-yet undetected companion, Gliese 436c.” Learn more about this unconfirmed new exoplanet, online now here.
A group of Indian astronomers have submitted a paper for publication in the Proceedings of the Astronomical Society of the Pacific, available online now here, wherein they outline their “low cost control system for small and medium size” observatory telescopes. The implementation discussed in this paper was specifically for the “IUCAA Girawali Observatory (IGO), that houses a modern 2m, f/10 Telescope at Girawali near Pune India.” Their report should be of interest to both amateur and professional astronomers alike.