Astronomy cast qt.2 part 1

Astro cast 1: Tunguska event: The Tunguska event was an occurence near the Tunguska River in Russia. This event is considered to be an impact of a meteorite. It is really suspected to not be actual impact, but an impact of a column of air created by a meteorite. The object was only suspected to be a few meters across. Despite exploding in the air and causing air to impact the earth, the impact had energy similar to 30 megatons of TNT. It caused a significant amount of destruction, knocking down 80 million trees over 830 square miles. The significance of this occurence is that it has prompted discussion on how to prevent predicted collisions with celestial objects and earth. The lack of residue from impact suggests that the event was caused by a comet. Comets are mainly composed of ice and dust, so any traces of it would be difficult to find. Therefore the Tunguska event could be considered an indirect impact by a comet.

Astro cast 2: Binary Stars: Binary star systems are two stars that revolve around their common center of mass. The larger of the two stars is called the primary, while the smaller is called the either the secondary or the companion. They can be identified using optics or measurements of parallax with devices that allow for both star to be identified. These systems are extremely important because it allows for the mass of the stars to be calculated accurately. Density and radius can be indirectly measured and estimated. There are several different classifications of binary stars. Visual binaries, spectroscope binaries, eclipsing binaries, and astrometric binaries are all observed phenomena. Binary star systems evolve from formation to mass transfer and accretion, finally to nova. Matter can transfer between the two stars, but if the mass cannot be transferred fast enough, it can be lost through solar wind. Contact can sometimes be made and star systems can develop into runaway stars.