February 19, 2019

25.04.10-First Extra-solar Magnetic Loop Recorded.

Radio-Interferometry has really shown its stuff as of late. Recently, astronomers have used a collaboration of radio telescopes based planet-wide to study a familiar variable star; Algol in the constellation Perseus. Known since Arabic times as “The Demon Star,” Algol is an eclipsing binary, where two stars are locked in a 5.8 million mile embrace and “eclipse” each other from our vantage point. This explanation has been known since 1889, but radio astronomers have added another unique feature to the pair; a long pair of magnetic loops connecting the two stars. “This is the first time we’ve seen a feature like this in the magnetic field of any star other than the Sun,” stated William Peterson of the University of Iowa. The scopes linked included the NSF’s Very Long Baseline Array, Green Bank, and the Effelsburg Radio telescope based in Germany.  Collectively, the setup is known as the High Sensitivity Array. Algol is about 93 light years distant, and is a variable star that can be easily monitored by even beginning amateurs with the naked eye.

10.04.10- Radio Astronomers Refine Celestial Grid.

Getting a good fix on positions both on the Earth and in the sky is tougher than it may sound. Tectonic plates move. The Moon raises tides under our feet. The whole planet orbits our Sun, which is itself flying about the galaxy and getting jostled by other stars, as the galaxies themselves are flying apart. Last year, however, astronomers at the National Science Foundation’s Very Long Baseline Array of radio telescopes tackled the problem in a novel way. Using 35 radio telescopes worldwide, they monitored and measured the positions 243 quasars over a 24 hour period starting November 18th 2008. Quasars are ideal candidates for this kind of measurement because of their extreme distance. These high precession measurements break the old record for the most radio dishes employed, which stood at 23. The telescopes utilized a method known as Very Long Baseline Interferometry, which combines simultaneous signals collected over individually spaced telescopes to increase resolution power. Headquartered in Socorro, New Mexico, the VLA’s data will not only refine astronomical measurements, but increase the accuracy of geophysical science as well.