25
Nov 10

Pulsating Star Mystery Solved

Source: ESO Science Release eso1046


Artist’s impression of the remarkable double star OGLE-LMC-CEP0227.
Image credit: ESO/L. Calçada

By discovering the first double star where a pulsating Cepheid variable and another star pass in front of one another, an international team of astronomers has solved a decades-old mystery. The rare alignment of the orbits of the two stars in the double star system has allowed a measurement of the Cepheid mass with unprecedented accuracy. Up to now astronomers had two incompatible theoretical predictions of Cepheid masses. The new result shows that the prediction from stellar pulsation theory is spot on, while the prediction from stellar evolution theory is at odds with the new observations. (read more)

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25
Nov 10

Jupiter's belt is coming back

Source: NASA/JPL

New NASA images support findings that one of Jupiter's stripes that "disappeared" last spring is now showing signs of a comeback. These new observations will help scientists better understand the interaction between Jupiter's winds and cloud chemistry.


This is a composite of three color images taken on Nov. 18, 2010, by the Gemini North telescope in Hawaii.
The composite image shows a belt that had previously vanished in Jupiter's atmosphere is now reappearing.
Image credit: NASA/JPL/UH/NIRI/Gemini/UC Berkeley

Earlier this year, amateur astronomers noticed that a longstanding dark-brown stripe, known as the South Equatorial Belt, just south of Jupiter's equator, had turned white. In early November, amateur astronomer Christopher Go of Cebu City, Philippines, saw an unusually bright spot in the white area that was once the dark stripe. This phenomenon piqued the interest of scientists at NASA's Jet Propulsion Laboratory, Pasadena, Calif., and elsewhere.

After follow-up observations in Hawaii with NASA's Infrared Telescope Facility, the W.M. Keck Observatory and the Gemini Observatory telescope, scientists now believe the vanished dark stripe is making a comeback. (read more)

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