October 17, 2017

AstroEvent: When will Epsilon Aurigae Brighten?

One of the strangest variable stars is worth watching this spring.  Back in 2009, we alerted viewers to monitor the curious variable Epsilon Aurigae. Once every 27.06 years, this star dips nearly a magnitude in brightness down to about +3.8, markedly discernable to the naked eye. This drop lasts for over a year before Epsilon Aurigae returns to its former self. This spring should witness such an occurrence.

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08.04.10-Epsilon Aurigae Update.

   We couldn’t resist shooting this one out there today, as it contains some fairly mind-blowing imagery. Late last year, we put a shout-out to observe the eclipsing binary star Epsilon Aurigae, a bright naked eye star that undergoes periodic diming once every 27 years. For over 190 years, this star has stubbornly not only refused to match stellar evolutionary models, but sometimes threatened to overthrow them, to boot. Now, scientists have solved the case of the disappearing star, and it’s a strange one, indeed. The variation in brightness appears to be the result of three factors; a bright type F supergiant, orbited by a hot type B star about 1,000 times dimmer shrouded in a massive dust disk. The entire system passes along our line of sight and obscures the host for an 18 month period. The grouping is about 2,000 light years distant. In fact, if Epsilon Aurigae were tipped away even 10 degrees more from our line of sight, we wouldn’t see anything unusual at all! This model of the systems’ total luminous output matches the observed brightness curve from the recent dimming. (see above) [Read more...]