stars, galaxy,

Astronomers Asking You to Help Solve Mystery of Dimming Star

August 28, 2009 09:00 AM
by Haley A. Lovett
The nearly 200-year-old astronomical mystery that is epsilon Aurigae could be solved in the next few years, thanks to amateur astronomers and the Internet.

The Mystery of Epsilon Aurigae

Epsilon Aurigae is a star system that varies in brightness over time. It is thought that epsilon Aurigae consists of two stars or large masses orbiting around a common center. When one of the stars blocks the other, it would create a dimming effect to a viewer on Earth. 

According to Citizen Sky, Johann Fritsch was the first person to notice that epsilon Aurigae is a variable star (that it was getting dimmer and brighter). Later, astronomers observed a potential cycle of eclipse in the late 1840s, and every 27 years since then the star appears to go dim for about two years.

“So what’s the mystery?” asks Citizen Sky. Astronomers have not observed any light from the second star. Also, during the middle of the eclipse period, there are a handful of days when epsilon Aurigae gets temporarily brighter again before returning to its dim state.

Since the 1930s, astronomers have presented theories to explain the “invisible second star.” According to the American Association of Variable Star Observers, at first astronomers thought the second star in the system was “semitransparent.” Later it was suggested that a large disc of matter was the object eclipsing the first star, but neither hypothesis could explain the temporary brightening of the star mid-eclipse.

The most promising theory today is that the second object is a flat disc of matter, but that it has a hole in the middle. On Earth, we see the disc as tilted toward us and not straight on so that at some point during the eclipse, we get a glimpse of the first star through the hole.

Due to the fact that epsilon Aurigae eclipses every 27 years, scientists only have a few opportunities every century to gather data about the mysterious star. According to Hadley Leggett writing for Wired Magazine, epsilon Aurigae is too bright for professional telescope equipment to observe it. As a result, astronomers are asking regular citizens to observe and report on the brightness of the star during the next dimming. They hope that that data can provide clues as to “the star’s curious companion,” Leggett writes.

Key Discoveries by Amateur Astronomers

It isn’t uncommon for amateur astronomers to make new discoveries. After all, anyone on Earth can observe the night sky, and it’s filled with a vast number of stars and other objects.

According to ABC News, the comet Hale-Bopp was named after its two discoverers; one, Alan Hale, was an astronomer, the other, Thomas Bopp, was a construction worker. When legendary astronomer William Herschel discovered Uranus in 1781, he was working as musician. In late July, Anthony Wesley, an amateur Australian astronomer, noticed that an object had hit Jupiter and left a scar on the planet; he noticed the incident before NASA.
With the publication of many telescope images online, amateur astronomers need not leave their computers to make discoveries. In December 2008, a schoolteacher was going through images published by Galaxy Zoo, a project that utilizes the manpower of the masses to help identify any unusual objects in a catalog of millions of telescope photos, and found an unusual greenish gas cloud. It was later found that the green color was caused by radiation from a black hole.

Resources for the Amateur Astronomer

To take part in the Citizen Sky project and help unlock the mystery of epsilon Aurigae, visit Citizen Sky.

FindingDulcinea’s Web Guide to Astronomy has a list of resources to help you get involved—either as an amateur or as a professional—in the astronomy community. You’ll also find maps, sky charts and beginners tips to help you get familiar with the constellations, planets and known objects in the sky

NASA’s Astronomical Data Center also has a page of resources for the amateur astronomer that can help you get started in observing the night sky.

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