Get ready to see "celestial fireworks" in the sky by mid century

Washington, June 6 : Astronomers have announced that within a few decades, people can expect to see celestial "fireworks", which would be visible from Earth.

According to a report in National Geographic News, the center of attraction in this cosmic display would be Epsilon Aurigae, a supergiant F-type star that is considered one of the most unusual objects in the sky.

Even though it is about 242 million miles (389 million kilometers) wide, Epsilon Aurigae is totally eclipsed every 27 years by an even bigger disk-shaped neighbor.

Astronomers don't know what the star's colossal partner is, but one leading theory suggests it's a gas cloud more than a thousand times as wide as the sun that harbors two small stars at its core.

Alternatively the object at the center of the cloud may be a black hole or a single larger star that has somehow siphoned gas from Epsilon Aurigae to create an enveloping cloak of darkness.

Each eclipse lasts nearly two years, by far the longest in any known binary star system. The next eclipse starts in August 2009 and should run through May 2011.

But marked changes in the behavior of the massive star and its enigmatic companion suggest that a third object is about to crash the affair.

"It has prospects to produce a bit of fireworks by mid-century," said Robert Stencel, an astronomy professor at the University of Denver in the US.

According to Stencel, a third object in the system-possibly a planet embryo, or planetesimal-is spiraling toward the supergiant or the stars at the center of the eclipsing object.

As its orbit shrinks, the planetesimal passes in front of Epsilon Aurigae more frequently, which could explain the shortening of the bright-dim cycle.

Eventually, the planet embryo would crash into the star or its partner.

This would create bright flares like those seen in some types of interacting stellar binaries or recurring novas, where one star draws gas from its companion until it passes a critical mass limit and explodes.

Such flares in the Epsilon Aurigae system would cause a brightening visible to observers on Earth with the naked eye.

"That could pop it up to become one of the brightest objects in the sky," said Stencel.

ANI