Periodic comet 17P/Holmes flashed a half a million times brighter than usual at the end of last month, going from a magnitude of about 17 to about 2.8. Now, a new Hubble Space Telescope photo of the comet reveals an intriguing bow-tie structure around its nucleus.

Over the past three weeks, Comet Holmes' cloud of haze has spread out to a diameter of 900,000 miles, larger than our Sun. Hubble's Wide Field Planetary Camera 2 took a picture of Holmes, peeking through its cloud to reveal the comet's structure. This picture, released yesterday, was taken Nov. 4.

"Most of what Hubble sees is sunlight scattered from microscopic particles," explained Hal Weaver of The Johns Hopkins University Applied Physics Laboratory in Laurel, Md., who led the Hubble investigation. "But we may finally be starting to detect the emergence of the nucleus itself in this final Hubble image."

Comet Holmes was discovered by Edwin Holmes in 1892 while he was conducting regular observations of the Andromeda Galaxy (M31). It was noticed due to a similar outburst like that noticed on Oct. 23-24 this year. Calculations in the mid-twentieth century established the perihelion date as June 13 and the orbital period as 6.9 years. Comet Holmes is now 149 million miles from Earth.

On Monday, Nov. 19, the Holmes will create a unique skywatching event with its see-through coma, according to the Web site Spaceweather.com: "The comet will glide by the star Mirfak [also called Alpha Persei] and appear to swallow it — a sight not to be missed," the website reads.

Weaver also told Reuters that astronomers suspect that volatile ices within the nucleus heated up during the comet's swing around the sun, building up pressure that was released months later by an explosion.