Thanks to last summer's comet impacts, Jupiter sports a new dark belt in its southern hemisphere, the second-most obvious one on Jupiter after the South Equatorial Belt. Astronomers report that the band looks *bright* at the infrared wavelength of 1.7 microns. This means that debris ejected upward remains suspended high in the atmosphere. Now a team of European astronomers report that the band is significantly dimmer -- and thus cooler -- than its surroundings in the thermal infrared at 7.8 and 7.9 microns. These wavelengths are sensitive to the presence of methane in Jupiter's middle stratosphere. The team suggests either that the stratosphere now contains gases like water, ammonia, and hydrogen cyanide which efficiently radiate energy to space, or that a high-altitude haze above the impact zone is reflecting enough sunlight to keep the gases below relatively cool. Jupiter currently rises more than two hours before the Sun, sitting above the horizon in the southeast to the lower- left of brilliant Venus.
Astronomers at the University of California, Berkeley, have used the 10-meter Keck Telescope on Mauna Kea to record the most distant galaxy yet. Designated 8C 1435+63, this system has a measured redshift, z, of 4.25. Large values of z correspond to fast motion away from Earth and thus great distances, and this galaxy is an estimated 15 billion light-years away. The previous record holder had a redshift of 3.8, though some quasars have redshifts as high as 4.9. Led by Hyron Spinrad, the team finds the new galaxy to be about 150,000 to 200,000 light-years across -- some five times the size of nearby M31, the Andromeda Galaxy. They observed it during March and July last year.
S&T Contributing Editor John Bortle says Periodic Comet Borrelly is an unusual and impressive object. The comet is now about magnitude 8.5, making it easy to spot with modest telescopes or even good binoculars. But through a larger telescope P/Borrelly displays *two* faint tails, pointing toward and away from the Sun at position angles of 265 and 115 degrees. Bortle adds that P/Borrelly hasn't sported an antitail since its apparition in 1918. The comet is now drifting slowly across the western stars of Ursa Major. As 1995 begins you'll find it just barely west of the 3.8-magnitude star Upsilon Ursae Majoris. Here are upcoming positions for 0 hours Universal Time:
R.A. (2000) Dec.
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Jan 1 9h 50m +59.2 deg
3 9 51 +60.3
5 9 52 +61.3
This year the Quadrantid meteor shower should peak at about 23:00 Universal Time on January 3rd. This shower is known for its sharp peak, but despite Moonless skies this year the peak occurs during daylight in North America. Viewers in Eastern Asia stand to have the best seats for seeing the crescendo in predawn darkness.
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