SKYWATCH

May 1997

by Steve Stefanik

"Hats Off to Hale-Bopp"

The month of May begins with comet Hale-Bopp making its grande finale low in the western sky. This will be the last window of opportunity to view this century’s most spectacular comet as it heads for the southern hemisphere. Presently it is among the stars of Taurus the bull, just to the left and above the Pleiades star cluster which makes a pretty picture. In the evening on the 8th, a two day old waxing crescent moon will appear about 5 degrees to the south of it. During the week of the 18th, light from the approaching full moon (which will occur on the 22nd) will obscure its tail. By the time the moon leaves the evening sky in the remaining days of the month, the comet will be lost in the glare of the setting sun and it will set about an hour after the sun goes below the horizon. It won’t be seen for another 5,400 years.

The planet Mars will then become the center of attention high in the southern sky as the comet sets. Look for the -0.1 magnitude red-orange orb just below the hind quarters of Leo the lion. Don’t confuse it with the more yellow-orange star Arcturus in the constellation Bootes which is higher in the sky and toward the east. By the end of the month it will end its backward retrograde motion as Earth pulls away in its shorter faster orbit so that it will appear to be moving eastward again against the background of stars as it moves into the constellation Virgo. A waxing gibbous moon will be between Mars and Spica, Virgo’s brightest star, on the night of the 17th.

The good news is that the stars of summer are already beginning to rise in the east. Scorpio with its bright red first magnitude star Aldebaran rises first followed by Ophiuchus the serpent bearer, Lyra with its bright star Vega, Aquila the eagle with its bright star Altair, and Cygnus and its brightest star Deneb which makes up the so-called "Summer Triangle".

The giant planets Jupiter, Uranus, and Neptune are not far behind rising in the constellation Capricorn a few hours after midnight. Look for the brilliant -2.3 magnitude "morning star" Jupiter in the south by dawn.

Saturn and Mercury make their first appearance near the end of May low on the eastern horizon in the glow of sunrise. Mercury reaches greatest elongation on the morning of the 22nd a mere 5 degrees above the horizon. During this year’s apparition Saturn’s rings with be tilted 10 degrees toward us.

Even the planet Pluto arrives on the scene between the border of Ophiuchus and Scorpio although difficult to spot even with a telescope at a dim +13.7 when it reaches opposition on the 25th.