July 2000

by Steve Stefanik

The month of July is heralded by the giant "J" which adorns the southern sky. This is the constellation Scorpius the scorpion. The very red first magnitude star is Antares which literally means "rival of Mars" in size and color anyway. This is a sure sign that summer has arrived and will be with us in the months ahead. Another sure sign of summer is the "Summer Triangle" rising in the east as the sun sets which consists of the three bright first magnitude stars Vega in the constellation Lyra, Altair in the constellation Aquilla the eagle, and Deneb in the constellation Cygnus the swan. Tracing an imaginary line from each of these stars forms a large triangle in the nightsky overhead.

The evening planets to observe this month are Uranus and Neptune because they are at their brightest for the year. Neptune reaches opposition on the 27th when it will be directly opposite the sun from us and therefore is at its biggest and brightest on that night although only reaching +7.8 magnitude. You will need at least binoculars to spot it among the dim stars of the constellation Capricornus the sea goat. Uranus at magnitude +5.7 is much brighter and bigger so you may be able to spot it using just your eyes on the opposite side of the same constellation.

The planets Saturn and Jupiter provide spectacular views between the open star clusters the Hyades and the Pleiades in the constellation Taurus in the eastern sky before the sun rises. At the beginning of the month they are within a mere 3 1/2 degrees of each other. By month’s end they will have doubled in distance.

In late July the planet Mercury pops above the eastern horizon lower and to the left of Jupiter and Saturn. It reaches greatest elongation 20 degrees from the sun on the 27th.

The planet Venus makes a last minute appearance low on the western horizon on the last day of the month If you have difficulty locating it, you’ll find it within one moon width of the one day old "new moon".