Skywatch Line for Friday, June 20, through Sunday, June 22, written by Sam Salem
This is Dudley Observatory’s Skywatch Line for Friday, June 20, through Sunday, June 22, written by Sam Salem.
On Friday, Sun rises at 5:17am and sets at 8:37pm; Moon rises at 1:30am and sets at 3:18pm.
Friday is the longest day and the shortest night of the year for the Northern Hemisphere. Summer begins at the solstice, 10:42pm, Friday night. The midday Sun passes the closest it ever can to being straight overhead. On that day, the shadow becomes the shortest it can ever be where you live.
Mark where the Sun sets as seen from a particular spot. In a few days you should be able to notice that the Sun is starting to set a just little south, or left, of that point as it begins its six-month journey to the winter solstice.
Shortly before sunrise on Saturday morning, the thin waning crescent Moon will lie near Venus. On Sunday morning, the thinner crescent Moon will float between Venus and the Pleiades star cluster. Watch for the glow of earthshine on the unlit portion of the Moon.
Venus, at magnitude –4.3, rises in the east-northeast shortly before the beginning of dawn. In a telescope, Venus’ shrinking globe appears just past half lit, very slightly gibbous.
On Friday night, watch Mars and Regulus draw farther apart as they sink in the west during and after late twilight. On Friday night, they will be 2° apart. In a week they’ll be 6° apart and somewhat lower. In a telescope, Mars appears as a tiny blob 5 arcseconds in diameter. However, it’s extended than point-like Regulus.
Saturn, at magnitude +1.1 at the border of Aquarius and Pisces, rises around 1 am. Find Saturn in early dawn, about four fists at arm’s length upper right of Venus. Try a telescope on Saturn just as dawn is beginning. This is the time when Saturn is high out of bad seeing but still stands out against a reasonably dark sky. Saturn rings are nearly edge on this year.
Neptune, at magnitude 7.9, lies in Saturn’s background, about 1° from it. Try to catch the outermost major planet before dawn begins. Use a finder chart for Neptune with respect to Saturn.
Orange star Antares, the brightest star in the constellation Scorpius, is often referred to as the “Betelgeuse of summer” because it shares a similar reddish-orange color and is a bright, prominent star in the summer sky. Both are 1st-magnitude “red” supergiants.
Look southeast for orange Antares.
Around and upper right of Antares are the other, whiter stars of upper Scorpius, forming their distinctive pattern. The rest of the Scorpion runs down from Antares, then left.