My first Magazine Sky & Telescope - 04.2019

APRIL 2019 OBSERVING Sun, Moon & Planets by Fred Schaaf To fi nd out what’s visible in the sky from your location, go to skypub.com/ almanac. Planets, Bright and Minor Five bright planets grace the skies from dusk to dawn, and a minor planet comes to opposition. n the early evening, Mars is almost halfway up the western sky in Taurus. Mars sets in the hour before midnight and is replaced by the rising of bright- ening Jupiter in the east. Saturn comes up somewhat later than Jupiter, and by late April the two planets are to either side of the meridian as dawn brightens. Venus starts rising in morning twilight, with Mercury following it even lower in the dawn glow. I DUSK THROUGH EVENING Mars sets more than 4 hours after the Sun (for viewers around latitude 40° north) as April begins, less than 3½ hours by month’s end. The planet fades a bit more (magnitude 1.5 to 1.6) and shrinks a bit more (4.6″ to 4.2″ wide). But Mars takes a scenic trek through Taurus in April. It begins the month only about 3° left of the Pleiades, then spends the ﬁ rst week of April marching between the Pleiades and the Hyades. Not until April 16th does Mars pass 7° north of now-considerably brighter Aldebaran. At month’s end Mars is still around 6° degrees lower left of Beta Tauri (El Nath) — a star that is then vir- tually identical to Mars in brightness. ALL NIGHT Pallas is at opposition on April 6 in Boötes near Muphrid (Eta Boötis) — see page 48 for details. MIDNIGHT TO DAWN Jupiter doesn’t rise until after 1 a.m. at the beginning of April. By month’s end, the giant planet rises above the horizon a little after 11 p.m., just as Mars is set- ting. Unlike currently lackluster Mars, April 7–9 April 5 Around 9 pm Around 9 pm Moon Apr 9 Aldebaran Mars Pleiades Aldebaran Mars Jupiter dominates its region of the sky, its brightness improving from magni- tude –2.3 to –2.5 in April. Jupiter is best seen, especially in telescopes, when it’s at its highest in the south, which hap- pens about 1 to 2 hours before sunup this month. Jupiter’s apparent equato- rial diameter does increase from 40″ to more than 43″ during the month. On April 10th, exactly two months before Jupiter reaches opposition, the gas giant begins retrograde motion, starting to head slowly westward relative to the background stars of Ophiuchus. This movement will bring Jupiter back much closer to Antares by early summer, but in April the planet seems to hover about 15° left or upper left of the star in the early morning sky. Saturn comes up around 3 a.m. on April 1st but about 1 a.m. on April 30th. tqu These scenes are drawn for near the middle of North America (latitude 40° north, longitude 90° west); European observers should move each Moon symbol a quarter of the way toward the one for the previous date. In the Far East, move the Moon halfway. April 14 –15 Moon Apr 8 TA U R U S Pleiades Around 10 pm Sickle of LEO TAURUS 10° Moon Apr 7 Regulus Moon Apr 14 Moon Apr 15 Looking West 46 A PR I L 2 019 • SK Y & TELESCOPE Looking West Looking South, very high in the sky

My first Magazine Sky & Telescope - 04.2019 | Page 48