Planet visible all night: Saturn ©ABRAMS PLANETARIUM reaches opposition on April 3 and Use this scale to measure for several days it is up all night, angular distances between Planetarium business office: objects on diagrams below. shining at mag. +0.4 in Virgo. (517) 355-4676 SKY CALENDAR APRIL 2011 In April, Saturn is 11°-13° NW of Night Sky Notes on World Wide Web: 0° 10° 20° Spica and 3.8° to 1.6° ESE of http://www.pa.msu.edu/abrams/nightskynotes/ An aid to enjoying the changing sky 3rd-mag. Gamma Virginis. Watch Saturn retrograde (go west against SUNDAY MONDAY TUESDAY WEDNESDAY THURSDAY FRIDAY SATURDAY star background) until it is 1/4 degree from Gamma Vir in early Fri & Sat Sunday Apr 3, 1-1/2 hrs after sunset One hour One hour Thurs Friday April 1, June. (This author followed a Apr 1 & 2, Saturn at opposition in Virgo, Pleiades after sunset after sunset Bull’s Apr 7 45 min before sunrise similar, but much closer pairing of morning 11.2° NW of Spica, horns Venus- Saturn with Gamma Virginis two twilight: 4.6° NW of Theta, Gamma Jupiter in Betelgeuse Saturn Saturn-years [59 Earth-years] ago, See end of Wed 6 Fri 8 Venus in the spring of 1952. That and a and 3.6° ESE of Gamma. conjunction 150° Moon this row. N’most Moon gathering of Saturn, Mars, and with Sun Orion’s apart E ESE Spica in Virgo that spring and Sunday Apr 6. belt in a.m. Saturn other sky events planted the seeds April 3: Arcturus sky. for an eventual career choice to When Saturday April 2, share the beauty of the sky.) Seen Aldebaran Thurs 7 Theta Tues Apr 5 ARIES will you 30 min before sunrise at dusk in April 2011, Saturn New Moon last see begins low, S of E, and climbs to Hawaii may spot Venus 10:32 a.m. Rigel Pleiades both some 35° up in SE by month’s end. Hyades Mars rising 6° LR EDT, 30 hrs Spica simul- At dawn it begins April low in WSW, Old of Moon and sets in midtwilight by month’s after most Young Moon tane- (binocs). E ESE W WNW Moon E ESE end. Rings: See April 23. distant Moon Mon Apr 4 Wed 6 ously? Planets at dawn: Venus rises of year. from 1.3 hours to one hour before Tues April 12, Gamma sunup (from lat. 40° N). At dawn Pollux Castor 1-1/2 hours Wed 13 1-1/2 hours Sat Apr 16, midtwilight it’ll be easy to spot the after sunset 45 minutes Spica after sunset Saturn Vir one hour –3.9-mag. planet, very low in ESE before SICKLE Mon 11 GREAT at after sunset shifting to E as month progresses. sunrise past First Qtr Moon occults SQUARE opposition, Saturn remains above W horizon Capella LEO Moon Zeta Gem from OF visible after Venus rises, but by an interval passes some locations all shrinking to only 12 min. by April 30. PEGASUS widely (8°) (Mutual opposition of Venus-Saturn Sunday night. Regulus Procyon Spica S of occurs on May 1.) Mercury emerges Apr 10 Kids Saturn- Saturn. in twilight to LL of Venus in April’s approaching Spica Wed 13 CORVUS final week, brightening enough for First Qtr Sat Apr 9 12.0° binoculars and even naked eye, Venus apart on Denebola especially from south of lat. 40° N. Lion’s tail Mercury in ENE E April ESE SE See April 24-30. Mars (mag. +1.2) Bull’s 14 & 15. Thurs 14 and Jupiter (mag. –2.1) can by inferior conj Apr 9. horns spotted nearby, at first only from Fri 22 Gamma Vir Beta southern and SW states and Sat 23 S’most Moon Moon, week of April 17-23, Sunday Four Sat Saturn Alpha Hawaii. Diagrams for April 25-30 Thurs 21 1-1/2 hours before sunrise Apr 17, hours LIBRA Apr 23 are plotted for lat. 34° N, where one hour after night of Saturn’s Wed 20 Alpha Lib these planets rise earlier in twilight, after sunset sunset Mon 18 rings in a darker sky, compared to the now 8° usual choice for our diagrams, T Antares Saturn from lat. 40° N. Viewing conditions are EAPOT tail S’most Tues 19 Gamma night of edgewise better from locations still farther Spica Vir Spica Moon Lyrid meteors SCORPIUS Tues 19 south of 34° N, and poorer from night and near peak, CORVUS farther north. For all locations, Mon 18 of closing night of Apr 22-23. Sunday 17 Full Moon binoculars are recommended for just past Full Wed until near perigee Antares fully enjoying what can be seen, 20 early and remain outdoors after your SSE S SSW SW WSW SE SE June. planet-viewing to enjoy the spring dawn chorus of birds! In May, the four planets Mercury- 1-1/2 hours Alpha Cap Wednesday 27, Thursday 28, Sat Apr 30, 35 min Venus-Mars-Jupiter will form Sunday April 24 Monday 25, Tuesday 26, Friday 29, 35 min several close pairs, two trios Venus crosses celestial before sunrise Beta 40 minutes 40 minutes 40 minutes 40 minutes before sunrise before sunrise (three planets within 5°), and a equator and begins to rise before sunrise before sunrise before sunrise before sunrise Venus ~ 14° from Moon. Venus 6° below Moon. quartet 6° across, all low in N of E, a little farther Me within 8° Me-Ve = 7°. Me-Ve = Me-Ve = 5°. Mercury, now Mercury 3.7° from Ve. eastern morning twilight. each morning. Mercury Mon 25 LL of Venus. Mars rising Ma-Me = 6°. Ma-Me = 6.5°. mag +1, is 4.4° Using binocs, try Tue 26 just past Moon and planets: The Moon, brightens from mag +1.6 Note: Morning 5.6° LL of Me. From FL, south TX FL, south TX, from Ve. apogee for Ju 7.5° one day past Full, appears S of to +0.9 this week, Last Qtr scenes rest of & HI, look for Ju HI, watch for Binocs show Moon LL of Me, Saturn on night of April 16. A closing from 9° to within week are for 2° LL of Ma. Jupiter 1.5° LL Ma 7° LL of Me and Ma Moon waning crescent Moon appears Delta lat 34° N. of Ma. and 1° UR of Ju. 0.5° N of Venus at dawn on April 30. 4° LL of Venus. Diagrams Cap, tail of Organizations hosting events showing Venus with other Sea-goat Venus Ve Ve above Ju. planets this week and Venus Ve for Astronomy Day May 7 or Mercury Ma Ve Me Astronomy Week May 2-8 or all of May are drawn SE E Ma E Me E Me E E Me E Me Ma Ma other events in April/May are for lat 34° N. Ma Ju Ju encouraged to reprint our May Sky Calendar and evening sky Robert C. Victor, Patti Toivonen $11.00 per year, starting anytime, from Sky Calendar, Abrams Planetarium, map for free distribution. ISSN 0733-6314 Subscription: Michigan State University, East Lansing, MI 48824 This chart is drawn for latitude 40° north, but April Evening Skies should be useful to stargazers throughout the continental United States. It represents the sky at © 2011 Abrams Planetarium the following local daylight times: Subscription: $11.00 per year, from Sky Calendar, Abrams Planetarium, Michigan State University, Late March 11 p.m. East Lansing, MI 48824-1324. Early April 10 p.m. Late April 9 p.m. This map is applicable one hour either side of the above times. NORTH Vega CASSIOPEIA LITTLE DIPPER LITTLE Polaris DIPPER Dbl Pleiades Capella Kids The - BIG BOOTES Hyades AURIGA TAURUS EAST Arcturus Castor Aldebaran OCl Overhead WEST + Pollux GEMINI The + LEO OCl VIRGO Sickle ORION Betelgeuse VIRGO Regulus + Nb ✷ Procyon Rigel Saturn Spica CANIS MINOR Sirius CORVUS CANIS MAJOR SOUTH The planet Saturn is plotted for mid-April 2011. At chart time 12 objects of first Nebula, a cloud of gas and dust out of which stars are forming, is marked (Nb) magnitude or brighter are visible. In order of brightness they are: Sirius, in that constellation. The open or galactic star cluster (OCl) known as the Arcturus, Vega, Capella, Rigel, Procyon, Saturn, Betelgeuse, Aldebaran, “Beehive” can be located between the Gemini twins and Leo. Coma Be- Spica, Pollux, and Regulus. In addition to stars, other objects that should be renices, “The Hair of Berenice,” is another open cluster (OCl), between Leo visible to the unaided eye are labeled on the map. The double star (Dbl) at and Bootes. Try to observe these objects with unaided eye and binoculars. the bend of the handle of the Big Dipper is easily detected. The famous Orion —D. David Batch.