By Mark Wagner
Mark Wagner brings us highlights of what's happening in the sky each night this week. Click on each image to enlarge the view. Happy gazing!
Friday, March 31
53 Ophiuchi is an easy target for those who enjoy splitting double stars in binoculars. If you have a 10X binocular, and especially if you have them on a nice parallelogram mount, this is a quick and fun endeavor for a short astronomy session. The binoculars come in handy for lots of targets! Find 53 Ophiuchi high in the highlighted triangle capped by (A) Alpha Ophiuchi, Rasalhague. The primary member of this pair is at magnitude 5.8, showing easily. Its secondary member is the challenge at magnitude 7.5. Both are white, and separated by a binocular friendly 41.3".
Skill Level: Beginner
Suggested Gear: Orion 10x50 Binocular Stargazing Kit II, Orion 15x70 Astronomical Binocular & HD-F2 Tripod Bundle
Tomorrow Evening: Moon Targets
Saturday, April 1
Tonight's Moon is getting fat, and far. At 90.8% illumination and waxing gibbous, it is nearing apogee. Use your 10X binoculars to find the walled plain (1) Schickard on the southern limb. At 137 miles diameter it's an easy target. A 50mm instrument shows off brilliant crater (2) Aristarchus, with such a high albedo it shows up easily in earthshine. Look for high terraced walls and a small central mountain. Next to Aristarchus is amazing (3) Vallis Schroteri, an almost 100 mile long arching rille, a lunar favorite! Challenge yourself with 300mm with 151 mile long (4) Rima Marius, a sinuous rille running east-west then bending north-south.
Skill Level: Beginner
Suggested Gear: Orion StarBlast 102mm Altazimuth Travel Refractor Telescope, Orion SkyLine 12" Dobsonian Reflector Telescope
Tomorrow Morning: M107 in Ophiuchus
Sunday, April 2
M107 is a very loose globular cluster in southern Ophiuchus, first discovered by Charles Messier's contemporary Pierre Méchain in April 1782. It is moderate sized at 10 arc-minutes and in the general range of its type of object at 20,000 light years. It appears dimmer than is apparent magnitude of 7.9, due to its loose nature. John Herschel described M107 as "globular cluster of stars, large, very rich, very much compressed, round, well resolved, clearly consisting of stars". You can find it about 2-1/2 degrees south and a bit west of (Z) Zeta Ophiuchi.
Skill Level: Beginner
Suggested Gear: Orion SkyLine 8" Dobsonian Reflector Telescope, Orion SkyLine 12" Dobsonian Reflector Telescope
Tomorrow Evening: Big Moon Targets
Monday, April 3
With the Moon tonight at 99% illumination these are interesting "Big Moon" targets: A 10X binocular shows walled plain (1) Eddington near the Terminator, 81 miles diameter, filled with dark lava, flat and wrecked. A 50mm instrument for 30 mile diameter 7,000 foot tall crater (2) Cardanus reveals high terraced walls and a small central mountain. Use 200mm to view Catena Krafft, a 36 mile long crater chain connecting craters Cardanus and Krafft to its north. With 300mm Rima Cardanus is possible, a rille in the arena of Crater Cardanus running 73 miles southwest-northeast.
Skill Level: Beginner
Suggested Gear: Orion 10x50 Binocular Stargazing Kit II, Orion SkyLine 12" Dobsonian Reflector Telescope
Tomorrow Evening: Full Moon
Tuesday, April 4
Welcome the first Full Moon of our new season, spring in the north, fall in the south. Luna is in Virgo, between alpha star Spica and gamma star Porrima, a fine double. The Earth's shadow is outlined here, delineating where an eclipse would occur. Native America tribes called this full moon the Pink Moon, as the flower Phlox commonly bloomed in April. It was also referred to as the Egg Moon, Full Sprouting Grass Moon and Full Fish Moon.
Skill Level: Beginner
Suggested Gear: Lawnchair and naked eyes, no equipment needed
Tomorrow Evening: Constellation Hydra
Wednesday, April 5
The constellation Hydra is a monster, both figuratively and literally. The largest of our 88 constellations in area, at 1303 square degrees, and in length spanning 100 degrees, it represents the mythological combination of a snake, lion and bird. It is also associated with the hero Hercules' labors. The (A) alpha star is Alphard, a magnitude 2.0 orange giant. Neighbor constellations include (1) Sextans, (2) Crater, (3) Corvus, (4) Virgo, (5) Libra, (6) Lupus, (7) Centaurus, (8) Antlia, (9) Pyxis, (10) Puppis, (11) Monoceros, (12) Canis Major, (13) Cancer and (14) Leo.
Skill Level: Beginner
Suggested Gear: Orion 2x54 Ultra Wide Angle Binoculars, Orion SkyLine Deluxe Green Laser Pointer
Tomorrow Morning: Moon Targets
Thursday, April 6
This morning's Moon is two days past full, and 98.4% illuminated as waning gibbous. A 10X binocular for crater (1) Petavius shows the 107 mile diameter form on the border of Mare Fecunditatis, with steep and tormented slopes. A 50mm instrument for nearby crater (2) Legendre reveals a 48 mile diameter feature on the limb, isolated with steep slopes and three rim craterlets. The southeast slope of Petavius features (3) Vallis Palitzsch, a southwest to northeast alignment of three craters. 200mm shows (4) Rima Hase to the south, a 182 mile long rille connecting Hase D to Marinus.
Skill Level: Beginner
Suggested Gear: Orion 10x50 WA Binoculars, Orion SkyLine 8" Dobsonian Reflector Telescope
Carbon Star V Hydrae
Friday, April 7
V Hydrae is an excellent carbon and variable star easily found close to two bright constellation figure stars, (N) Nu Hydrae and (A) Alpha Crateris (Alpha Hydrae also labeled). The inset shows V Hya a short distance below a solitary magnitude 5.2 star. A long period variable over 530.7 days from magnitude 6.0 to 12.3, it is currently two months from dimmest at midpoint, so should be quite red if you can identify it. Late summer you can return to see its gradual brightening.
Skill Level: Beginner
Suggested Gear: Orion SpaceProbe 130ST Equatorial Reflector Telescope, Orion SkyLine 6" Dobsonian Reflector Telescope
Tomorrow Morning: Moon Targets
Saturday, April 8
This morning's Moon is waning gibbous and 88.9% illuminated. Use a 10X Binoculars to view 62 mile diameter walled plain (1) Gartner's flat lava filled floor north of Mare Frigoris. A 50mm instrument shows crater (2) Macrobius on the Terminator, with very high terraced walls and central mountain within its 39 mile diameter. The volcanic dome (3) Cauchy Tau is easy in 100mm south of Rupes Cauchy. Using 200mm the fine Y shaped system of rilles (3) Rimae Atlas are contained in Crater Atlas' arena.
Skill Level: Beginner
Suggested Gear: Orion 10x50 Binocular Stargazing Kit II, Orion SkyQuest XT8 Classic Dobsonian Telescope
Tomorrow Evening: Ghost of Jupiter
Sunday, April 9
NGC 3242 is a fine bright planetary nebula along the stick figure of Hydra. Find it easily hopping from (A) alpha to (U) Upsilon, (L) Lambda to (M) Mu, and scanning just under two degrees slightly east of south. Bertrand Laville's excellent sketch in a large aperture Dobsonian shows the fine detail seen on excellent nights. The planetary is known as the Ghost of Jupiter, and the Eye Nebula. It sits at approximately 4800 light years, shining at magnitude 8.60 with an apparent size of 25 arc-seconds. This is a target for any size telescope.
Skill Level: Beginner
Suggested Gear: Orion SkyQuest XT10 Classic Dobsonian Telescope, Orion SkyLine 12" Dobsonian Reflector Telescope
Tomorrow Evening: Venus Meets Pleiades, Mercury High
Monday, April 10
Tonight you can grab a quick and rewarding view of Venus parallel to The Pleiades star cluster, easy to see over the western horizon an hour after sunset. Venus is a blaring beacon at -4.06 magnitude, it is a jewel set on the famous Seven Sisters cluster. And, adding to the visual treat, fleet Mercury sits below them both tonight, at is highest and greatest elongation.
Skill Level: Beginner
Suggested Gear: Lawnchair and naked eyes, no equipment needed
Tomorrow Morning: Moon Targets
Tuesday, April 11
Our 60.3% illuminated Moon is at 21.76 days waxing gibbous, heading toward perigee. The great walled plain Ptolemaeus is perfect for 10X binoculars, showing of its large round flat floor and 93 mile diameter high walls. A 50mm instrument for 24 mile diameter crater (2) Autolycus shows its very high terraced walls, central mountain and rough floor. Nearby for 100mm is (3) Vallis Alpes, the alpine valley, a fault bordered by high cliffs running 79 miles with a difficult to view rille along its floor. Bordering the Montes Apenninus is (4) Rima Hadley, a beautiful twisting 48 mile long rille requiring 200mm, worth the visit!
Skill Level: Beginner
Suggested Gear: Orion 10x50 Binocular Stargazing Kit II, Orion SkyLine 8" Dobsonian Reflector Telescope
Tomorrow Evening: Messier 68 in Hydra
Wednesday, April 12
Messier 68 is in far eastern Hydra, easily located drawing a line from (D) Delta to (B)Beta Corvi and continuing south approximately 1/3rd that distance. One of the more remote of the Messier class globular clusters, it is 33,000 light years distant, glowing at magnitude 7.7 over 12 arc-minutes apparent size. The distance makes resolving individual stars difficult in smaller telescopes. Steve Gottlieb notes in an 8" Dobsonian "few stars resolved across disk." William Herschel wrote "stars are blended together; chiefly round, there are very few scattered stars about."
Skill Level: Beginner
Suggested Gear: Orion SkyLine 10" Dobsonian Reflector Telescope, Orion SkyLine 12" Dobsonian Reflector Telescope
Tomorrow Morning: Moon Targets
Thursday, April 13
At 23.76 days old the Moon is a 37.6% illuminated waning crescent. Use a 10X binocular for the walled plain (1) Longomontanus, a circular 88 mile diameter southern feature. Containing high but damaged terraced walls, see its large flat floor with small central mountains. 50mm instruments for views of crater (2) Copernicus show an octagonal shape of 56 miles, very steep slopes, high terraces walls and three central mountains. (3) Stadius T, always a favorite for 100mm views, shows a north-south chain of numerous small overlapping craterlets, superb in steady seeing. With 200mm (4) Rima Hesiodus, a rectilinear rille running 182 miles southwest to northeast.
Skill Level: Beginner
Suggested Gear: Orion Resolux 10x50 Waterproof Astronomy Binoculars, Orion SkyQuest XT8 Classic Dobsonian Telescope Kit
Tomorrow Evening: Double Star in Hydra
Charts from Starry Night Pro. M107 sketch by Miguel Ángel Pugnaire Sáez. NGC 3242 sketch by Bertrand Laville. M68 sketch by Martijn Straub. Lunar images from NASA LRO, Other images from Virtual Moon Atlas and Starry Night Pro.
Mark Wagner is a lifelong astronomy enthusiast and deep sky observer in the San Francisco bay area. Visit our Facebook Page if you'd like to post comments, questions, sketches or images you've taken to our Night Sky Tonight post.