Sunday, February 20
Comet 19P/Borrelly, currently observed around magnitude 9.5 and slowly fading, appears to pass close to Uranus in the night sky today. Both are sinking in the west this evening after sunset, situated in the southern portion of Aries.
Although the Ram covers 441 square degrees on the sky, its three brightest stars are all clumped together in the northwestern portion of its real estate. These are Hamal (magnitude 2), Sheratan (magnitude 2.6), and Mesarthim (magnitude 3.9). Tonight, Borrelly sits 6° east-southeast of the last and faintest of the three, while Uranus is another 5° southeast of Borrelly. The planet’s dim magnitude 5.8 glow is just bright enough to pick up with the unaided eye under excellent conditions; binoculars or a telescope will easily show its 3"-wide disk, while binoculars’ wide field of view should also net you the planet and comet together.
Uranus now sits just 0.5° from the 6th-magnitude star 29 Arietis; the planet will move slightly northeast in the coming days, ending the month 43' from this star.
Sunrise: 6:46 A.M.
Sunset: 5:42 P.M.
Moonrise: 10:08 P.M.
Moonset: 8:58 A.M.
Moon Phase: Waning gibbous (83%)
Monday, February 21
An hour after sunset, the gorgeous open cluster M44 in Cancer already floats more than 35° high. As the darkness deepens, this glittering group of stars may emerge from the background as a 4th-magnitude fuzz.
This easy naked-eye object spans some 95' and is also known as the Beehive Cluster or Praesepe the Manger. Because it requires no optical aid to spot, it has been known since ancient times and records of it date back to at least 260 B.C. But it doesn’t truly resolve until you point binoculars or a telescope its way, which will show at least several dozen of its 350 stars.
The Beehive is some 580 light-years away and roughly 730 million years old. Researchers think it may have once been associated with the Hyades over in Taurus — perhaps both were birthed in a single giant molecular cloud and moved apart over time.
Sunrise: 6:45 A.M.
Sunset: 5:43 P.M.
Moonrise: 11:18 P.M.
Moonset: 9:24 A.M.
Moon Phase: Waning gibbous (75%)
Tuesday, February 22
Leo the Lion is now rising in the east as the Sun sinks below the horizon. As this great cat climbs the sky, you’ll easily pick out his brightest star, magnitude 1.4 Regulus. Some 150 times brighter than our Sun, this star shines at us from a mere 79 light-years away.
Regulus also marks the base of a well-known asterism called the Sickle of Leo, which looks a bit like a large backwards question mark on the sky. To trace out this figure, move from Regulus about 5° due north to Eta (η) Leonis, the top of the Sickle’s handle. Then, move clockwise to connect Gamma (γ), Zeta (ζ), Mu (μ), and Epsilon (ϵ) Leonis. This asterism also outlines Leo’s head, which faces west on the sky as the Lion appears to sit in profile.
Sunrise: 6:43 A.M.
Sunset: 5:44 P.M.
Moonrise: —
Moonset: 9:53 A.M.
Moon Phase: Waning gibbous (63%)
Wednesday, February 23
Last Quarter Moon occurs at 5:32 P.M. EST. Rising half an hour after midnight, you’ll find our satellite floating at the border of Libra and Scorpius, sitting some 5° northwest of the Scorpion’s claws. A few hours later, the rest of the arachnid’s body has risen, and you can follow a line traveling southeast from the Moon through Delta (δ) and Pi (π) Scorpii to the bright red 1st-magnitude luminary Antares, often depicted as the heart of the Scorpion. Less than 1.5° to Antares’ west is the globular cluster M4, just at the edge of naked-eye visibility at magnitude 5.6 and best viewed with binoculars or a telescope, particularly with the still-lit Moon nearby.
Keep skimming southeast to see Scorpius’ long, curving tail, tipped by bright Shaula and Lesath, which form its stinger. To these stars’ upper left (northeast) are two open clusters of stars: 3rd-magnitude M7, 4.6° east-northeast of the stinger; and 4th-magnutude M6, 5° north-northeast of it. Both are visible with the naked eye under good conditions and can be seen easily with binoculars or any small scope.
Sunrise: 6:42 A.M.
Sunset: 5:45 P.M.
Moonrise: 12:30 A.M.
Moonset: 10:28 A.M.
Moon Phase: Waning gibbous (52%)
Thursday February 24
Following its conjunction with the Sun earlier this month, Saturn is now peeking out from the dawn twilight. Rising roughly half an hour before the Sun, the ringed planet glows at magnitude 0.8 and shares western Capricornus with Mercury, now magnitude 0. By 20 minutes before sunrise, Saturn is just 3° high in the brightening sky, while Mercury is twice that, easier to spot from where it’s sitting to Saturn’s upper right.
Farther west along the ecliptic, you won’t be able to miss Venus and Mars, both in Sagittarius. Venus is the brightest object you’ll see in the sky at magnitude –4.8, just starting to fade from its greatest brilliancy earlier this month. Meanwhile, the Red Planet is fainter than all the rest, shining gently at magnitude 1.3 about 5.5° south of Venus. These two planets rise much earlier — around 4:30 A.M. local time — so you can catch them in a darker sky to also enjoy the rich background of stars and dust they’re currently traveling through.
Sunrise: 6:40 A.M.
Sunset: 5:47 P.M.
Moonrise: 1:44 A.M.
Moonset: 11:11 A.M.
Moon Phase: Waning crescent (41%)
