Friday, January 31
After passing through its New phase last week, the Moon is now a thin waxing crescent some 8 percent lit by sunset this evening. You can find it setting in the southwest as soon as the Sun goes down, accompanied by Saturn (magnitude 1.1) and Venus (magnitude –4.7) above it.
Saturn sits just to the Moon’s upper left. Both are in Aquarius the Water-bearer; the Moon will close in on Saturn as time passes, moving to sit 1.1° due north of the ringed planet at midnight EST. This will be after the pair has set, however — they will sink below the horizon around 8 P.M. local time.
Venus is higher in the sky, standing near the Circlet of Pisces. It lingers longer after dark, setting nearly an hour later, just after 9 P.M. local time. If you have binoculars or a telescope at your disposal, you’ll want to swing them up toward this planet after dark. Invisible to the naked eye but well within reach of optics, magnitude 7.8 Neptune lies just over 3° southeast of Venus in Pisces. Look for a small, round, “flat” star with a grayish or bluish hue — that is the distant ice giant, spanning just 2” on the sky. Even with the crescent Moon above the horizon, its light shouldn’t interfere much with your attempts to see the solar system’s farthest planet.
Sunrise: 7:09 A.M.
Sunset: 5:19 P.M.
Moonrise: 8:35 A.M.
Moonset: 8:02 P.M.
Moon Phase: Waxing crescent (6%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 12 P.M. local time from the same location.
Saturday, February 1
Trekking quickly through the sky, the Moon passes 2° south of Venus at 3 P.M. EST and 1.4° north of Neptune at 6 P.M. EST. By sunset in the mid-U.S., the Moon appears to hang just to the lower left of Venus, with less than 2.5° between them. Our satellite now shows off a larger crescent than yesterday, with some 15 percent of its nearside directly lit by the Sun. This will make it a little harder to spot Neptune nearby with binoculars or a telescope, some 1.2° to the lower left of the Moon in the early-evening sky.
While you’ve got your optics out, look back toward blazing Venus and then continue 2.5° to the planet’s upper right (north). You will land on a crimson-colored star — that’s 19 Piscium, also called TX Piscium. This 5th-magnitude sun is a carbon star, meaning it possesses high quantities of carbon in its atmosphere, which results in its deep red color. It is also a variable star — its brightness swings somewhat irregularly between magnitudes 4.9 and 5.5, with a rough period of about 0.6 year, or 225 days.
Later this evening, the Moon reaches perigee, the closest point to Earth in its orbit, at 9:47 P.M. EST. Our satellite will then sit 228,327 miles (367,457 kilometers) away.
Sunrise: 7:08 A.M.
Sunset: 5:20 P.M.
Moonrise: 9:00 A.M.
Moonset: 9:16 P.M.
Moon Phase: Waxing crescent (13%)
Sunday, February 2
Early risers have some great options for observing this week, as the Moon sets in late evening and leaves the morning sky dark.
A few hours before sunrise, Leo the Lion remains high in the west, slowly making his way down toward the horizon. But the famous Leo Trio (or Leo Triplet) of galaxies we’re after today is located near the Lion’s hindquarters, giving us plenty of time to enjoy the sight before it gets too low.
The brightest star in Leo is magnitude 1.4 Regulus, marking the heart of the big cat and located in the southwestern portion of the constellation, closer to the horizon. On the other side of the star pattern is the tip of Leo’s tail, magnitude 2.1 Denebola. About 8.5° west of Denebola is magnitude 3.3 Chertan, and from here, it’s a short hop 2.5° southeast to the Leo Trio.
Best viewed with as large a scope as you’ve got, the Trio contains magnitude 9.3 M65 at its southwestern edge. This is a spiral galaxy with a bright core and fainter arms, though its structure can be challenging to see. Slightly brighter is magnitude 8.9 M66, also a spiral, some 0.3° southeast of M65.
Completing the triplet is NGC 3628, about 0.6° north of M66. Glowing at magnitude 9.5, it is the faintest of the three, presenting an edge-on view of its spiral shape that makes it look a bit like the Cigar Galaxy (M82) in Ursa Major. Like M82 and its nearby neighbor M81, astronomers believe that NGC 3628 recently (well, “cosmically” speaking, about 800 million years ago) underwent a gravitational encounter with M66.
Sunrise: 7:07 A.M.
Sunset: 5:21 P.M.
Moonrise: 9:24 A.M.
Moonset: 10:29 P.M.
Moon Phase: Waxing crescent (22%)
Monday, February 3
Venus now passes 4° north of Neptune at 3 P.M. EST. The pair is once again visible in the evening sky, hanging about 30° above the western horizon an hour after sunset.
Only Venus is visible to the naked eye — it’s the brightest point of light in the sky. With the Moon now far above the pair, Neptune should once again be easy to find with binoculars or a telescope, its magnitude of 7.8 far below the threshold of naked eyes. If you’re using binoculars, both Neptune and Venus should appear within the same field of view.
There’s a significant contrast between the two, as Neptune appears as a 2”-wide “dot” and Venus a 33”-wide crescent. The inner planet is now 36 percent lit and waning. If you’re able, return to it every few days to watch the crescent grow slimmer.
Sunrise: 7:06 A.M.
Sunset: 5:22 P.M.
Moonrise: 9:49 A.M.
Moonset: 11:44 P.M.
Moon Phase: Waxing crescent (32%)
Tuesday, February 4
Jupiter stands stationary against the stars of Taurus at 8 A.M. EST.
The planet is easy to find as soon as the sky grows dark, soaring some 65° high in the southeast an hour after sunset. Its bright magnitude –2.5 light gives Taurus a second “eye,” located above and slightly to the left of fainter magnitude 0.9 Aldebaran, the Bull’s alpha star.
Jupiter has dominated Taurus for months; tonight, it ends its retrograde (westward) motion and begins moving prograde (eastward) against the background stars, heading slowly back “out” toward the Bull’s horns.
Also highly visible in the evening sky is magnitude –1.1 Mars, located to Jupiter’s lower left in Gemini the Twins. Of the two stars that make up the Twins’ heads, Mars is closer to (and currently side by side with) magnitude 1.2 Pollux, while slightly fainter (magnitude 1.6) Castor shines above and to the left of the Red Planet.
Sunrise: 7:05 A.M.
Sunset: 5:23 P.M.
Moonrise: 10:16 A.M.
Moonset: —
Moon Phase: Waxing crescent (43%)
Wednesday, February 5
First Quarter Moon occurs at 3:02 A.M. EST. Nearly half a day later, the Moon passes 5° north of Uranus at 4 P.M. EST, located at the border between Aries and Taurus.
But our attention is definitely back in Taurus tonight, as the Moon occults the Pleiades (M45) star cluster overnight. Observers in the western U.S. will get to see the entire event, while those in the eastern portion of the country will see the Pleiades set with the Moon in the middle of the cluster.
You’ll want to keep an eye on the Moon and the Pleiades as the hours tick by this evening and the two objects sink in the west. For those in the Midwest, the first star — magnitude 3.7 Electra — disappears behind the darkened western limb of the Moon 1:21 A.M. CST from Kansas City. You’ll need a clear western horizon or an elevated observing spot from the Midwest, too — this occurs with the Moon and cluster only 10° high.
The next star, magnitude 4.1 Merope, disappears from the sky above Kansas City at 1:57 A.M. CST. The Moon is now just 4° above the horizon. Those farther west see more occultations, including magnitude 2.9 Alcyone around 1:23 A.M. MST from Denver and and magnitude 3.6 Atlas at 2:08 A.M. MST from Salt Lake City.
The number of occultations you’ll see and their timing depends on your location. Check out Robert Sandy’s 2025 bight star occultation listings to get details for your location (or the city closest to you). Note that all dates and times are given in Universal Time and will need to be converted to local time.
Sunrise: 7:04 A.M.
Sunset: 5:25 P.M.
Moonrise: 10:49 A.M.
Moonset: 12:59 A.M.
Moon Phase: Waxing gibbous (55%)
Thursday, February 6
After an early-morning occultation of the Pleiades, the Moon moves on and passes 5° north of Jupiter in Taurus at 11 P.M. EST. It’s a lovely pairing that astrophotographers won’t want to miss, with the gibbous Moon hanging to the upper left of bright Jupiter.
Also in the evening sky, the Big Dipper is climbing in the northeast as darkness falls, circling around Polaris, the North Star — the only star in our sky that does not move. By 9 P.M. local time, the Big Dipper appears to stand on the end of its handle, a star called Alkaid. The next star in, where the handle “kinks,” is actually two stars: Alcor and Mizar. Mizar is the brighter, more obvious star — it’s magnitude 2.3. But Alcor is magnitude 4 — also within the limits of the naked eye. It sits roughly 12’ northeast of Mizar, appearing to Mizar’s lower left as the Big Dipper is standing up like this.
Can you see both stars without optical aid? If you’re having trouble, wait for the Dipper to rise (and rotate) a little more, bringing the end of the handle farther from the horizon. Alternatively, try looking away from the stars, keeping them in your peripheral vision. This might help to bring out dimmer Alcor against the background sky.
If you look at the pair with a telescope, you’ll see that Mizar itself splits into a double star, with components some 14” apart.
Sunrise: 7:03 A.M.
Sunset: 5:26 P.M.
Moonrise: 11:29 A.M.
Moonset: 2:14 A.M.
Moon Phase: Waxing gibbous (66%)
Friday, February 7
With the Moon still setting early and leaving a window of darkness before dawn, let’s observe one of the most famous globular clusters in the sky: M13, which lies near the Keystone asterism in Hercules. This constellation sits to the upper right of the bright, magnitude 0 star Vega in Lyra as these stars sit high in the east around 5 A.M. local time this morning.
The Keystone is made up of four stars: As it appears in the sky this morning, the lower lefthand corner is magnitude 3.2 Pi (π) Herculis. Moving clockwise, magnitude 3.5 Eta (η) Herculis sits above Pi, magnitude 2.8 Zeta (ζ) Herculis to Eta’s lower right, and magnitude 3.9 Epsilon (ε) Herculis forms the Keystone’s lower righthand corner.
Focus on the top of the Keystone — Eta and Zeta — and draw a line between these two stars. About one-third of the way from Eta to Zeta (so, starting at the former and heading toward the latter) is M13. This 6th-magnitude globular can just be seen without optical aid under good conditions, and pops out well with any instrument. A telescope will show a dense core with scattered stars around the edges. Even a 3-inch scope will show plenty of detail, as M13 spans about 20’. Higher powers and larger scopes may show the cluster’s Y-shaped “propeller,” formed from three intersecting dust lanes where fewer stars are visible.
Sunrise: 7:02 A.M.
Sunset: 5:27 P.M.
Moonrise: 12:18 P.M.
Moonset: 3:27 A.M.
Moon Phase: Waxing gibbous (76%)
Sky This Week is brought to you in part by Celestron.
