Skylights: February 2023

February 2023  :  Jim Hendrickson

The mid-winter sky has much to offer during the shortest month of the year. Early evening observers can now observe the stellar and deep-sky delights residing within the constellations of the Winter Hexagon, which is bisected by the outer arms of the Milky Way. Although not as easily visible to the unaided eye as the summer Milky Way, this region of the galaxy contains some of the sky’s best destinations for small telescopes and binoculars, including the Great Orion Nebula.

February’s sky also shows us the beginnings of the transitions to spring. Over the course of the month, we have 70 extra minutes of sunlight, and as a consequence, 63 fewer minutes of astronomical darkness at the end of the month as compared to the beginning. 

After twilight fades, one of autumn’s most recognizable asterisms, the Great Square of Pegasus, has turned to form a diamond, and is sinking into the west. The last holdouts of summer, Vega and Deneb, are finally leaving our northwestern sky. 

Over in the northeast, Ursa Major is standing on its tail, ready to roar its way into spring, and in the east, Leo and Virgo are coming into view. With Leo, Virgo, and Coma Berenices culminating high in the south just after midnight, we are entering the best time of year to explore with a telescope the great Realm of the Galaxies beyond, located throughout these spring constellations. This is also the time of year to begin planning and practicing for the annual Messier Marathon, a March all-nighter during which all 110 objects in Messier’s catalog of deep sky objects can be observed, under ideal conditions.

While many of the planets are appearing to move towards the far side of the Sun from our view, there is still much to see in the solar system in February

Perhaps you might be able to spot Saturn low in the west-southwestern sky after sunset at the beginning of February, but it will be lost in twilight through the rest of the month as it reaches conjunction on the 16th. Saturn crosses the border from Capricornus into Aquarius on the 13th, followed by the Sun on the 16th, the same day Saturn is in conjunction.

Venus is the most prominent planet visible in the evening sky in February. The brilliant “evening star” sets 2 hours after the Sun at the beginning of the month, and 2.5 hours after sunset at the end of the month. Following Venus each night in February, you will notice it closing distance with Jupiter by about 1° per night. The two planets are at their closest on March 1, when they will be separated by just 0.5°. But before that, Venus has a conjunction with Neptune on the 15th, when Venus will appear 0.5° east of Neptune.

Venus crosses into Cetus on the 26th, then into Aquarius on the 27th. At the end of February, Venus is just over 1° west of Jupiter.

Jupiter crosses into Cetus on the 5th, and remains within the boundaries of the non-zodiacal whale through the 18th. Having dominated the evening sky just a few weeks ago, Jupiter now appears lower each evening, and will soon be out of view. 

Mars continues to move eastward through Taurus in February. On the 11th-12th, it crosses back into the Winter Hexagon, through the Aldebaran-Capella segment. Fading slowly but still shining at magnitude 0, the Red Planet is now showing a distinct gibbous phase in a telescope, as its globe shrinks from 10.6 to 8.3 arcseconds through the month, due to the increasing distance between Earth and Mars. On February 14, that distance will be 1 AU.

Mercury, the only planet visible in the morning sky, is in good position to be observed during the first half of February, after which it moves south of the ecliptic while closing angular distance to the Sun, leaving it difficult to spot low in twilight before sunrise. The 27.5 day crescent Moon is 7° to the right of Mercury on the 18th.

Watch the waxing gibbous Moon just after twilight on the 3rd, as it will be aligned with Pollux & Castor in Gemini. The Moon will appear just 2.9° southeast of Pollux. The Moon passes 3° north of M44 on the 4th, and the Full Snow Moon occurs on the 5th. On the 6th, the Moon rises 4.1° northeast of Regulus in Leo.

On the 11th, the Moon is 2.4° northeast of Spica, in Virgo, and last quarter occurs on the 13th.

On February 21st, a stunning alignment of the 1.9-day crescent Moon, Venus, and Jupiter occurs in the western sky after sunset. Additionally, Neptune is just 2.4° to the right of the Moon. On the following night, the Moon appears just 1.2° south of Jupiter.

New Moon occurs on the 20th. The Moon passes 3.6° E of M45 on the 26th, is first quarter early on the 27th, and passes 0.3° north of Mars after midnight on the 28th.

Uranus, in Aries, reaches its eastern quadrature on the 3rd. This means that it is near the meridian at sunset, and sets just after midnight. While bright Moonlight will make it challenging to observe with binoculars this week, there aren’t too many weeks left to try to spot it before it is too low in the sky.

Neptune, located about 14° west of Jupiter near the border of Aquarius and Pisces, is fairly low in the sky all month. It is worth looking for Neptune, however, when Venus is just 0.6° away on the 14th and 15th. 

Asteroid 2 Pallas shines at magnitude 7.7 in Canis Major. It is slowly moving northward, and passes between Xi1 and Xi2 CMa on the 7th-8th. During the final week of the month, it can be found near Sirius, coming within 2.1° to the west-northwest of our night sky’s brightest star on the 26th. Binoculars or a small telescope can be used to track the magnitude 7.7 asteroid, which will be about 1.5 AU away from Earth when it passes near Sirius.

Dwarf planet Ceres, in Virgo, rises at about 8:00pm at mid-month, and is high enough to observe at midnight. The 7.5 magnitude object should be relatively easy to track in a region of sky sparsely populated by dim stars. It can be found within a binocular field west of Vindemiatrix (epsilon Virginis). Ceres reaches its stationary point on the 4th, and begins its retrograde loop through the Realm of the Galaxies. 

Comet C/2022 E3 (ZTF) is closest to Earth (0.284 AU) on the 1st. The comet begins the month moving rapidly southward through Camelopardalis into Auriga, and appears just over 1° from Capella on the 5th. On the 10th and 11th, it passes Mars, being within 1.5° of the planet during these evenings. It is near Aldebaran on the 14th, then skirts its way along the western side of Orion’s sword through the remainder of the month. Although bright moonlight may interfere with observations when it is at its closest early in the month, it should remain visible in binoculars under a reasonably dark sky for much of the month. A small telescope will be best to observe it though, especially when it passes by Capella, Mars, and Aldebaran.