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The Night Sky of February

Dr. Wayne Wooten
Professor of Astronomy

For February, the Moon is first quarter on February 1st, and the Full Moon, the Hunger Moon, is on February 9th. The last quarter moon is on February 15th, and the waning crescent passes in front of Mars on February 18th; the occultation starts exactly at sunrise, about 7:20 a.m. CST, and ends in daytime at 8:38 a.m. The moon will pass just below Jupiter the next morning. The new moon is on February 23. The waxing crescent moon passes six degrees south of Venus in the evening sky on February 27th.

Mercury peaks out in evening twilight in early February, reaching greatest eastern elongation of 18 degrees from Sun on February 10th. Venus dominates the evening, appearing mag. -4.1 and 73% sunlit, with a disk 15" across on February 1st. Venus reaches greatest elongation, 47 degrees east of the Sun, on February 24th, and appears exactly half lit in our scopes, and now closer to us, 18" across now and up to mag. -4.4. After this, she will appear as a crescent in telescopes until she overtakes us at inferior conjunction in early June, moving into the dawn sky for the rest of 2020. Mars is in the dawn sky, and will be occulted by the moon on the morning of February 18th. Mars will be at its best at opposition in October 2020. Jupiter lies farther east of Mars, and Saturn is low in the dawn twilight, coming out of the Sun’s glare in February.

While the naked eye, dark adapted by several minutes away from any bright lights, is a wonderful instrument to stare up into deep space, far beyond our own Milky Way, binoculars are better for spotting specific deep sky objects. For a detailed map of northern hemisphere skies, about January 31st, visit the www.skymaps.com website and download the map for February; it will have a more extensive calendar, and list of best objects for the naked eyes, binoculars, and scopes on the back of the map.

The constellation Cassiopeia makes a striking W in the NW. She contains many nice star clusters for binocular users in her outer arm of our Milky Way, extending to the NE now.

Cassiopeia’s daughter, Andromeda, starts with the NE corner star of Pegasus’’ Square, and goes NE with two more bright stars in a row. It is from the middle star, beta Andromeda, that we precede about a quarter the way to the top star in the W of Cassiopeia, and look for a faint blur with the naked eye. M-31, the Andromeda Galaxy, is the most distant object visible with the naked eye, about 2.5 million light years away.

Overhead is Andromeda’s hero, Perseus. Between him and Cassiopeia is the fine Double Cluster, faintly visible with the naked eye and two fine binocular objects in the same field. Perseus contains the famed eclipsing binary star Algol, where the Arabs imagined the eye of the gorgon Medusa would lie. It fades to a third its normal brightness for six out of every 70 hours, as a larger but cooler orange giant covers about 80% of the smaller but hotter and thus brighter companion as seen from Earth.

At Perseus’ feet for the famed Pleiades cluster; they lie about 400 light years distant, and over 250 stars are members of this fine group. East of the seven sisters is the V of stars marking the face of Taurus the Bull, with bright orange Aldebaran as his eye; use it (mag. +0.9) as a comparison star to measure the fading of Betelguese. The V of stars is the Hyades cluster, older than the blue Pleiades, but about half their distance.

Yellow Capella, a giant star the same temperature and color as our much smaller Sun, dominates the overhead sky. It is part of the pentagon on stars making up Auriga, the Charioteer (think Ben Hur). Several nice binocular Messier open clusters are found in the winter milky way here. East of Auriga, the twins, Castor and Pollux highlight the Gemini; they were the first two recruits for the Argonauts, UWF fans! Congrats!!!

South of Gemini, Orion is the most familiar winter constellation, dominating the eastern sky at dusk. The reddish supergiant Betelguese marks his eastern shoulder, while blue-white supergiant Rigel stands opposite on his west knee. Betelguese is also known as alpha Orionis, for it has been the brightest star in Orion most of the time. But in the last few months, this red giant has grown redder and fainter even to naked eye observers. It was near normal, mag 0.3 in October, but by February has faded a full magnitude down to mag. 1.3, or 2.5X fainter than five months ago. This is the faintest observation in record so far! It is a pulsating irregular variable, as small as the orbit of Mars when smallest, hottest, and brightest, but as big as Jupiter’s orbit when coolest, forming a smoke cloud of carbon soot around it for now. This instability makes many believe it is s potential supernova, with a core collapse creating an explosion brighter than the Full moon for us viewing it from a safe 700 light years distance. This photo of Orion shows Betelguese near its maximum brightness back in 1984.

Just south of the belt, hanging like a sword downward, is M-42, the Great Nebula of Orion, an outstanding binocular and telescopic stellar nursery. The bright diamond of four stars that light it up are the trapezium cluster, one of the finest sights in a telescope. Just east of Betelguese is the fine binocular cluster NGC 2244. But the much fainter Rosette Nebula that it lies in the center of requires bigger scopes or astrophotography.

In the east rise the hunter’s two faithful companions, Canis major and minor. Procyon is the bright star in the little dog, and rises before Sirius, the brightest star in the sky. Midway between them is the fine Rosette Nebula, a star nursery of gas and dust including the nice open cluster NGC 2244, easily found in binoculars. Several other nice clusters for binoculars are also plotted on your February sky map printout, be sure to check them out some clear, crisp winter evening.

Sirius dominates the SE sky by 7 p.m., and as it rises, the turbulent winter air causes it to sparkle with shafts of spectral fire. Beautiful as the twinkling appears to the naked eye, for astronomers this means the image is blurry; only in space can we truly see "clearly now". At 8 light years distance, Sirius is the closest star we can easily see with the naked eye.

When Sirius is highest, along our southern horizon look for the second brightest star, Canopus, getting just above the horizon and sparkling like an exquisite diamond as the turbulent winter air twists and turns this shaft of starlight, after a trip of about 200 years!

To the northeast, a reminder that spring is coming; look for the bowl of the Big Dipper to rise, with the top two stars, the pointers, giving you a line to find Polaris, the Pole Star. But if you take the pointers south, you are guided instead to the head of Leo the Lion rising in the east, looking much like the profile of the famed Sphinx. The bright star at the Lion’s heart is Regulus, the "regal star". Fitting for our cosmic king of beasts, whose rising at the end of this month means March indeed will be coming in "like a lion".

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