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The Sky This Week, 2017 February 14 - 21

Rosettes are red...
The Rosette Nebula, NGC 2237 in Monoceros, imaged 2015 February 14
with an 80mm (3.1-inch) f/6 Antares Sentinel refractor
and a Canon EOS Rebel T2i DSLR

The Moon swings into the morning sky this week, drifting from the rising springtime stars and ending the week with the pre-dawn summer constellations. Last Quarter occurs on the 18th at 2:33 pm Eastern Standard Time. Early risers can see a nice grouping of the Moon, Jupiter, and the bright star Spica before sunrise on the morning of the 15th. On the mornings of the 20th and 21st look for Luna in the southeastern sky near the yellow-tinted planet Saturn.

The bright stars of the Great Winter Circle are prominently featured in the early evening sky. The familiar figure of Orion the Hunter crosses the meridian at 8:00 pm EST, surrounded by many other prominent star patterns. By using the Hunter’s three "belt" stars, you can find your way around five other constellations. If you follow a line through the belt stars to the northwest you’ll encounter the bright amber-hued star Aldebaran, the lead star of Taurus, the Bull. Surrounding Aldebaran is a V-shaped aggregation of third-magnitude and fainter stars that make up the Hyades star cluster. This group of stars is one of the closest galactic clusters to the solar system, about 150 light-years away. Aldebaran itself is not a cluster member, being about half as far away. They Hyades and the nearby Pleiades are wonderful targets for binoculars from dark-sky sites. Moving back to Orion’s belt, extending a line to the southeast will bring you to Sirius, the brightest star in the sky. Sirius is a dazzling sight in binoculars with an icy blue-white glimmer that contrasts nicely with Aldebaran and ruddy Betelgeuse in Orion. It leads Canis Major, one of Orion’s hunting dogs, across the sky behind its master. From a dark sky you’ll see the faint glow of the winter Milky Way rising from above Sirius, passing just east of Orion. Buried in these star clouds id the faint constellation of Monoceros, the Unicorn, whose brightest star is just above fourth magnitude. What it lacks in stars is more than made up for by the star clusters and gaseous nebulae that can be seen in binoculars of small telescopes. You can follow the Milky Way up past the bright star Procyon, then through the "feet" of the Gemini twins, ultimately winding up in the pentagon-shaped constellation of Auriga, the Charioteer. For the naked eye, nine of the 25 brightest stars in the sky can be found in these constellations in addition to the dozens of deep-sky objects brought to light with modest optical aid. It remains one of my favorite parts of the sky to haunt.

Brilliant Venus is now beginning to lose ground on both the nearby planet Mars and the ever-persistent Sun. She now sets a little bit earlier each night as she begins to move toward inferior conjunction, when she passes between Earth and the Sun. She will remain prominent for the next few weeks, but a month from now she will seem to fall from the sky like a stone.

Mars continues to move eastward along the ecliptic, drifting through the faint starfields of Pisces. The red planet is also gradually losing ground to the encroaching Sun, but unlike Venus he’ll remain visible in the post twilight sky until mid-May.

You’ll now find Jupiter rising in the late evening. By the 18th he crests the eastern horizon at around 10:00 pm EST. Look for him near the rising Moon before midnight on the evenings of the 14th and 15th. In the pre-dawn hours of the 15th he entertains the Moon and the bright star Spica. Your best telescopic view of him will still be between 3:00 am and dawn.

Saturn wallows in the far southerly declination of the ecliptic. As morning twilight gathers you’ll find him low in the southeast some 15 degrees east of the ruddy star Antares in the constellation of Scorpius. The telescope will reveal the planet’s unmistakable rings, but sharp detail will be thwarted by his low altitude above the horizon.


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