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The Sky This Week, 2019 January 29 - February 5

Stellar gems in the winter Milky Way
NGC2244, the Rosette Nebula, imaged 2015 February 14 from Morattico, Virginia
NGC2244, the Rosette Nebula.
imaged on 2015 February 14 from Morattico, Virginia
with an 80mm (3-inch) f/6 Antares Sentinel refractor and a Canon EOS Rebel T2i DSLR.

The Moon wanes in the morning sky this week, her thinning crescent dipping southward along the ecliptic as she enters the rising constellations of the summer sky.  New Moon occurs on February 4th at 4:04 pm Eastern Standard Time.  The last mornings of January find Luna in the company of the bright planets Venus and Jupiter.  You’ll find the Moon nestled between the two planets before dawn on the 31st. 

This week you have another opportunity to do some “citizen science” if you’re not bothered by the chill of the winter air.  We’re in the middle of the first monthly observing campaign for the “Globe at Night” project, which aims to document the visibility of the night sky around the world.  The program was established in 2009, the International Year of Astronomy, and has been going strong ever since.  The process is simple: identify a prominent constellation in your local sky and report the number of stars you see within its bounds.  This month the featured constellation is Orion, which, if you’re reading this, you can probably find with little or no effort.  Orion is probably the most recognized constellation in the sky and crosses the meridian at around 9:00 pm local time.  Once you’ve found him, compare your view to the star charts plotted on the Globe at Night website and create a report.  Since the program began more than 100,000 observations have been recorded, and their target for 2019 is 20,000 reports.  Now is a good time to start submitting yours.

This week is a great time to explore some of the lesser-known parts of the winter sky that lie just to the east of Orion.  From a dark site you’ll notice a faint band of the Milky Way which runs from the center of the constellation of Auriga down to the southeast horizon.  Auriga is directly overhead at 9:00 pm, and it’s a great place to start looking for gems in the galactic stream.  Three prominent star clusters, Messier 36, 37, and 38, reside within the pentagonal outline of Auriga and may be easily spotted in binoculars.  Sweeping southward along the Milky Way brings you to the very obscure constellation of Monoceros, the Unicorn.  Here again you will find the telltale knots of embedded star clusters.  This is one of my favorite parts of the sky to explore with my 4-inch low-power telescope, which resolves many of these clusters into individual stars.  Look about halfway between the bright star Betelgeuse in Orion and Procyon in Canis Minor and you’ll find a truly remarkable object embedded in the star-clouds of the Milky Way.  Here you’ll find a bright star cluster, NGC2244, first observed by British astronomer John Flamsteed in 1690.  Surrounding it is a faint glowing cloud of tenuous gas that covers an area of the sky equivalent to the apparent diameter of the Moon.  Known as the Rosette Nebula, it marks an area of intense star formation located about 5500 light-years from us.  If you continue your sweep down past the bright blaze of Sirius, you’ll land on another bright star cluster, Messier 41, another wonderful sight for the small telescope.  Here again it’s worth scanning the star clouds of the Milky Way that lie east and south of Sirius.  I am constantly amazed at the sheer number of stars you can see with modest optical aid.

Mars remains the sole bright planet in the evening sky, although “bright” is now a relative term.  The red planet is traversing the dim constellation of Pisces, the Fish, which has no star brighter than third-magnitude, against which Mars is a veritable beacon.  He will continue to drift eastward against the stars toward the brighter stars of the Great Winter Circle.

Venus and Jupiter are drifting apart in the pre-dawn sky as Venus trudges eastward through the stars of Sagittarius.  She is still easily spotted in the southeast as morning twilight gathers, but you’ll need a clear horizon to continue following her over the course of the next few weeks.  

Jupiter can be found above the rising stars of Scorpius in morning twilight.  The giant planet rises about three minutes earlier each day.  This will bring him into prominence in the evening sky by late spring.  This week Old Jove and Venus get a visit from the waning crescent Moon.  The trio will form an attractive grouping before sunrise on the 31st.

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