The Ellensburg, WA sky for the week of December 21, 2019

Today: At 9:20 p.m., Pacific Standard Time, the Sun reaches its lowest point in the sky with respect to the background stars. This point is called the Winter Solstice. During the day that the Sun reaches this point, your noontime shadow is longer than any other day of the year. Also, the Sun spends less time in the sky on the day of the Winter Solstice than any other day making this the shortest day of the year. Even though it is the shortest day of the year, it is not the day with the latest sunrise or the earliest sunset. The latest sunrise is during the first week in January and the earliest sunset is during the second week in December. The Sun is at its southernmost point with respect to the background stars on the day of the winter solstice. This means the Sun spends the least amount of time above the horizon on that day. But, the Sun rise and set time depends on more than its apparent vertical motion. It also depends on where the Sun is on the analemma, that skinny figure-8 you see on globes and world maps. During the second week in December, the Sun is not quite to the bottom of the analemma.  But, it is on the first part of the analemma to go below the horizon. During the first week in January, it is on the last part of the analemma to rise above the horizon.

Sunday: I know you’re staying up late to train yourself to wait up for Santa. So look out a south-facing window tonight at 12:41 a.m. and see Sirius, the brightest star in the nighttime sky, as high as it ever gets in the sky. It is two and a half fists held upright and at arm’s length above due south.

Monday: Are you disappointed because you are not going anywhere for Christmas? Why not take a (virtual) trip to outer space using Google’s new visualization tool called 100,000 Stars. It shows the stars in our neighborhood in a very good 3-D simulation. The Sun is initially at the center. If you zoom in, you can click on neighboring stars and learn more about them. Go to http://stars.chromeexperiments.com/ for the simulation. It works best on a Chrome browser.

Tuesday: At 5:00 p.m., Saturn is a half a fist above the southwestern horizon and the much brighter Venus is nearly one and a half fists above the southwestern horizon. If you are getting up early tomorrow to open presents, look outside and find Mars nearly two fists above the southeastern horizon at 7:00 a.m.

Wednesday: Where is the one who has been born King of the Jews? We saw Jupiter being eclipsed by the Moon in the east and have come to worship him” (Matthew 2:2, Bruce Palmquist version, informed by Michael Molnar). There are many theories as to the physical explanation of the Star of Bethlehem, the celestial object that guided the wise men to the location of Jesus. Some people think it was a recurring nova, a star that explodes. Some think it was a close alignment of bright planets. Some think it was a miracle that requires no physical explanation. In 1991, astronomer Michael Molnar bought an ancient Roman Empire coin that depicted a ram looking back at a star. Aries the ram was a symbol for Judea, the birthplace of Jesus. The Magi, or “wise men”, who visited the baby Jesus practiced astrology and would have been looking in that region of the sky for the king prophesied in the Old Testament. Molnar, a modern day wise person, used sky simulation software to model the positions of planets and the Moon in the region of Aries. According to his model, Jupiter was eclipsed, or blocked, by the Moon on the morning of April 17, 6 BC. A book written by the astrologer of Constantine the Great in 334 AD supports Molnar’s theory. The book describes an eclipse of Jupiter in Aries and notes a man of divine nature born during this time. See https://goo.gl/o89A4o for more information.

Only Aries make an appearance in the Christmas sky this year. At 8 p.m., the dim constellation Aries is six and a half fists above due south. Jupiter is lost in the glare of the Sun. The Moon is in the New phase so the illuminated side is facing away from Earth.

Thursday: Did you get a new telescope for Christmas? The next item on your list should be a sky watching app for your phone. These apps will help you to get familiar with the constellations and bright stars. Then you can zoom in to an area of interest and learn about objects that are visible through your telescope. I like SkySafari, a free app for iPhones. But there are many other good ones to choose from for little or no money. Go to https://goo.gl/t1DX7R for fifteen short reviews. The first object you should look at is Mars. It is bright, easy to find and out in the early evening sky so you can share the experience with children. Mars is four fists above the south horizon at 6 p.m.

Friday: So, you are not into virtual vacations like the Google Simulation, hmmm? How about a vacation to the recently discovered Super Earth sized planet orbiting the closest single star to our Sun? Astronomers working with the European Southern Observatory discovered that Barnard’s Star, a red dwarf star only 6 light-years away, has a planet about three times the mass of the Earth. Even though Barnard’s Star is very dim, it is heavily studied because it is the star with the largest proper motion. It moves through the night sky more than any other star.  Don’t expect a warm vacation. This planet receives only 2% of the energy from its star as we receive from the Sun. For more information about the discovery, and to possibly book a trip, go to http://www.portaltotheuniverse.org/news/view/658855/.  Barnard’s Star is about one fist above due east at 7:00 a.m., to the lower left of the fairly bright star Cebalrai.

The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to https://nightsky.jpl.nasa.gov/planner.cfm.