Wednesday, January 2, 2019

The Ellensburg WA sky for the week of 1/5/19

Saturday:  The CWU Physics Department and the College of the Sciences is hosting its monthly First Saturday planetarium show today from noon to 1 p.m. CWU professor Bruce Palmquist will give a presentation called “The sky in different wavelengths”. If you want the chance to say, “look at the pretty colors”, come to this show. The show is free and open to all ages. There will be a show at noon on the first Saturday of every month of the school year hosted by different CWU astronomers and astronomy educators. The CWU Lydig Planetarium is room 101 in Science Phase II, just off the corner of 11th and Wildcat Way, H-11 on the campus map found at 
If you are going to be in northeast Russia this afternoon, there will be a partial solar eclipse to view. For more information about this, go to the NASA solar eclipse website at 

Sunday: This morning is  Venus’ greatest western elongation. So what, you say? Not so what. This means Venus is far from the Sun in the sky. So what, you say? Not so what. This means that Venus is easy to observe. It is two and a half fists held upright and at arm’s length above the south-southeast horizon at 7:15 am. It is the brightest point of light in that part of the sky. Jupiter, the second brightest point of light, is a fist and a half to the lower left of Venus and a fist and a half above the horizon. If you look carefully, you may be able to see Mercury a little bit above the southeast horizon. 

Monday: How do you study the life cycle of a dog? Easy. Get a dog from the animal shelter, care for it for 15 years and study it. How do you study the life cycle of a star? Easy. Pick a star, watch it for a few billion years, and…. Wait a minute. Astronomers can’t observe something for a few billion years. Instead, they study stars that are at different points in their long life cycle and piece together the information from those different stars. What they do is like studying a one-year-old dog for a few minutes, then studying a different two-year-old dog for a few minutes, and so on. The sky in and near the constellation Orion provides an example of four objects at different points of star life. 
First, find Rigel, the bright star in the lower right corner of the constellation Orion. This star, rapidly burning its fuel for a high energy but short-lived existence, is three and a half fists held upright and at arm’s length above due south at 10 p.m. It was not, is not, and never will be like our Sun. However, about one fist up and to the left are the three objects of Orion’s sword holder. The middle “star” is really a star-forming region called the Orion nebula. There you’ll find baby Suns. Now, look about two fists to the right and one fist down from Rigel. You should be looking at a star that is about one tenth as bright as Rigel but still the brightest in its local region. The third star to the right of that star is Epsilon Eridani, the most Sun-like close and bright star. Betelgeuse, in the upper left corner of Orion, is a star at the end of its life that started out life a bit larger than the Sun. 

Tuesday: A week ago today, the NASA probe called New Horizons sent back the first detailed image of Ultima Thule, a Kuiper Belt object (KBO) that formed in its current state about 4.5 billion years ago. Ultima looks like a 30-kilometer long reddish snowman spinning through space. Check out the newest images and the latest information at Astronomers will be downloading and processing the data over the next 20 months. 

Wednesday: Mars, the more well-known red Solar System object, is four and a half fists above due south at 5 p.m. 

Thursday: January 10-13 is the worldwide celebration of 100 hours of astronomy. Of course, the CWU Physics Department started early with the First Saturday planetarium show earlier in the week. The Seattle Astronomical Society will have events in the South King County area Friday and Saturday night. Go to and select “Events” for more information. 

Friday: Have you ever looked down on the ground and spotted a penny? In Yakima? While you were standing in Ellensburg? If you have, then you may be able to see the star Hamal as more than just a point of light. It has an angular diameter that can be directly measured from Earth. Hamal, the brightest star in the constellation Aries the ram, has the same angular diameter as a penny 37 miles away. (For comparison, the moon is about half the diameter of a penny held at arm’s length.) Hamal is three and a half fists above due west at 11 p.m. 
 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

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