Wednesday, January 6, 2016
The Ellensburg WA sky for the week of 1/9/16
Saturday: 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.
Sunday: Do you see a hunter when you look at Orion? Betelgeuse and the bright star one fist to the right of it are the broad shoulders of the hunter. Rigel and Saiph, the bright star to the left of Rigel, represent the knees. The Maya saw the equilateral triangle formed by Rigel, Saiph, and the left-most belt star as the “Three Stones of the Hearth”. The Orion Nebula is in the center of the hearth and it represents the flame, called K’ak.
Monday: Star Wars: The Force Awakens with its strangely shaped light saber is showing in theaters. The awakened force of a star is showing in the Orion B molecular cloud complex. When stars form, gas and dust is gravitationally pulled in and jets of energized gas shoot out its poles. The Hubble Space Telescope has taken images of twin jets that resemble Darth Maul’s double bladed light saber in Star Wars Episode 1. For more information about this star, along with more marginally accurate references to Star Wars, go to http://goo.gl/zOyZYb.
Tuesday: Jupiter is one fist above the east horizon
Wednesday: January is the coldest month of the year so it is time to turn up the furnace. Fornax the furnace is one fist above due south at 7 p.m.
Thursday: Are you a morning person? Good, because you’ll see quite a show in the morning sky from January 20 to February 20. All five naked eye planes will be visible before sunrise. Even now, you can see four of the five naked eye planets. Jupiter is three fists above the southwest horizon. Mars is three fists above the south horizon. Venus, the brightest planet, is more than one fist above the southeast horizon. Saturn is a half a fist to the upper right of Venus. In about a week, Mercury will move out of the glare of the Sun and join it’s fellow planets in the morning sky.
Friday: Sirius, the brightest star in the nighttime sky, is two and a half fists above due south at 11:15 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 http://nightsky.jpl.nasa.gov/planner.cfm.