Wednesday, April 19, 2017
The Ellensburg WA sky for the week of 4/22/17
Saturday: If you don’t want to stay up late looking at the stars, do something during the day that will help you and other night sky enthusiasts: make sure your outdoor light fixtures are shielded or at least facing down. This will cut down on light pollution, stray light that obscures the stars, and give you a head start in celebrating International Dark Sky week, which starts today. Go to http://goo.gl/w6Hi7 for more information on how to do an outdoor lighting audit and get more information about International Dark Sky week. You won’t need to have dark skies to see Mars about one fist held upright and at arm’s length above the west-northwest horizon at 9 p.m.
Sunday: The bright planet Venus is less than a fist to the upper left of the waning crescent Moon, low in the eastern sky at 5:30 a.m. And I do mean bright. Venus is at the brightest part of its orbit this week.
Monday: The nighttime stars take little more than an instant to rise. The Moon takers about two minutes to rise. That’s absolutely speedy compared to the constellation Virgo, which takes four hours to rise. The first star in Virgo rises at 4:30 in the afternoon. Spica, the brightest star in the constellation, rises at 7:30. By 9 p.m., Spica is one and a half fists above the southeast horizon. The much brighter planet Jupiter is one fist above Spica.
Tuesday: Ah, the signs of spring. Trees budding. Flowers blooming. Young lovers frolicking. The Spring Triangle rising. In order of brightness, Arcturus, Spica, and Regulus form a triangle that rises as the Sun is setting. By 9 a.m., Regulus is five fists held upright and at arm’s length above due south, Spica is one and a half fists above the southeast horizon, and Arcturus is three fists above the east horizon. For the next few months, Jupiter joins the triangle, five fists above the south-southeast sky.
Wednesday: Do people think you have a magnetic personality? The star Cor Caroli understands how you feel. Cor Caroli has one of the strongest magnetic fields among main sequence stars similar to our Sun. This strong magnetic field is thought to produce large sunspots that cause the brightness of Cor Caroli to vary. Cor Caroli is nearly straight overhead at midnight.
Thursday: Winter must be over because the winter constellations are becoming less visible. Orion is setting in the west starting at about 9 p.m. At this time, Orion’s belt is one fist above the west-southwest horizon and Betelgeuse is nearly two fists above the west horizon. By mid-May, Orion will be lost in the glare of the Sun.
Friday: Global Astronomy Month concludes at noon Pacific Daylight Time with the Cosmic Concert performed by Italian pianist and composer Giovanni Renzo. For more information, including information on audience participation, go to https://goo.gl/rC0qbz.
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.