Wednesday, November 28, 2018

The Ellensburg WA sky for the week of 12/1/18

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 Bruce Palmquist will give a presentation about the highlights of the winter sky. It’s more than just snow and clouds. 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

Sunday: Venus is two and a half fists held upright and at arm’s length above the southeast horizon at 6:45 a.m. It is at its brightest point this celestial cycle, shining more than twice as bright as when it at its dimmest. The much less bright Mercury is less than a half a fist above the east-southeast horizon at this time.

Monday: The earliest sunset of the year in Ellensburg, Washington occurs throughout the week: 4:13 p.m. This seems odd because the shortest day of the year, the winter solstice, isn’t for about two more weeks. 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 sunrise and sunset times depend on more than the Sun’s apparent southward motion in the sky. 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 leading edge of the analemma, the first section to go below the horizon. For a slightly different explanation about this, go to Or just go watch the sunset. But don’t stare at the Sun.

Tuesday: Comet 46P/Wirtanen is closing in on the Earth and will make its closest approach on December 16. Currently, you need binoculars to see it but some astronomers estimate it could be visible to the naked eye under ideal conditions. It is about three fists above due south at 10 p.m. Don’t look for a sharp point of light, however. Comet 46P will look like a diffuse cloud about the same angular size as the Full Moon, or even larger. For more information and a finder chart, go to

Wednesday: Most constellations don’t look like the object their name refers to. That’s because most constellations don’t have such a simple to object to emulate as Triangulum does. Triangulum is shaped like a… wait for it…. wait for it…. A thin isosceles triangle. Metallah is the only mononymous star in the constellation. In Latin this star is called Caput Trianguli, the head of the triangle. Triangulum is seven fists above due south horizon at 9 p.m. It is pointing down and to the right with Metallah being the southernmost star at this time of night. The Triangulum Galaxy can be seen with binoculars about a half a fist to the right of Metallah.

Thursday: Saturn is a half a fist above the southwest horizon at 5 p.m. Mars is three fists above the south-southeast horizon. Neptune is just to the left of Mars but you’ll need binoculars to see it.

Friday: Earlier this week, we learned that the early December evenings are getting darker earlier than any time of the year. While the sky is getting darker earlier, the nighttime sky is actually getting lighter due to the greater use of low energy LED bulbs. While these bulbs use much less energy that incandescent or compact fluorescent bulbs, researchers think that people and communities are using more of the bulbs and leaving them on longer. This is increasing light pollution near cities. You can get more illumination on the subject at

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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