The Ellensburg, WA sky for the week of October 22, 2022

Saturday: Halloween is early next week so make sure you load up on peanut clusters, almond clusters, and open star clusters this week. That last one will be easy (and cheap… actually free) because two of the most prominent open star clusters in the sky are easily visible in the autumn sky. The sideways V-shaped Hyades Cluster is two fists held upright and at arm’s length above due east at 10:00 p.m. Containing over 300 stars; the Hyades cluster is about 150 light years away and 625 million years old. The Pleiades Cluster, a little more than three fists above due east, is larger at over 1000 stars and younger. Compared to our 5-billion-year-old Sun, the 100-million-year age of the Pleiades is infant-like.

Sunday: Three years ago, the Hubble Space Telescope got the first close-up view of a comet from another star system. Comet 2I/Borisov was discovered by amateur astronomer Gennady on August 30, 2019 as the second interstellar object ever confirmed. 2I is the new official designator for the second interstellar object. Astronomers know it is from another star system because it is going way too fast, 110,000 miles per hour, to be gravitationally bound to the Sun. Read and watch more about the discovery at http://tiny.cc/mhh0tz.

Monday: At 10:00 p.m., Saturn is about two fists above the south-southwestern horizon, Jupiter is exactly four fists above the south-southeastern horizon, and Mars is about one fist above the east-northeastern horizon.

Tuesday: At about 4:00 am Pacific Daylight Time, the moon will pass between the Earth and the Sun. But because they are not perfectly lined up, the moon will only partially block the Sun, resulting in a partial solar eclipse. Read more about the eclipse at https://www.timeanddate.com/eclipse/solar/2022-october-25, including information on watching a livestream. If you’d like to see the eclipse live, you’ll have to travel to Europe, northeast Africa, the Middle East, or western Asia.

Wednesday: What time is teatime? Certainly not during an autumn evening. The constellation Sagittarius the archer, with its signature teapot shape, is sinking into the south-southwestern horizon by 7:00 p.m. The handle is on top and the spout is touching the horizon ready to pour that last cup of tea. 

Thursday: At 6:30 p.m., the bright star Antares is about two finger-widths to the left of the young crescent moon. They are just above due southwest.

Friday: Halloween weekend is a great time to celebrate the dead. Dead stars, that is. Black holes are and neutron stars are the end result of super massive stars. But intermediate mass stars such as our Sun end up as white dwarfs. After fusing hydrogen into helium for most of its life and fusing helium into heavier elements for a relatively brief period at the end of its life, the Sun will end up with a core of carbon and oxygen that no longer produces energy through nuclear fusion. Without the outward radiation pressure from fusion resisting the inward pull of gravity, the Sun will end up as a super-dense sphere of atoms in which the electrons are squished onto the nuclei. It will be an object with nearly all its mid-life mass but in a volume about the size of the Earth. The easiest white dwarf to see is in the triple star system called Keid, from the Arabic word “qayd” meaning eggshells. Learn more about Keid, also called 40 Eridani, including map of how to find it at https://www.skyandtelescope.com/observing/trick-or-treat-with-white-dwarfs/. At midnight (scary), Keid is a little more than two fists above due southeast. You’ll need a small telescope to see it. First find Rigel, the brightest star in the constellation Orion. It is one and a half fists above the east-southeastern horizon. Then use binoculars to find the right area. With Rigel at the bottom of your field of view. There should be a star near the top of your girls of view that is about one sixth as bright. This star is called Cursa. Next, move your binoculars up and to the right about one and a half field of view diameters. Look for two stars close together, each about one third as bright as Cursa. Finally, move your binoculars straight over to the right about one and a half field of view diameters. The lower of these two stars is Keid or 40 Eridani A. You’ll need a telescope to see the white dwarf, called 40 Eridani B.

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.