Thursday, January 16, 2020

The Ellensburg, WA sky for the week of January 18, 2020


Saturday:  Winter is the best season for finding bright stars. And if you only want to set aside a few minutes, 10 p.m. tonight just might be the best time because the winter hexagon is due south. Starting at the bottom, find Sirius, the brightest star in the night sky, two and a half fists held upright and at arm’s length above the southern horizon. Going clockwise, Procyon (6th brightest star visible from Washington state) is about two and a half fists to the upper left of Sirius. Pollux (12th brightest) is about two and a half fists above Procyon. Capella (4th brightest) is about two and a half fists to the upper right of Procyon and close to straight overhead. Going back to Sirius at the bottom, Rigel (5th brightest) is about two and a half fists to the upper right of Sirius. Aldebaran (9th brightest) is about three fists above Rigel. Adhara (16th brightest) is a little more than a fist below Sirius and Castor (17th brightest) is right above Pollux. Betelgeuse (21st brightest) is in the center of the hexagon. That’s nine of the 21 brightest stars visible in the northern United States in one part of the sky. This list used to be nine of the 17 brightest. But Betelgeuse has dimmed from the 7th to the 21st brightest star in the sky. For more information about this dimming, go to https://youtu.be/FosDJOVaKFc

Sunday: Mars is on the south-southeastern sky, less than a half a fist to the lower left of the waning crescent Moon at 7:00 a.m. Jupiter is just above the southeastern horizon.

Monday: Let’s review three important sets of three cats. There’s Josie, Valerie, and Melody of Josie and the Pussycats. Felix, Tom, and Sylvester from old time cartoons. And, if you want to get away from the mind-numbing effects of television, there’s Leo the lion, Leo Minor, and Lynx in the night sky. Leo is by far the most prominent of these three constellations. Its brightest star called Regulus is three and a half fists above the east-southeastern horizon at 11 p.m. The backwards question mark-shaped head of Leo is above Regulus and the trapezoid-shaped body is to the left of it. Leo Minor consists of a few dim stars right above Leo. Pretty wimpy. The long dim constellation called Lynx spans from just above Leo Minor to nearly straight overhead. You and fellow stargazers won’t need to wear a long tail or ears for hats to enjoy these stellar cats.

Tuesday: Venus is two fists above the southwestern horizon at 6:00 p.m.

Wednesday: You never see a giraffe on the ground in Ellensburg. But you can look for one every night in the sky. The constellation Camelopardalis the giraffe is circumpolar from Ellensburg’s latitude of 47 degrees north meaning it is always above the horizon. Don’t expect to be overwhelmed by the appearance of the stars in Camelopardalis. The brightest star in the constellation appears only about half as bright as the dimmest star in the Big Dipper. However, the actual luminosities of the three brightest stars in Camelopardalis are very high, each at least 3,000 times more luminous than the Sun. Alpha Camelopardalis, a mind boggling 600,000 times more luminous than the Sun, is seven fists above the northern horizon at 9:00 p.m.

Thursday: Draco Malfoy makes an appearance in all seven books of the Harry Potter series. Perhaps you’ve heard of these. But, the constellation Draco the dragon makes an appearance in the sky every night. It is a circumpolar constellation as viewed from Ellensburg meaning it never goes below the horizon. The head of the dragon is one fist above due north at 9:30 p.m. Eltanin, the brightest star in the constellation, is at the lower left-hand corner of the trapezoid-shaped head of Draco.

Friday: The moon is almost directly between the Earth and the Sun today. That means you won’t be able to see it. But that does not mean it doesn’t exist. Contrary to the belief of toddlers and immature politicians, just because you can’t see something doesn’t mean it doesn’t exist. (Note a double negative statement followed by a triple negative statement. I’m not unsorry about that.) Now, back to the science. What would happen to the earth if the moon really didn’t exist? In that 2013 blockbuster Oblivion, aliens destroy the moon and Tom Cruise survives. But the long-term effects on the earth would be devastating to life as we know it. The moon stabilizes the spin axis of the earth keeping the seasons fairly uniform over time. For more information on what would happen to the earth if the moon were destroyed, goto https://www.popsci.com/what-would-happen-if-moon-suddenly-disappeared/. For more information on Thomas Cruise Mapother IV, go to http://en.wikipedia.org/wiki/Tom_Cruise.

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.

Thursday, January 9, 2020

The Ellensburg, WA sky for the week of January 11, 2020

Saturday:   Last Saturday's planetarium show had some technical difficulties. So, we will be redoing the show today from noon to 1 p.m. CWU physics graduate and future science teacher Jessica Kisner will give a show about the winter sky. The nights are long and the sky is (sometimes) crisp and clear. So you ought to know what you are looking at. 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 https://www.cwu.edu/facility/campus-map.

Sunday: 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. Betelgeuse has been in the astronomy news lately because it has fallen from the 10th brightest star to the 21st brightest star in the night sky. Supergiant stars such as Betelgeuse are unstable and vary in size and shape over their years as a supergiant. These variations lead to variations in brightness. Astronomers think that a few different variation patterns that lead to slight changes in brightness individually are all happening at the same time, leading to a larger drop in brightness. For more information, go to https://www.skyandtelescope.com/observing/fainting-betelgeuse

Monday: When someone is angry, they may say “I’m seeing red.” For the next few days, people who  observe the morning sky will also see red. Mars and its rival Antares are neighbors in the sky for the next few days. Lest you think I am drumming up a fake rivalry, the prefix “ant” means “against”, “opposite”, or “rival”.  Ares is the Greek counterpart to the Roman god of war, Mars. So Antares literally means “rival to Mars”. At 7:00 a.m., Antares is one fist above the south-southeastern horizon and Mars is half a fist above it.

Tuesday: Venus is one and a half fists above the southwestern horizon at 6:00 p.m.

Wednesday: These next two weeks are the coldest 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: 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 fists above due west at 11:00 p.m.

Friday: Jupiter is finally starting to come out of the glare of the Sun in the morning sky. It is just above the southeastern horizon at 7:00 a.m. You’ll need a flat and clear horizon to see it.

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.

Thursday, January 2, 2020

The Ellensburg, WA sky for the week of January 4, 2020


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 physics graduate and future science teacher Jessica Kisner will give a show about the winter sky. The nights are long and the sky is (sometimes) crisp and clear. So you ought to know what you are looking at. 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 https://www.cwu.edu/facility/campus-map.

Sunday: If the Sun looks big today, your eyes are not playing tricks on you. The Earth was at perihelion a little before midnight last night, Pacific Standard Time. If you dig out your Greek language textbook, you’ll see that peri- means “in close proximity” and helios means “Sun”. So, perihelion is when an object is closest to the Sun in its orbit, about 1.5 million miles closer than its average distance of 93 million miles. Since it is winter in the Northern Hemisphere now, the seasonal temperature changes must not be caused by the Earth getting farther from and closer to the Sun. Otherwise, we’d have summer when the Earth is closest to the Sun. The seasons are caused by the angle of the sunlight hitting the Earth. In the winter, sunlight hits the Earth at a very low angle, an angle far from perpendicular or straight up and down. This means that a given “bundle” of sunlight is spread out over a large area and does not warm the surface as much as the same bundle in the summer. For the Northern Hemisphere, that very low angle occurs in December, January and February.

Monday: The Moon makes a triangle with the open star clusters called the Pleiades and the Hyades throughout the night. At 6:00 p.m., the Moon is above the east-southeastern horizon. The Hyades cluster is about a fist to the lower left of the Moon and the Pleiades is about a fist to the upper left of the Moon. By 4:00 a.m., they are nearly in line with each other just above the west-northwestern horizon.

Tuesday: Do you look into a nursery and say, “it’s a boy” or “it’s a girl”? Not me. I say, “It’s a star”. Of course, I like looking into a stellar nursery – a star-forming region such as the Orion Nebula in the middle of Orion’s sword holder. The Orion Nebula looks like a fuzzy patch to the naked eye. Binoculars reveal a nebula, or region of gas and dust, that is 30 light years across. The center of the nebula contains four hot “baby” stars called the Trapezium. These hot stars emit the ultraviolet radiation that causes the Nebula’s gas to glow. The Orion Nebula is nearly four fists above due south at 10:30 p.m.

Wednesday: Venus is one and a half fists above due southwest at 5:30 p.m.

Thursday: Just over a year ago, the NASA probe called New Horizons sent back the first detailed images of Arrokoth, also called 2014 MU69, a Kuiper Belt object that formed in its current state about 4.5 billion years ago. Arrokoth looks like a 30-kilometer long reddish snowman spinning through space. Check out the newest images and the latest information at http://pluto.jhuapl.edu/. Arokoth means “sky” in the Powhatan/Algonquian language. Astronomers first nicknamed the object “Ultima Thule”, meaning a place beyond the known world. But Nazis and Neo-Nazis had co-opted that term long ago, leading to the official, much more meaningful name. Arrokoth is red, just like Mars. You can’t see Arrokoth in the sky. But you can see Mars at 6:30 a.m., one and a half fists above the southeastern horizon.

Friday: Tonight’s Full Moon is called the Full Wolf Moon since wolves tend to howl more often in the cold winter nights.

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.