Saturday: Today: 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 10:00 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 larger than the
Sun.
Sunday: At 7:00 p.m., Saturn is two fists above the
southwestern horizon and Jupiter is more than five fists above the
south-southeastern horizon.
Monday: Viewers in the Western United States may be able to
see the waning crescent moon occult the bright star Antares. This doesn’t mean
the moon and Antares will be joining a non-mainstream religion with an overly
charismatic leader. It means the moon will block, or occult, Antares for about
an hour. From Ellensburg, Washington, find the moon near the southeastern
horizon at 5:30 a.m. Antares will be to the lower left of the moon. By about
5:36 a.m., the moon will have moved between the Earth and Antares. By about
6:40 a.m., Antares will reappear from behind the upper right portion of the
moon. It will look as if the star just popped into existence because it will be
coming from behind the unlit portion of the moon.
Tuesday: 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 two and a half fists above
the east-southeastern horizon at 10:00 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.
Wednesday: In 1984, American singer Rockwell released the
song “Somebody’s Watching Me”, backed up by Michael Jackson. In 2020, NASA’s
Spitzer Space Telescope released a picture of two bubbles of gas and dust that
look like eyes watching you. Stare back at them by going to http://tiny.cc/w99nuz.
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: Mercury will be as far away from the Sun in the sky
as it will get this orbital cycle. This "farthest away" point is
known as the planet's greatest elongation. Since Mercury is in the morning sky,
it is west of the Sun and this occurrence is called the greatest western
elongation. This morning, Mercury is a half a fist above the southeastern
horizon at 6:45 a.m. Over the next few weeks, Mercury will move toward the Sun
in the sky. By mid-March, it will be visible in the evening sky.
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.
No comments:
Post a Comment