Saturday: This
evening, Venus is as far away from the Sun in the sky as it will get this
orbital cycle. What is this "farthest away" point known as? It is
known as the planet’s greatest eastern elongation. Tonight is one of the best
nights of the year to observe Venus because it is high in the sky at sunset and
will be in the sky until nearly midnight. Venus is two fists held upright and
at arm’s length above the west-northwest horizon at 10 p.m. Over the next two
months, Venus will move toward the Sun in the sky. By the end of July, it will
be lost in the glare of evening twilight.
Sunday: Jupiter
is two and a half fists above the west horizon and a fist and a half to the
upper left of Venus at 10 p.m.
Monday: Nearly
400 years ago, Galileo viewed the Pleiades star cluster through his telescope
and saw that the seven or so stars in the region visible to the naked eye
became many more. There are two main types of star clusters. Open star clusters
are groups of a few dozen to a few thousand stars that formed from the same
cloud of gas and dust within our galaxy. Stars in open star clusters are young
as far as stars go. Globular clusters are groups of up to a few million stars
that orbit the core of spiral galaxies such as our own Milky Way. One of the
most well known star clusters is the globular cluster in Hercules, an object
that is fairly easy to find with binoculars. First find Vega, the bright bluish
star five fists above the east horizon at 11 p.m. Two fists above Vega is a
keystone shape. Aim your binoculars at the upper left hand star of the
keystone. The globular cluster is one third of the way to the rightmost star of
the keystone. It looks like a fuzzy patch on the obtuse angle of a small obtuse
triangle. If you don’t know what an obtuse angle is, you should not have told
your teacher, “I’ll never need to know this stuff”.
Tuesday: Saturn
is about two fists above the south-southeast horizon at 10 p.m.
Wednesday:
When it is sitting low in the western sky, many people mistake the star Capella
for a planet. It is bright. It has a slight yellow color. But, Capella is
compelling on its own. It is the fourth brightest star we can see in
Ellensburg. It is the most northerly bright star. It is a binary star
consisting of two yellow giant stars that orbit each other every 100 days. At
10 p.m., Capella is two fists above the north-northwest horizon. If you miss it
tonight, don’t worry. Capella is the brightest circumpolar star meaning it is
the brightest star that never goes below the horizon from our point of view in
Ellensburg.
Thursday: What
you see with the naked eye isn’t all that can be seen. While astronomers can
learn a lot from observing the sky in the visible wavelengths, many celestial
objects radiate more light, and more information, in wavelengths such as radio,
microwave, infrared, ultraviolet, x-ray, and gamma ray. In 2009, NASA launched
the Wide-field Infrared Survey Explorer (WISE) to study objects that radiate in
the infrared range such as asteroids, cool dim stars, and luminous galaxies.
For an interesting comparison of how different wavelengths show different
aspects of a galaxy, go to http://goo.gl/nvuax. If it weren’t for infrared
telescopes such as WISE, astronomers would not know about the significant
amount of dust in galaxies.
Friday:
Summer is nearly here. How do I know? Because kids are getting out of school.
Because I read the fine astronomy column in the Daily Record. (How’s that for
an odd self reference.) Also, because the Summer Triangle is fairly high in the
eastern sky at 10:30 p.m. Vega, the third brightest star visible from
Ellensburg, is about five fists above the east horizon. Deneb, at the tail of
Cygnus the swan is about three and a half fists above the northeast horizon.
The third star in the triangle, Altair, in Aquila the eagle is two fists above
the east horizon.
If you
want to put somebody off, tell her or him to wait until Deneb sets. At
Ellensburg’s latitude of 47 degrees, Deneb is a circumpolar star meaning it
never goes below the horizon.
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 http://nightsky.jpl.nasa.gov/planner.cfm.
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