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and check out our online courses. Welcome, my name is Janine and in this
video we will review the pattern, bright stars, celestial objects, and mythologies
about the constellation known as Boötes. So Boötes is a pretty recognizable
constellation and one that's easy to find. The reason for that is that Ursa
Major, or part of the Big Dipper, points directly to Boötes's brightest star,
which is known as Arcturus, in fact if you can memorize that term 'arc to
Arcturus' you should easily be able to find this constellation in the spring
sky. So let's take a look at what it looks like, so when you're looking at
this picture hopefully you can see the bright, orangish color star towards the
bottom of the picture, and that is known as Arcturus, and in many different
cultures it has different names to represent that star. So once you find
that star what you want to try to do is see if you can find a kite like shape
right above that star. So this is what Boötes looks like. This other bright star
right here is a part of the Big Dipper, so you're looking at the last little
star in the handle of the Big Dipper, so if you can arc down the side of Boötes
you can find Arcturus, and there's another constellation that's easily
recognizable in this picture as well, and that's known as Corona Borealis. Go see
that video if you want to know more about this fascinating constellation, but
Corona Borealis kind of looks like C on its side or I like to think of it
as a smile, as the stars are smiling back at me.
So Boötes and Corona Borealis are seated right next to each other in the
sky. Now let's get some practice being able to find Boötes, so as you look at
this beautiful sunset picture, with the stars that are starting to appear, try to
find the Big Dipper. If you can find the Big Dipper move to the handle and you
arc to Arcturus, from there are you able to point out the kite leg shape
that makes up Boötes? So just to help you find it here's the Big Dipper,
right there, so you arc to Arcturus and then the other part of that is speed to
Spica, so you would speed to Spica which is another bright star in the
constellation Virgo, but moving back to Arcturus here is that
kite like shape, right here, that's attached to Arcturus. So remember you
should arc to Arcturus and speed to Spica. Memorize this little phrase and
you'll always be able to find this constellation. The bright star of
Arcturus is also part of an asterism called the Spring Triangle. Now an
asterism is not a true constellation, it's just another pattern that's within
other patterns that can help you navigate your way across the sky. If you
want to know more about asterisms go watch that video, but here you can see
Arcturus, Spica, which is a part of Virgo, and Regulus, or Regulus
depending on who you talk to is a part of Leo, and if you live in a place that
has a decent amount of light pollution these are the stars that you should look
for in the spring sky, because they stand out, they're really really bright, and if
you can find the spring triangle then you should be able to find the other
constellations as well that surround it. You can also see this red dotted line
right here, this is another version of the spring triangle, and here is another
version, so there's kind of a series of triangles you can make with the bright
stars that are in this arena. Now let's examine
the brighter stars of Boötes in greater detail. So you're aware of Arcturus, it is
the Alpha star of this constellation, and it comes from the Greek name arktoutos,
which means 'guardian of the bear', it is an orangish yellow star and it's the
brightest star that's north of the celestial equator, and it's the fourth
brightest star in the entire night sky. It's only 36 light years away and when
we look at it in closer detail we can learn more about its size. So here is a
size comparison of the Sun Vs Arcturus Vs a red giant star like Antares.
Antares is in the constellation Scorpio, so feel free to visit that video for
more information, but Arcturus is larger than the Sun,
but again not as large as Antares, and it's very bright. Another fascinating
story about the star known as Arcturus is how it was used as a guiding star to
help others navigate across large large spaces. Prehistoric Polynesian navigators
knew Arcturus as Hokulea, which is stands for 'the star of joy' and Arcturus was the
zenith star of the Hawaiian Islands, so they were able to use Hokulea and other
stars to launch their double-hulled canoes from Tahit,i to the Marquesas
Island, and then traveling all across the Pacific Ocean and eventually landing at
Hawaii and this was no accident, the Polynesian navigators knew exactly what
they were doing and I find this just such an interesting and fascinating
story, and in fact the Hokulea double hull canoe that just made the worldwide
voyage around the world from 2014 to 2017 is named after this star because it
has such a significance in the Polynesians navigating across the ocean.
So another one is Epsilon Boötis, and this is a binary star system that's really
interesting, it's 203 light-years away, that's its
approximate distance, and it has two stars. It has this primary star, which is
kind of a misconception in this photo, because this really is the main primary
star, it's an orange K class star. It's four times the mass of the Sun,
thirty-three times the radius, and 500 times more luminous than the Sun, but it
has this secondary star, and this is a whitish blue main sequence star and it's
burning through as hydrogen really quickly, so that tells us it's a young
star, and by the time that primary star runs out of its fuel then the secondary
star is going to turn into a planetary nebula and they'll kind of switch phases.
So right now this is the the larger one, well while this is the smaller one, but
eventually that will reverse. So definitely an interesting star system
for sure. Now that we know the pattern and bright stars of Boötes let's look at
the celestial objects that can be seen within its boundaries. When we look at
the constellation map of Boötes you can see that there's not really a lot of
celestial objects that are there, but let's look at the ones that are there. So
first we have NGC 5466, and this is a globular cluster, it's
estimated to be 47,000 light-years away,
so remember globular clusters are clusters that hover around the halo of
the galaxy, they're not in the disk whatsoever, they're only above and below
the core of the galaxy. So this just gives you an idea of the area of the
galaxy that you're looking at, and if we were to zoom in closer this is what it
would look like, now this this image is taken with a high-power telescope, but I
never really get tired of these beautiful globular star clusters, they're
they're quite amazing. Next we have something called the Boötes void, and
this is a huge space that seems to be almost empty of
galaxies, and if we look a little closer right here without the label you can see
that there's different voids within the areas that we've used. So the Boötes void
is here, and you can see that these different voids are just areas that are
lacking galaxies. Now why is this? We're not really sure but as technology has
become a bit more sophisticated astronomers have been able to detect
some galaxies within this void, so far, with the Boötes void
60 galaxies have been discovered. This whole area is estimated to be 33 hundred
million light-years in diameter. So that is pretty amazing when we think about
all that we're looking at. Finally we'll examine a few of the mythologies of
Boötes, it is often the stories of the stars that we can connect to in some way,
which can help us remember the constellation patterns and remember
there are as many mythologies about constellations as there are stars, so
there really is no one correct mythology. So let's take a look at a Greek legend,
according to this legend Boötes is represented by Arcas, which is a demigod
and the son of Zeus. In this story Zeus had a lady on the side known as Callisto,
and she was the daughter to the king of Arcadia, and one day Zeus came down from
Mount Olympus to dine with them and this was pretty unusual for a god so in order
to see if it was truly Zeus the King of Arcadia caught up Arcas and served him
as a mixed grill. Zeus easily recognized that the dinner served to him was his
son. In his rage he killed the sons of the king with a thunderbolt, and turned
the king into a wolf. Zeus then collected these parts and put him whole, brought it
back to life, and then he returned him to the stars. So that's one that's one
legend, another one is that Zeus's wife Hera
heard of her husband's infidelity and transform Callisto into a bear.
Callisto then roamed the woods and years later she met her son, who was now grown
up, and Arcas didn't recognized his mother and began to chase her down, so Callisto
was within this temple that was a sacred place, so therefore Arcas couldn't hurt
her without being sentenced to death. So in order to avoid a tragedy all together,
and the son unknowingly killing his mother,
Zeus placed them both in the sky where Arcas became the constellation Boötes.
Let's review everything we learned about Boötes the herdsman constellation. It is
best seen in the spring months in the northern hemisphere, particularly during
the month of May, and it's classified as a seasonal constellation. The best way to
find it is to arc to Arcturus, using the handle of the Big Dipper.
The celestial objects include a few globular clusters, some galaxies that you
would need magnification to see, and the Boötes void. So good luck at finding this
constellation, if you arc to Arcturus, find the kite-like shape, and look for
the smile right next to Boötes you should be able to find this constellation. Good
luck and keep looking up.