[Music] [Applause] [Music] circumpolar versus seasonal Stars hey there stargazers I'm de RZ astronomer for the Cincinnati Observatory and I'm James alberry director of the Kea Silva plot planetarium in Gainesville Florida far out fellow Stargazer Marlene hadalo will be joining us to help you find your way around the sky tonight we can see some stars and constellations all year round like the Big Dipper in copia While others are only up during certain Seasons like scorpus and the summer triangle why is this let's show you the difference between circumpolar and seasonal Stars okay we have our set up to any night this week facing north at 11:00 p.m. first find the Big Dipper standing on its spoon high in the Northwestern Sky these Seven Stars also Mark the rear end and tail of Ursa Major the Big Bear we can use the two stars on the end of the spoon to point us to Polaris aka the North Star Polaris marks the tip of the tail of the little bear Ursa Miner or the end of the handle of the Little Dipper now if you continue that line from the Big Dipper's handle through Polaris you reach a constellation that looks like the letter W this is the Beautiful copia the queen sitting on her throne these three constellations Ursa Major Ursa Minor and copia are all visible in the sky nearly every night of the year the reason why is that as the night rolls on the Stars will appear to rotate around a pivot point near Polaris this Motion in the heavens is really caused by the rotation of the earth our daily spin causes stars to rise in the east and set in the west but in the north we can watch the Stars spin a full 360 degrees without going below the Horizon that makes them circumpolar Stars when you look at stars farther from Polaris they seem to make a bigger Circle in the sky so the farther south you look the less time each constellation is above the Horizon as the Earth orbits the sun our perspective on the distance Stars changes when we're on one side of the sun like in Winter we can more easily see constellations like Orion and Gemini at night but when we're on the other side of the sun like in summer we can't see Orion and Gemini as well because the glare of the sun is in the way those constellations are only above the Horizon during the day in summer when the nighttime part of the earth is pointed that way then we can see better the constellations like Scorpius and the summer triangle so these are seasonal constellations but no matter what season it is we always have a good view to the northern sky so we in the northern hemisphere can view Ursa Major Ursa Minor and copia all year long that makes them circumpolar constellations so now that we're in summer let's check out the summer triangle look high in the East for the three brightest stars at night zooming in we can see the brightest star Vega is at the top bright white alter is to the right and dimmer denb is to the left Vega is the brightest star in the constellation Lyra the harp alter is the Eagle Eye of Aquilla the eagle and denb is the tale of signis the swan three great summer constellations in one big triangle another easy to find Summer constellation is low in the southern Sky there's Scorpius the Scorpion you won't need to strain your imagination to see a scorpion in the long fish hook of stars that makes his tail and Stinger the brightest star in Scorpius is a beautiful red star named anares anares means rival of Mars because of its similar Hue to the red planet but it's nothing like Mars and teres is one of the largest known stars in the galaxy but at around 600 light years away it's about the same brightness as the closer yet miniature planet Mars with its flickering red flame anares looks like it's the Beating Heart of the sinuous scorpion so get outside tonight and see how the stars move over the night it might take a few hours or days but you'll notice the difference between the circumpolar and seasonal constellations say hi to our old friends Ursa Major Ursa Minor and copia and ring in the Summer with the summer triangle and the Scorpion keep looking [Music] [Applause] [Music] up [Music]