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fandomhigh2006-06-28 09:14 am
stargazer-ellie.livejournal.com) wrote in fandomhigh2006-06-28 09:14 am
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Observational Astronomy -- June 28
Week 6 - June 28 - The Summer Triangle: Lyra, Cygnus, Aqulia
[Class Roster ]
Star maps: East | West | North | South | Overhead
There were some extra students for tonight's class, and when everyone gathered, Ellie reminded them. "We're being joined tonight by Veronica Mars and her photography class," she said. "They're going to be learning about night photography." Then she began the night's lecture:
"Three brilliant stars form the Summer Triangle, making it our best heavenly landmark in the summer night sky." She traced out the distinctive triangle with her laser pointed. "Vega, high above and its western point, appears the brightest of the three." Ellie's voice was especially wistful when talking about Vega. "Deneb, also high above and to the east of Vega, appears the dimmest. Altair shines below in the south, forming the most distant point of this great triad.
"These three stunning stars are an unofficial star group, or asterism, that link three constellations: Lyra, Cygnus the Swan, and Aquila the Eagle.
"You can't help but notice a really bright star that's almost straight up. That star is the renowned Vega. Vega is a zero magnitude star, about the same apparent brightness as Arcturus, and is the fifth brightest start in the sky. It is actually 25 light years away, nearly twice as far as Altair, three times the mass of the sun, and about 50 times as bright as the sun. Imagine having 50 suns in our sky. If Vega was our sun we'd be cooked.
"Vega is part of the constellation of Lyra the Lyre. It is easily recognizable as a parallelogram of four stars right next to the very bright Vega. This constellation represents a lyre, or harp, with Vega at the top of the lyre as one of the handles. The other handle must have broken off. The lyre belongs to Orpheus, and was given to him by his father, Apollo.
"M57, also known as the Ring Nebula, is one of the finest planetary nebula in the skies. It's also known as 'The Doughnut Nebula' in Japan. The central star, now a white dwarf, blew off a shell of gas as it died, creating the ring. It is about 2100 light years away, and while the naked eye cannot see the colors of the ring, processed images show the nebula has a bluish interior, yellow to white in the ring itself, and reddish colors in outer edge.
"The next constellation we reach is Cygnus the Swan. This constellation is also known as the Northern Cross and at Christmas time, in the evening, it has rotated across the sky so it is standing on its base on the northwestern horizon, with the bright star Vega next to it. Very Christmas-y.
"Deneb is the star at the tail of the Swan. Notice that it is about as bright as Altair, which is 16 light years away -- so how far would you guess Deneb is? As it happens... Deneb is 2600 light years away - about 150 times farther! Deneb is actually 20,000 times brighter than Altair and 200,000 times brighter than our sun. If Deneb were as close as Altair, it would be visible in broad daylight and would cast a shadow at night. This star is one of the greatest super-giant stars known.
"Albireo, the star at the head of the swan, is actually a beautiful double star, a yellow giant and a blue main-sequence star. You can just split this star with good binoculars held steady, and it looks better in a telescope.
"Then there's we come to the constellation of Aquila the Eagle. The bright star is Altair, and the two stars on either side of Altair are called the Pilot Stars. Altair is 16 light years away. It's about half again as big as our sun and nine times as bright. That shows how sensitive stars are to mass -- just a little more mass causes the star to burn much brighter.
"If you look with the binoculars you can find the two stars of Aquila's tail, then slide west (to the right) until they are at the far left of the field of view. To the far right of your field of view you can now see a fuzzy spot with a star at the center - you have found the Wild Duck Cluster. In a telescope this looks like a dense cluster of tiny stars broken into groups - the central group is V-shaped and looked to early observers like a flight of wild ducks - hence the name.
"Any questions?"
[Class Roster ]
Star maps: East | West | North | South | Overhead
There were some extra students for tonight's class, and when everyone gathered, Ellie reminded them. "We're being joined tonight by Veronica Mars and her photography class," she said. "They're going to be learning about night photography." Then she began the night's lecture:
"Three brilliant stars form the Summer Triangle, making it our best heavenly landmark in the summer night sky." She traced out the distinctive triangle with her laser pointed. "Vega, high above and its western point, appears the brightest of the three." Ellie's voice was especially wistful when talking about Vega. "Deneb, also high above and to the east of Vega, appears the dimmest. Altair shines below in the south, forming the most distant point of this great triad.
"These three stunning stars are an unofficial star group, or asterism, that link three constellations: Lyra, Cygnus the Swan, and Aquila the Eagle.
"You can't help but notice a really bright star that's almost straight up. That star is the renowned Vega. Vega is a zero magnitude star, about the same apparent brightness as Arcturus, and is the fifth brightest start in the sky. It is actually 25 light years away, nearly twice as far as Altair, three times the mass of the sun, and about 50 times as bright as the sun. Imagine having 50 suns in our sky. If Vega was our sun we'd be cooked.
"Vega is part of the constellation of Lyra the Lyre. It is easily recognizable as a parallelogram of four stars right next to the very bright Vega. This constellation represents a lyre, or harp, with Vega at the top of the lyre as one of the handles. The other handle must have broken off. The lyre belongs to Orpheus, and was given to him by his father, Apollo.
"M57, also known as the Ring Nebula, is one of the finest planetary nebula in the skies. It's also known as 'The Doughnut Nebula' in Japan. The central star, now a white dwarf, blew off a shell of gas as it died, creating the ring. It is about 2100 light years away, and while the naked eye cannot see the colors of the ring, processed images show the nebula has a bluish interior, yellow to white in the ring itself, and reddish colors in outer edge.
"The next constellation we reach is Cygnus the Swan. This constellation is also known as the Northern Cross and at Christmas time, in the evening, it has rotated across the sky so it is standing on its base on the northwestern horizon, with the bright star Vega next to it. Very Christmas-y.
"Deneb is the star at the tail of the Swan. Notice that it is about as bright as Altair, which is 16 light years away -- so how far would you guess Deneb is? As it happens... Deneb is 2600 light years away - about 150 times farther! Deneb is actually 20,000 times brighter than Altair and 200,000 times brighter than our sun. If Deneb were as close as Altair, it would be visible in broad daylight and would cast a shadow at night. This star is one of the greatest super-giant stars known.
"Albireo, the star at the head of the swan, is actually a beautiful double star, a yellow giant and a blue main-sequence star. You can just split this star with good binoculars held steady, and it looks better in a telescope.
"Then there's we come to the constellation of Aquila the Eagle. The bright star is Altair, and the two stars on either side of Altair are called the Pilot Stars. Altair is 16 light years away. It's about half again as big as our sun and nine times as bright. That shows how sensitive stars are to mass -- just a little more mass causes the star to burn much brighter.
"If you look with the binoculars you can find the two stars of Aquila's tail, then slide west (to the right) until they are at the far left of the field of view. To the far right of your field of view you can now see a fuzzy spot with a star at the center - you have found the Wild Duck Cluster. In a telescope this looks like a dense cluster of tiny stars broken into groups - the central group is V-shaped and looked to early observers like a flight of wild ducks - hence the name.
"Any questions?"
Re: Observe and chat amongst yourselves
Re: Observe and chat amongst yourselves
Re: Observe and chat amongst yourselves
Re: Observe and chat amongst yourselves
Re: Observe and chat amongst yourselves
Re: Observe and chat amongst yourselves
Re: Observe and chat amongst yourselves