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Posts Tagged ‘Summer Triangle’

11/13/2018 – Ephemeris – The Summer Triangle in autumn

November 13, 2018 Comments off

Ephemeris for Tuesday, November 13th. The Sun will rise at 7:37. It’ll be up for 9 hours and 39 minutes, setting at 5:16. The Moon, 2 days before first quarter, will set at 10:20 this evening.

The Summer Triangle is still in the sky at 9 p.m., even though it’s November. These three bright stars that straddle the Milky Way are high in the east for most of the summer, move overhead and begin to slide to the west in autumn. We will lose Altair, the southernmost of the three stars at 9 p.m. on the winter solstice, December 21st. We’ll lose the brightest, Vega in January. For the northern half of the IPR listening area the northernmost of the triangle stars, Deneb won’t quite set below a north Lake Michigan horizon. Next spring we’ll be waiting and watching for these three stars to rise, reclaim the skies, and bring again the warm summer skies. The winter skies do however have more bright stars than the summer sky.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Summer Triangle tonight
The Summer Triangle of the three bright stars Vega, Deneb and Altair is still high in the west at 8 p.m. tonight. The zenith is near the top of the image. Created using Stellarium
Summer Triangle about to set.
The Summer Triangle with Altair about to set on the winter solstice at 9 p.,. Created using Stellarium.
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09/10/2018 -Ephemeris – The Coathanger in the sky

September 10, 2018 Comments off

Ephemeris for Monday, September 10th. The Sun will rise at 7:15. It’ll be up for 12 hours and 47 minutes, setting at 8:02. The Moon, 1 day past new, will set at 8:57 this evening.

Just about every amateur astronomer knows a little asterism or informal constellation called the Coathanger. It’s stars are mostly below naked eye visibility, but it is a great sight in binoculars. It’s located along a line from Altair in Aquila the eagle to Vega in Lyra the harp. These are two star of the Summer Triangle. It is also just west of, or right of, the constellation Sagitta the arrow. It consists of six stars in just about a perfectly straight line with four stars in a tight group south of them making the hook. In telescope finders which invert the image the Coathanger appears right-side-up. Arab astronomer Al Sufi discovered it and described it in 964 AD. It has the catalog designation of Collinder 399. It is also known as Brocchi’s Cluster.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Coathanger finder animation

How to find the Coathanger. Look for the Summer Triangle. On the line from Altair to Vega the Coathanger can be found. Star imaged by Bob Moler.

Binocular view of the Coathanger

Binocular view of the Coathanger. From the original resolution of the above photograph.

Telescope finder view of the Coathanger

Telescope finder view of the Coathanger. Telescope finders usually invert the image, so it looks like a proper coat hanger.

09/06/2018 – Ephemeris – The constellations of Delphinus and Sagitta

September 6, 2018 Comments off

Ephemeris for Thursday, September 6th. The Sun will rise at 7:11. It’ll be up for 12 hours and 59 minutes, setting at 8:10. The Moon, 3 days before new, will rise at 4:19 tomorrow morning.

Located below the eastern edge of the Summer Triangle of three of the brightest stars in the sky, which is nearly overhead in our sky at 10 p.m., is the tiny constellation of Delphinus the dolphin. Delphinus’ 6 stars in a small parallelogram with a tail, really does look like a dolphin leaping out of the water. The parallelogram itself has the name Job’s Coffin. The origin of this asterism or informal constellation is unknown. Of the dolphin itself: the ancient Greeks appreciated this aquatic mammal as we do, and told stories of dolphins rescuing shipwrecked sailors. There’s another tiny constellation to the right of Delphinus, Sagitta the arrow a small thin group of 5 stars, which represents Cupid’s dart.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Delphinus and Sagitta finder animation

Delphinus and Sagitta finder animation. Click on image to enlarge. Created using Stellarium and GIMP.

07/02/2018 – Ephemeris – The starry triangle of summer

July 2, 2018 Comments off

Ephemeris for Monday, July 2nd. Today the Sun will be up for 15 hours and 30 minutes, setting at 9:31, and it will rise tomorrow at 6:02. The Moon, half way from full to last quarter, will rise at 12:19 tomorrow morning.

Now that it’s summer it’s time to look for the Summer Triangle in the sky. It’s seen rising in the east as it gets dark. Highest of the three bright stars is Vega in the constellation Lyra the harp, whose body is seen in a narrow parallelogram nearby. The second star of the triangle is Deneb lower and left of Vega, It appears dimmer than Vega because it is by far the most distant of the three. The third star of the Summer Triangle is seen farther below and a right of Vega. It is Altair in Aquila the eagle, and the closest. Altair is 16.5 light years away, Vega is 27 light years while Deneb actually one of the brighter stars known, is 1500 or more light years away. It’s distance is not well known.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The Summer Triangle July 5, 2012 at 11 p.m. Created using Stellaruim and The Gimp.

The Summer Triangle. Created using Stellarium.

5/15/2018 – Ephemeris – Two thirds thru spring

May 15, 2018 Comments off

Ephemeris for Tuesday, May 15th. Today the Sun will be up for 14 hours and 49 minutes, setting at 9:04, and it will rise tomorrow at 6:13. The Moon is new today, and won’t be visible.

Here we are at the middle of May, nearly two-thirds through spring and in the west only a few winter stars remain. Castor and Pollux of Gemini are horizontal in the west, Procyon the Little Dog Star is below and left of them, Capella in Auriga is in the northwest, but for most of the IPR listening area it will never quite set. At 10:30 Betelgeuse in Orion the hunter will be setting, chased from the skies by Scorpius the scorpion, which is rising in the southeast. In one story it is the sting of this scorpion that killed him. Already at that time two-thirds of the stars of the summer Triangle are up. Bright Vega in Lyra the harp, and Deneb in Cygnus the swan. The Big Dipper reigns overhead as spring is in full bloom.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Goodbye winter, hello summer

The sky dome for 10:30 p.m. May 15, 2018 showing the stars and constellations. It may not work for any latitude or time, but it works for our location, near 45 degrees north. Created using Stellarium.

07/17/2017 – Ephemeris – Constellations of the Summer Triangle III: Aquila the Eagle

July 17, 2017 Comments off

Ephemeris for Monday, July 17th. Today the Sun will be up for 15 hours and 9 minutes, setting at 9:23, and it will rise tomorrow at 6:14. The Moon, 1 day past last quarter, will rise at 2:08 tomorrow morning.

Aquila the eagle is a constellation that lies in the Milky Way. It’s in the southeastern sky as it gets dark. Its brightest star, Altair is one of the stars of the Summer Triangle, the group of three bright stars dominating the eastern sky in the evening now. Altair, in the head of the eagle, is flanked by two slightly dimmer stars, the shoulders of the eagle. The eagle is flying northeastward through the Milky Way. Its wings are seen in the wing tip stars. A curved group of stars to the lower right of Altair is its tail. Within Aquila the Milky Way shows many dark clouds as part of the Great Rift that splits it here. The other summer bird is Cygnus the swan above and left of Aquila, flying in the opposite direction.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The Summer Triangle July 5, 2012 at 11 p.m. Created using Stellaruim and The Gimp.

The Summer Triangle. Created using Stellarium and The Gimp.

Aquila finder animation

Animated Cygnus finder chart. Created using Stellarium.

07/13/2017 – Ephemeris – Constellations of the Summer Triangle I: Lyra the harp

July 13, 2017 1 comment

Ephemeris for Thursday, July 13th. Today the Sun will be up for 15 hours and 16 minutes, setting at 9:26, and it will rise tomorrow at 6:10. The Moon, 3 days before last quarter, will rise at 12:02 tomorrow morning.

Very high up in the eastern sky at 11 p.m. can be found a bright star just above a small, narrow, but very distinctive parallelogram of stars. They are the stars of the constellation Lyra the harp. The bright star is Vega, member of the Summer Triangle and one of the twenty one brightest first magnitude stars. Vega is actually the 5th brightest night-time star. The harp, according to Greek mythology, was invented by the Greek god Hermes. The form of the harp in the sky, is as he had invented it: by stretching strings across a tortoise-shell. Hermes gave it to his half-brother Apollo, who in turn gave it to the great musician Orpheus. The Sun’s motion with respect to most stars around it is towards the vicinity of Lyra.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The Summer Triangle July 5, 2012 at 11 p.m. Created using Stellaruim and The Gimp.

The Summer Triangle. Created using Stellarium.

Annimated Lyra finder chart

Animated Lyra finder chart. The lyre image not supplied by Stellarium but is from The World’s Earliest Music by Hermann Smith, a Project Gutenberg E book, figure 60, captioned “The Chelys or Greek Tortoiseshell Lyre”. Image created using Stellarium and GIMP.