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Posts Tagged ‘Vega’

08/19/2019 – Ephemeris – The dimmest looking star of the Summer Triangle is by far the brightest

August 19, 2019 Comments off

Ephemeris for Monday, August 19th. Today the Sun will be up for 13 hours and 52 minutes, setting at 8:42, and it will rise tomorrow at 6:50. The Moon, half way from full to last quarter, will rise at 10:53 this evening.

This evening when it gets dark the bright star Deneb in Cygnus the swan will be very high in the east. Deneb is the dimmest star of the summer triangle. Of the other stars of the triangle, Vega is higher nearly overhead, while Altair is lower in the southeast. While Deneb’s apparent magnitude, or brightness as seen from Earth, makes it the dimmest of the three bright stars, Deneb’s vast distance of possibly 2,600 light years* makes it over 90 times the distance of Vega. If brought as close as Vega, Deneb would be as bright at least as the quarter moon. It is possibly as bright as 196 thousand suns; and a huge star, possibly as large in diameter as the orbit of the Earth. For all this it is only 20 to 25 times the mass of the Sun.

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

Addendum

Great Rift in the Summer Triangle

The Great Rift finder animation as seen in the Summer Triangle, also showing the constellations of Cygnus the swan and the the northern part of Aquila the Eagle. This image a stack of 5 30 second exposures taken the morning of the Perseid meteor shower last year in a vain attempt to capture some meteors.

07/08/2019 – Ephemeris – The bright star Vega

July 8, 2019 Comments off

Ephemeris for Monday, July 8th. Today the Sun will be up for 15 hours and 24 minutes, setting at 9:29, and it will rise tomorrow at 6:06. The Moon, 1 day before first quarter, will set at 1:31 tomorrow morning.

The bright star high in the east is Vega, one of the stars of the Summer Triangle an informal constellation called an asterism. Vega belongs to the official constellation Lyra the harp, which includes a narrow parallelogram of stars to its south. Vega is regarded by astronomers as a standard calibration star. Though a first magnitude star, its actual magnitude is 0.03. It is a type A0 a pure white star, and is 25 light years away. Astronomers however got a shock in 1983 when calibrating the Infrared Astronomy Satellite (IRAS) on it: Vega showed an excess of Infrared radiation which means the star is orbited by a disk of dust, perhaps a Kuiper belt of its own. Due to the slow wobble of the earth’s axis Vega will become our pole star in about 14 thousand years.

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.

Vega - Alpha Lyrae

Vega: Comparison to the Sun and its dust ring. Credit Orange County Astronomers.

06/20/2019 – Ephemeris – Hercules wuz robbed!

June 20, 2019 Comments off

Ephemeris for Thursday, June 20th. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:31, and it will rise tomorrow at 5:57. The Moon, 3 days past full, will rise at 12:12 tomorrow morning.

Orion, the hard luck mythological Greek hunter gets a splashy constellation in the winter sky, but the greatest hero of all, Hercules, gets a dim group of stars on the border between the spring and summer stars. At 11 p.m. Hercules is high in the southeast. It is located above and right of the bright star, Vega in the east. Hercules’ central feature is a keystone shaped box of stars, called the Keystone, which represents the old boy’s shorts. From each top corner extend lines of stars that are his legs, from the bottom stars, the rest of his torso and arms extend. So in one final indignity he’s upside down in our sky. Some see him crouched down, club upraised holding the Hydra about to throttle it. For those with a telescope it contains the beautiful globular star cluster M13.

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

Addendum

Hercules finder

Hercules animation showing neighboring stars at 11 p.m. for mid June, Click on image to enlarge. Created using Stellarium and GIMP.

Stars and M13 vusuble in Binoculars in the Keystone of Hercules

Stars and M13 (Great Star Cluster in Hercules) visible in binoculars in the Keystone of Hercules. Click in the image to enlarge. Created using Stellarium.

M13

M13, the Great Globular Star Cluster in Hercules. It takes a telescope with an aperture (diameter) of 6 inches (150 mm) to begin the resolve the stars in it. Credit: Scott Anttila

 

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.

07/16/2018 – Ephemeris – Lyra the harp, Hermes’ invention

July 16, 2018 Comments off

Ephemeris for Monday, July 16th. Today the Sun will be up for 15 hours and 12 minutes, setting at 9:24, and it will rise tomorrow at 6:13. The Moon, 3 days before first quarter, will set at 12:02 tomorrow morning.

Very high up in the eastern sky at 11 p.m. can be found a bright star just north of a small, narrow, but very distinctive parallelogram of stars. They are the stars of the constellation Lyra the harp. The bright star is Vega, 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 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 has a motion with respect to most stars around it. Its direction 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.

Addenda

Annimated Lyra finder chart

Animated Lyra finder chart. with Vega and the other named stars of the Summer Triangle. The lyre image not supplied by Stellarium but is from The World’s Earliest Music by Hermann Smith, Figure 60, A Project Gutenberg Ebook, and captioned “The Chelys or Greek Tortoiseshell Lyre”. Click on the image to enlarge Created using Stellarium and GIMP.

Last Saturday night’s wild Sun ‘n Star Party

Last Saturday night the Grand Traverse Astronomical Society, myself included, and the rangers and volunteers of the Sleeping Bear Dunes National Lakeshore held our Sun ‘n Star Party at the Dune Climb.  I live 20 miles southeast of the Dune Climb, and about half way between Traverse City and Interlochen.  It’s also the location for which the Ephemeris sunrise and sunset times are calculated for.  We rely on the GOES East satellite imagery to show us the cloud patterns and movement.  Saturday morning was pretty overcast and hot.  GOES East showed that a big clearing was heading for us.  At 1 p.m. I emailed our members that the event was a GO, and began to pack up the car with my two telescopes, and assorted items.  Meanwhile some raindrops were showing up on the windshield.  A check with weather radar on my phone confirmed that some rainstorms were popping up between my location and Lake Michigan.  This is rather normal when it’s hot and humid in the afternoon, and wouldn’t affect the Dune area close to the lake.  In driving to the Dune Climb I drove through some rain showers, but the skies cleared by the time I got within 5 miles from the lake.

The solar observing from 4 to 6 p.m.was great, except for no sunspots.  We had 2 solar telescopes that did reveal some prominences.  The sky was clear.  The storm clouds were receding to the east.  Of course we couldn’t see much to the west because the dune was in the way.  Its angular altitude averaged 12 degrees.  Some of us stayed there and ate our dinner.  By 7:30 the wind came up from the southwest.  A check of the GOES East satellite showed us a large, roughly square cloud the width of the lake slowly moving northward that was just south of us.  Just after 8 p.m. we noticed clouds looming from the south, then fog was overtaking the tops of the dunes to the southwest.  Shortly thereafter we were socked in.  At a little after 9 p.m. Marie Scott the ranger in charge of this event gave introductions, and handed the microphone to me, who introduced our members and went over what we were supposed to see that night.  We couldn’t track this cloud anymore by satellite because it was between the daytime color imagery and the nighttime infrared imagery.  However around 10 p.m. someone spotted Vega, nearly overhead.  And while I was swinging my 11″ Dobsonian towards it, someone else called out Jupiter.  Looking around the fog was lifting.  The night was salvaged.  We stayed over an hour after the official 11 p.m. to watch Mars rise near the end of the star party, and finally view some of the wonders of the dark summer sky.

This was the fourth of seven monthly star parties scheduled at the Dunes this year.  It was the first we didn’t cancel due to weather.  We generally cancel one or two of then a year, but to start the year with three was depressing.

 

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.