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Posts Tagged ‘Vega’

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.

 

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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.

07/13/2017 – 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.

06/29/2017 – Ephemeris – A closer look at the star Vega

June 29, 2017 1 comment

Ephemeris for Thursday, June 29th. Today the Sun will be up for 15 hours and 31 minutes, setting at 9:31, and it will rise tomorrow at 6:00. The Moon, 1 day before first quarter, will set at 1:21 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 pure white star, and is 27 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 that 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 be our pole star in 14 thousand years.

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

Addendum

Lyra

Magnified view of Lyra. Created using Stellarium.

Vega

Vega in the mid-infrared from the Spitzer Infrared Satellite. Credit: NASA/JPL-Caltech/University of Arizona.

Categories: Ephemeris Program, stars Tags: ,

06/27/2017 – Ephemeris – Arcturus as a look at the Sun’s future

June 27, 2017 1 comment

Ephemeris for Tuesday, June 27th. Today the Sun will be up for 15 hours and 32 minutes, setting at 9:31, and it will rise tomorrow at 5:59. The Moon, 3 days before first quarter, will set at 12:18 tomorrow morning.

With the Moon brightening the night sky, let’s take a look at the star Arcturus, which with its pointer, the curve of the Big Dipper’s handle is slipping into the high western sky. Arcturus is the 4th brightest night time star, though some think the star Vega, high in the east is brighter. They are different colors because Arcturus is orange, while Vega is whiter than the Sun. Arcturus is a preview of what the Sun will become in four or five billion years from now. It is only 10% more massive than the Sun and is that much older than the Sun, so it is turning into its red giant stage, after running out of hydrogen to turn into helium in its core to produce energy. The helium is now compressing and heating to begin its reaction.

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

Addendum

Arcturus finder chart

Arcturus finder chart with the Big Dipper and Vega as guide posts. Created using Stellarium.

Here’s one of my prior posts about Arcturus, about its great space velocity:  https://bobmoler.wordpress.com/2016/04/26/04262016-ephemeris-arcturus-just-passing-through/

06/26/2017 – Ephemeris – Latest sunset and the apparent positions of the Summer Triangle stars

June 26, 2017 1 comment

Ephemeris for Monday, June 26th. Today the Sun will be up for 15 hours and 32 minutes, setting at 9:31, and it will rise tomorrow at 5:59. The Moon, 3 days past new, will set at 11:40 this evening.

Tonight we have the latest sunset of the year. From now on until December sunsets will become earlier. Other than the sunrise and sunset numbers, we’ll begin to notice it for real in a few weeks. At first that realization strikes me a sad note that summer is beginning to end. However the astronomer in me realizes that means more night-time hours, and that the summer Milky Way is coming. Of the three bright stars of the Summer Triangle overhead and in the east, two of its stars are in the milky band. They are Deneb to the north and Altair to the south. Vega, closest to the zenith is not in the band. Actually all the stars we see with the naked eye or small telescopes belong to the Milky Way galaxy.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The constellations Lyra, Cygnus and Aquila

Looking at the stars of the Summer Triangle and their location in and near the Milky Way band. Created using Stellarium.