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Posts Tagged ‘Deneb’

10/06/2015 – Ephemeris – Deneb our home-town star

October 6, 2015 Comments off

Ephemeris for Tuesday, October 6th.  The Sun will rise at 7:46.  It’ll be up for 11 hours and 27 minutes, setting at 7:14.   The Moon, 2 days past last quarter, will rise at 2:36 tomorrow morning.

We, here in Traverse City, Michigan have a pretty unique relation to the bright star Deneb, as is any location near 45 degrees north latitude.  Tonight at 9:23  Deneb will be three-quarters of a degree due north of the zenith.  Due north means that it’s on our meridian, a line you may remember from your school days.  For astronomers it passes from the north point on the horizon, through the overhead point or zenith to the south point on the horizon.  Also due to our latitude Deneb is circumpolar, meaning that it doesn’t quite set on a clean northern horizon.  Deneb and 56 other stars are used for celestial navigation, which is still taught in case the GPS system goes down due to solar or enemy action.

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

Addendum

Deneb nearly at the zenith

Deneb nearly at the zenith from Traverse City. Created using Cartes du Ciel.

Deneb nearly at the horizon

Deneb is close to the horizon due north. Created using Cartes du Ciel.

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08/04/2015 – Ephemeris – Is it a swan or a cross?

August 4, 2015 Comments off

Ephemeris for Tuesday, August 4th.  The Sun rises at 6:32.  It’ll be up for 14 hours and 32 minutes, setting at 9:04.   The Moon, 2 days before last quarter, will rise at 11:33 this evening.

High in the east northeast as it gets dark flies the constellation of Cygnus the swan.  This constellation is also known as the Northern Cross.  The cross is seen lying on its side with the bright star Deneb at the head of the cross to the left.  The rest of the cross is delineated in the stars to the right.  As a swan, Deneb is the tail, the stars of the crosspiece of the cross are part of the leading edges of the wings as Cygnus flies south through the Milky Way.  There are faint stars that also define the tips and trailing edges of its wings.  It is a very good portrayal of a flying swan, like the mute swans we see on the wing in our area.  This is the form the Greek god Zeus took to seduce the maiden Leda in the Leda and the swan affair, out of whose union Pollux was born, who was the twin of Castor, both of whom are also in the stars as the constellation Gemini.  In Cygnus we are looking toward the direction that the Sun and the Earth are traveling as we orbit the center of the Milky Way.

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

Addendum

CygnusTheSwan Created using Stellarium.

Cygnus The Swan Created using Stellarium.

Note for telescope owners:  The star that appears in the eye of the swan image above is Alberio (β Cygni), which splits into a beautiful binary star, whose component  stars are blue and gold.  It takes a bit more magnification than a pair of binoculars provides.

Note also the mythological citation in the program was omitted from the broadcast version due to time constraints.

07/27/2015 – Ephemeris – Deneb, the dimmest of the Summer Triangle stars. But is it really?

July 27, 2015 Comments off

Ephemeris for Monday, July 27th.  The Sun rises at 6:23.  It’ll be up for 14 hours and 51 minutes, setting at 9:14.   The Moon, 3 days past first quarter, will set at 3:36 tomorrow morning.

This evening when it gets dark the bright star Deneb in Cygnus the swan will be high  in the east northeast.  Deneb is the dimmest star of the summer triangle.  Of the other stars of the triangle, Vega is very high in the east, 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 100 times the distance of Vega.  If brought as close as Vega, Deneb would be almost as bright as the full moon.  It is as bright as two hundred thousand suns.  It apparently has run out of hydrogen in its core.  Once a blue super giant star, it’s currently evolving through the white supergiant stage.

Times 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.

Deneb & North American Nebula

One of my old photographs of Deneb and the North American Nebula digitized from a slide.

H-R diagram

The Hertzsprung-Russell diagram of star luminosity vs. surface temperature. Note that Deneb is at the top center, while the Sun is lower on the main sequence. Credit: European Southern Observatory (ESO).

07/16/2015 – Ephemeris – The Summer Triangle is the sign of the season

July 16, 2015 Comments off

Ephemeris for Thursday, July 16th.  Today the Sun will be up for 15 hours and 12 minutes, setting at 9:25.   The Moon, 1 day past new, will set at 9:32 this evening, and tomorrow the Sun will rise at 6:13.

We’re almost a month into summer, and the asterism or informal constellation called the Summer Triangle can be seen midway up the sky 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 is so far away that it’s distance is in some doubt and may be 2,600 light years away.

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

Addendum

Summer Triangle. Created using Stellarium.

Summer Triangle. Created using Stellarium.

07/09/2015 – Ephemeris – The first stars to appear at night

July 9, 2015 Comments off

Ephemeris for Thursday, July 9th.  Today the Sun will be up for 15 hours and 23 minutes, setting at 9:29.   The Moon, 1 day past last quarter, will rise at 2:05 tomorrow morning, and tomorrow the Sun will rise at 6:07.

Let’s check out all the bright stars in the evening sky, as it gets dark tonight.  Low in the west are the planets Venus and Jupiter.  High in the west is the bright yellow-orange star Arcturus.  In the northwest is the Big Dipper,  whose curved handle points to Arcturus.  Straightening that curve to a spike will point to Spica a blue-white star low in the southwest.  The planet Saturn is located in the south.  Below and left of it is the red star Antares which usually twinkles merrily.  High in the east is the bright white star Vega.  To its lower right is Altair, and to its lower left the star Deneb.  Vega, Altair and Deneb make the Summer Triangle, whose rising in the east signals the coming of summer.

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

Addendum

I talked about seeing the first stars a month ago.  It seems that in holding star parties this time of year we spend a lot of time watching the first stars appear.  I wanted to discuss the Summer Triangle, but it wandered off to what you see above.  I’ll get there next week, I promise.

Firsat stars to appear

The first stars and planets to appear. See if you can located them from the text. Created using Stellarium for about 10 p.m., July 9, 2015.

11/24/2014 – Ephemeris – The Summer Triangle is still with us

November 24, 2014 Comments off

Ephemeris for Monday, November 24th.  The sun will rise at 7:50.  It’ll be up for 9 hours and 16 minutes, setting at 5:07.   The moon, 2 days past new, will set at 7:29 this evening.

Well it’s almost Thanksgiving and about time that the Summer Triangle of bright summer stars finally set.  Except it won’t go just yet.  The stars Vega, Altair and Deneb are still hanging around in the west.  The bright summer part of the Milky Way is gone.  The constellations the three stars are in are Altair in Aquila the Eagle, now flying vertically up,  Deneb in Cygnus the swan flying vertically down, and Vega in Lyre the harp, lying on its side.  Altair the southernmost of these three will set first, later Vega will also set.  What happens to Deneb depends on your location in the Interlochen Public Radio area.  It you are north of Traverse City, Deneb will not actually set over Lake Michigan’s northern horizon.

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

Addendum

Summer Triangle

The Summer Triangle at 9 p.m. on November 24, 2014. Created using Stellarium.

Vega Setting

Vega near its setting point at 11:07 p.m. p.m. on November 24, 2014. Created using Stellarium.

Deneb near setting?

Deneb near its setting point at 5:05 a.m. p.m. on November 25, 2014. Created using Stellarium.

But will Deneb really set for Traverse City.  Geometrically it will.  However with a flat northern horizon looking northward over the bays to a clean Lake Michigan horizon, atmospheric refraction will bend the light from Deneb making it appear higher in the sky than it really is, so it won’t actually set.  On the other side atmospheric extinction, the dimming of stars close to the horizon due to the filtering effect of looking through so much atmosphere would make Deneb impossible to see without a telescope.  It might be an interesting challenge to spot.

07/18/2014 – Ephemeris – Deneb is the brightest star of the Summer Triangle… Really

July 18, 2014 Comments off

Ephemeris for Friday, July 18th.  Today the sun will be up for 15 hours and 8 minutes, setting at 9:22.   The moon, at last quarter today, will rise at 12:58 tomorrow morning.  Tomorrow the sun will rise at 6:15.

At 11 this evening the bright star Deneb in Cygnus the swan will be moderately high in the east northeast.  Deneb is the dimmest star of the summer triangle.  Of the other stars of the triangle, Vega is nearly overhead, and Altair to the southeast.  While Deneb’s apparent magnitude, or brightness as seen from Earth, makes it the dimmest of the three bright stars, Deneb has a vast distance of possibly 1,550  light years.  If brought as close as Vega, Deneb would be several times brighter than Venus.  For all this it is only 13-20 times the mass of the sun.  It will have an extremely short life and will explode, go supernova, in perhaps a few million years.  Closer to home, check out the Sun at Kingsley Heritage Days This Saturday and Sunday.

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

Addendum

Northern Cross

Deneb and the Northern Cross section of Cygnus the swan. Created using Stellarium.

Deneb & North American Nebula

One of my old photographs of Deneb and the North American Nebula digitized from a slide.

The North American Nebula, visible as a faint smudge in binoculars or the naked eye may be ionized and illuminated by Deneb.  It’s distance appears to be comparable to that of Deneb.

You may note that previous postings about Deneb over the years have given different distances of Deneb.  That just denotes how difficult it is to pin down its distance.