08/26/2016 – Ephemeris – Friday Night Live tonight, Star Party tomorrow

August 26, 2016 Leave a comment

Ephemeris for Friday, August 26th.  The Sun rises at 6:58.  It’ll be up for 13 hours and 30 minutes, setting at 8:29.  The Moon, 2 days past last quarter, will rise at 2:10 tomorrow morning.

The Grand Traverse Astronomical Society finishes off August with another busy weekend.  Tonight the society members will bring their telescopes to downtown Traverse City and Friday Night Live, staying after to view the planets Saturn and Mars if it’s clear.  Saturn’s rings are, of course, spectacular.  Tomorrow night society members will be at Northwestern Michigan College’s Rogers Observatory beginning at 9 p.m. for a star party viewing of the planets, especially Saturn.  That later as it gets really dark, the summer Milky Way will appear with its great telescopic treasures.  Tomorrow, right after sunset the planets Venus and Jupiter will appear very close together.  Observers far south of us will have a better shot at it than we do.

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

Addendum

Venus near Jupiter

Venus near Jupiter at 9 p.m., or a half hour after sunset, August 27, 2016. I doubt if you could see the Jovian satellites against the bright twilight. It all but requires a big lake or ocean horizon, or a location far south of northern Michigan to raise these planets higher in the sky. Created using Stellarium.

08/25/2016 – Ephemeris – Sagittarius, a very strange archer

August 25, 2016 Leave a comment

Ephemeris for Thursday, August 25th.  The Sun rises at 6:57.  It’ll be up for 13 hours and 33 minutes, setting at 8:31.  The Moon, 1 day past last quarter, will rise at 1:18 tomorrow morning.

Low in the south at 11 p.m. lies the constellation of Sagittarius.  The name means archer, but this isn’t just any old fellow with a bow and arrow.  It’s a centaur with a bow and arrow.  These half man half horse creatures were a rowdy bunch; kind of the ancient Greek counterpart of a motorcycle gang.  The one exception is this centaur, Chiron by name.  He was highly educated, and learned medicine from the great physician Aesculapius, whom we see in the sky to the upper right as the constellation Ophiuchus. His drawn bow and arrow can also be seen in the stars here, pointing to Scorpius the scorpion’s heart.  If it’s hard seeing a Centaur here don’t be disappointed.  To most of us the constellation looks like a stout little teapot.

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

Addendum

Sagittarius and Scorpius

Sagittarius taking aim at Scorpius with Mars and Saturn at 10 p,m. August 25, 2016. Created using Stellarium.

Sagittarius actual star field

Actual Sagittarius star field where the Teapot is easily seen. Credit Bob Moler.

“I’m a little teapot short and stout…” Children’s song.

08/24/2016 – Ephemeris – Planets gather into two groups this evening

August 24, 2016 Leave a comment

Ephemeris for Wednesday, August 24th.  The Sun rises at 6:56.  It’ll be up for 13 hours and 36 minutes, setting at 8:32.  The Moon, at last quarter today, will rise at 12:31 tomorrow morning.

Tonight we still have all the bright classical planets in the evening sky, barely.  Mercury, Venus and Jupiter are very low in the west and will set at 9:08, 9:24 and 9:29 p.m. respectively.  Saturday evening, right after sunset, Venus will be passing very close to Jupiter while they are low in the west, well within a low power telescope field.  Mars, Saturn and the star Antares start the evening in the southwestern sky in a nearly perfect line.  Antares, whose name means Rival of Mars is On the bottom with brighter Mars just above it, with Saturn above.  Mars, moving rapidly to the east against the stars will set at 12:15 a.m.  Saturn, spectacular in telescopes with its rings, will set at 12:39 a.m.

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

Addenda

The Planets Tonight

Jupiter, Venus, Mercury

Looking very low in the west at 9 p.m., 28 minutes after sunset, August 24, 2016. For scale, Jupiter is a bit less than 5 degrees above the horizon, Mercury a bit lass than 2. Created using Stellarium.

Saturn, Mars and Antares

Mars breaks out the Saturn-Antares lineup at 9:30 p.m., August 24, 2016. Created by Stellarium.using Stellarium.

Saturn and its moons

Saturn and some of its moons at 9:30 p.m. August 24, 2016. Created using Cartes du Ciel (Sky Charts).

Planets and Moon on a single night

Planets at sunset and sunrise of a single night starting with sunset on the right on August 24, 2016. The night ends on the left with sunrise on August 25. Actually all the naked eye planets are in the evening sky. If you are using Firefox right-click on the image and select View Image to enlarge the image. That goes for all the large images. Created using my LookingUp program.

Mars, Antares and Saturn Last Night

Saturn, Mars and Antares

Saturn, Mars and Antares and the setting Scorpius to the right of the tree, and the Sagittarius Teapot with the Milky Way boiling out of the spout at 11:03 p.m. EDT, August 24, 2016. Credit Bob Moler from my back yard.

08/23/2016 – Ephemeris – Mars, Antares and Saturn line up

August 23, 2016 1 comment

Ephemeris for Tuesday, August 23rd.  The Sun rises at 6:55.  It’ll be up for 13 hours and 39 minutes, setting at 8:34.  The Moon, 1 day before last quarter, will rise at 11:49 this evening.

Tonight if you look out to the southwest, you will see a nearly perfect, nearly vertical line of bright stars.  But two of these are planets.  The brightest is the red planet Mars.  Below is it’s rival, the red giant star Antares.  Above is the ringed planet Saturn.  Tonight Mars will be just to the right of the Saturn Antares line.  After they set tonight and before we see them tomorrow night Mars will have moves  to be just out of the line to the left.  I hope it’s clear tonight so I can get a picture of them.  A digital camera on a tripod with a low f-stop, and a high ISO speed with a shutter open for maybe 15 seconds ought to do it.  Manually focus on infinity.  Dark skies confuse auto focusers.  And turn the flash off.  Try it again tomorrow night.

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

Addendum

Mars approaching Antares

Animation of Mars approaching Antares from August 4 to the 24th, 2016 at 10 p.m. Created using Stellarium and GIMP.

The lineup is forming. Saturn, Mars and Antares at 10:20 p.m., August 22, 2016.  The globular cluster M 4 is also barely visible.Credit:  Bob Moler.

The lineup is forming. Saturn, Mars and Antares at 10:20 p.m., August 22, 2016. The globular cluster M 4 is also barely visible. Credit: Bob Moler.

75 mm focal length, 5 Seconds, F/4, ISO 6400

08/22/2016 – Ephemeris – The glorious summer Milky Way

August 22, 2016 Leave a comment

Ephemeris for Monday, August 22nd.  The Sun rises at 6:54.  It’ll be up for 13 hours and 42 minutes, setting at 8:36.  The Moon, 2 days before last quarter, will rise at 11:11 this evening.

We’ll get a bit of darkness tonight, but it will be the start of about two weeks of the best sky viewing of the year.  Now is the time the summer Milky Way is displayed to its fullest to the southern horizon.  City folk come to our area and are sometimes fooled by the brightness and expanse of the Milky Way and think it’s clouding up.  Yes those are clouds indeed, but they are star clouds.  Binoculars will begin to show them to be millions of stars, each too faint to be seen by themselves to the unaided eye, but whose combined glow give the impression of a luminous cloud.  Binoculars are the ideal tool to begin to explore the Milky Way.  Objects still too fuzzy can be checked out with a telescope to reveal their true nature.

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

Addendum

Milky Way

The Milky Way from the Sleeping Bear Dunes last August by Mark Stewart.

Note that this photo shows the Milky Way as brighter and with more stars than you’d see with the naked eye.

Ephemeris Extra – Sightseeing around the Summer Triangle

August 21, 2016 Comments off
Deep-Sky treasures around the Summer Triangle

The Summer Triangle and some Deep-Sky treasures within and nearby. Created using Cartes du Ciel (Sky Charts).

Published in the Grand Traverse Astronomical Society’s August 2016 Stellar Sentinel Extras section, updated from an article first published in 1998

One of the signs that summer is here is the appearance of the Summer Triangle in the evening sky. Three of the brightest stars of summer are arranged in a large beautiful triangle. The Summer Triangle isn’t an official constellation. It is an informal one, which is called an asterism. The Big Dipper is another famous asterism.

Each of the triangle stars belongs to its own separate constellation. At the top of our chart is Deneb, the dimmest of the three in our sky at magnitude +1.25. However it is actually the brightest of the three. It suffers only due to its distance of 2,600 light years. Its absolute magnitude, its magnitude if it were 10 parsecs or 32.6 light years away, is -8.4, as bright as the quarter moon. Deneb is situated at the tail of the Cygnus the swan. The word Deneb means tail. It’s actually part of a longer Arabic phrase the means “Tail of the Hen”.

Brightest from our point of view is Vega in Lyra the harp. Vega means either “Falling Eagle” or “Falling Vulture”. Vega is close to the sun, at 25 light years. It’s apparent magnitude is +0.03, with an absolute magnitude of +0.5.

Closest of the three is Altair in Aquila the eagle which is only 16.7 light years away, at magnitude +0.77 with an absolute magnitude of +2.2.  It spins rapidly, once in 8.9 hours, creating a decidedly oblate shape with an equatorial radius of 2 times the Suns radius and a polar radius of 1.6 times.

The area in and around the Summer Triangle is a wonderful hunting ground for a telescope. They include binary stars and deep sky objects.
Alberio, the star at the beak of Cygnus the swan is a beautiful maize and blue pair, which I have dubbed the “U of M Star” (University of Michigan’s Maize and Blue) at the public viewing nights. Sorry State fans, I don’t know of a green and white binary.  It’s a wide pair, but requires more than a pair of binoculars.

Another neat binary star is Epsilon Lyrae, just to the left of Vega. It shows as a wide pair of equally bright stars in binoculars. A telescope reveals, upon close inspection, that each is again a bin ary. Epsilon Lyrae is the famous double-double star, And splitting them is a good test of telescope and atmospheric seeing.

Just about centered between the two stars at the south end o f the parallelogram of Lyra can be found one of the really special faint wonders of the sky. It is M57, 57th object of Charles Messier’s list of objects that look like comets but aren’t. It is better known as the Ring Nebula. It is one of a class of objects known as planetary nebulae. Planetary nebulae have nothing to with planets, but many of them look like Uranus or Neptune, being faint small greenish or bluish in color. Anyway, the ring, and all planetaries are the result of the SlimStar™ plan of rapid mass loss. It is something small stars like the Sun do when out of fuel and are in the final collapse to white dwarfhood. The outer layers of the star are pushed out to form many wonderful shapes. The Ring Nebula apparently is a torus about half a light year in diameter and about 2,300 light years away. Though small and bright in telescopes, it is invisible in finder telescopes.   See the Hubble image of it on page E-4.

Another planetary is M27, also known as the Dumbbell Nebula is located just north of the tip star of Sagitta the arrow. This is a tough one to find, and like M57 is invisible in finders. The Dumbbell is large, but with a low surface brightness. The two glowing lobes of gas first visible give the object its name. Much finer detail is visible to the careful observer. It’s distance is thought to be about 1,360 light years, which makes its diameter nearly 3 light years.

The greatest globular star cluster in this area is M13 the Great Hercules Globular Star Cluster which is located along the western edge of the ‘Keystone’ part of Hercules. The fuzzy blob that is visible in binoculars and small telescopes begins to resolve itself into stars in telescopes of 6 inch diameter and larger. M13 contains upwards of a million stars packed in a diameter of 168 light years and is located some 22,200 light years away. Globulars are ancient clusters that trace there origins to the formation of the Milky Way.  Other globulars in this area are M92, also in Hercules, M56 in Lyra, M14 in Ophiuchus, the serpent bearer, M15 in Pegasus, and perhaps M71 in Sagitta the arrow. M71 may be a sparse globular or very compact galactic cluster.

Galactic or open clusters here are M11, off the tail of Aquila the eagle, M39 and M29 in Cygnus. M11, which is actually in Scutum the shield is among the finest of its type. It takes a telescope of 6 inches diameter to completely resolve it.  M11 is also called the Wild Duck Cluster, perhaps due to its vaguely triangular appearance.

The Summer Triangle provides a wealth of objects to view and study, Some are among the finest of all the heavens.

 

08/19/2016 – Ephemeris – Two astronomy outreach events tonight and tomorrrow

August 19, 2016 Comments off

Friday, August 19th.  The Sun rises at 6:50.  It’ll be up for 13 hours and 50 minutes, setting at 8:41.  The Moon, 1 day past full, will rise at 9:29 this evening.

August is a busy month for the Grand Traverse Astronomical Society with events every weekend.  Tonight the society members will bring their telescopes to downtown Traverse City and Friday Night Live, staying after to view the planets Saturn and Mars if it’s clear.  Saturn’s rings are, of course , spectacular.  Tomorrow night society members will be at the Kingsley Library for a twilight talk beginning at 8 p.m. followed by a star party in their parking lot.  The twilight talk will introduce the telescope that’s being donated to the library by the society.  The telescope is a small, simple to use table top model with a four and a half-inch aperture, great for viewing the Moon, bright planets and the wonders of the deep sky.

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

Addendum

White light viewing of the Sun

Viewing the Sun with a while light filter at Friday Night Live using Ron Uthe’s telescope at Friday Night Live. Credit Bob Moler

Saturn in the 2013 Friday Night Live

Ron Uthe (with the beard) explains that his telescope is pointed to Saturn in the 2013 Friday Night Live. Credit mine.

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