Archive
09/16/2016 – Ephemeris – The Harvest Moon is slightly eclipsed for everyone but the Americas
Ephemeris for Friday, September 16th. The Sun will rise at 7:23. It’ll be up for 12 hours and 27 minutes, setting at 7:50. The Moon, at full today, will rise at 7:59 this evening.
Tonight’s full Moon is the Harvest Moon, the nearest full Moon to the autumnal equinox. For the next few nights the Moon will rise later each night by much less than the average 50 minutes later each night effectively lengthening twilight for those gathering in crops. Also this afternoon there will be a penumbral lunar eclipse visible, well not here in Michigan… because the Moon won’t be up. Actually just about the whole world except North America and most of South America will be able to see the eclipse. A penumbral eclipse is what I call a 5 o’clock shadow eclipse. You wouldn’t know it unless someone pointed it out to you, when the Moon dips into the Earth’s outer shadow and the sunlight falling part of it is diminished by a little bit.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The not so full Moon of Monday night and its reflection on the waters of Suttons Bay after the schooner Inland Seas docked after an evening sail. Credit: the author.
The penumbral eclipse of the Moon centered on 2:25 p.m. Eastern time, 18:54 UT, for an hour and a half before and after. Only near the middle of the eclipse will anything be visible of the effect. I find that wearing sunglasses reduces the brightness of the moon and enhances the penumbral shadow. Credit: NASA/GSFC/ Fred Espenak.
For the full-page pdf of the above click here: http://eclipse.gsfc.nasa.gov/LEplot/LEplot2001/LE2016Sep16N.pdf
08/23/2016 – Ephemeris – Mars, Antares and Saturn line up
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
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.
75 mm focal length, 5 Seconds, F/4, ISO 6400
08/22/2016 – Ephemeris – The glorious summer Milky Way
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
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
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.
08/17/2016 – Ephemeris – Two groups of evening planets are visible
Ephemeris for Wednesday, August 17th. The Sun rises at 6:48. It’ll be up for 13 hours and 56 minutes, setting at 8:44. The Moon, 1 day before full, will set at 7:01 tomorrow morning.
Tonight we still have all the bright classical planets in the evening sky. Mercury, Venus and Jupiter are very low in the west and will set at 9:32, 9:34 and 9:51 p.m. respectively. Jupiter is above Mercury with Venus to the right or Mercury in the evening twilight. Mars, Saturn and the star Antares start the evening in the south-southwestern sky as a tightening triangle, moving to the southwest during the evening. Antares, whose name means Rival of Mars is below Saturn with brighter Mars to the right and closing in on Antares. In 6 days Mars will pass just above Antares with Saturn above all in a nearly straight line. Mars, moving rapidly to the east against the stars will set at 12:30 a.m. Saturn, is spectacular in telescopes, with its rings. It will set at 1:06 a.m.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Venus, Mercury and Jupiter at 9:18 p.m. (30 minutes after sunset), August 17, 2016. Created using Stellarium.
The planets, and Moon at 10 p.m., August 17, 2016. Created using Stellarium.
Saturn and some of its moons at 10 p.m. August 17, 2016. Created using Cartes du Ciel (Sky Charts).
The Moon as it might appear in binoculars tonight, August 17, 2016 at 10 p.m. Tonight the Moon is only a bit more than 7 hours from being full. Created using Cartes du Ciel (Sky Charts).
Planets at sunset and sunrise of a single night starting with sunset on the right on August 17, 2016. The night ends on the left with sunrise on August 18. 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.
08/11/2016 – Ephemeris – The Perseid meteors will peak tonight!
Ephemeris for Thursday, August 11th. The Sun rises at 6:41. It’ll be up for 14 hours and 12 minutes, setting at 8:53. The Moon, 1 day past first quarter, will set at 1:31 tomorrow morning.
This evening and tomorrow morning we should see the peak of the Perseid Meteor Shower. There is the expected broad peak of the shower which for us is after sunrise. However the meteoroid stream isn’t monolithic. Each pass of the comet in the inner solar system superimposes its debris on the general stream, so we will have increased activity all night tonight and even into Saturday morning. In general Perseid meteors will be seen to come from the northeast. The evening view will be hampered by the Moon which will drown out the dimmer meteors. The best time to view is after the Moon sets at 1:31 tomorrow morning until morning twilight becomes noticeable around 5 a.m. when over 100 meteors might be spotted an hour.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Perseid meteor shower radiant a about 2 a,m, during the period of the shower. Created using my LookingUp program.
Here are some meteors seen in the 2007 Perseid meteor shower taken by Scott Anttila. The image is centered on Cassiopeia. The radiant is low and a bit left of center in the image. The Double Cluster is seen below center and the Great Andromeda Galaxy is seen on the right just above center.
My best Perseid photo. From the 70’s.
08/10/2016 – Ephemeris – The planets tonight
Ephemeris for Wednesday, August 10th. The Sun rises at 6:39. It’ll be up for 14 hours and 15 minutes, setting at 8:55. The Moon, at first quarter today, will set at 12:55 tomorrow morning.
Today we turn from the small meteoroids that orbit the Sun that are producing the Perseid Meteor Shower to the larger members of the solar family, namely the bright planets. Venus and Mercury are very low in the west-northwest and will set at 9:44 and 9:50 p.m. respectively. Jupiter is in the west in the evening. It will set at 10:19 p.m. Mars, Saturn and the star Antares start the evening in the south-southwestern sky as a tightening triangle, moving to the southwest during the evening. Antares, whose name means Rival of Mars is below Saturn with brighter Mars to the right. The Red Planet is back in Scorpius. It will set at 12:46 a.m. Mars is moving rapidly to the east against the stars. Saturn is spectacular in telescopes, with its rings. Saturn will set at 1:34 a.m.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Venus, Mercury and Jupiter at 9:25 p.m. (30 minutes after sunset), August 10, 2016. Created using Stellarium.
The planets, Moon and constellations at 10 p.m., August 10, 2016. Created using Stellarium.
The Moon as it might appear in binoculars tonight, August 10, 2016 at 10 p.m. Created using Stellarium.
Saturn and its moons at 10 p.m. August 10, 2016. Created using Cartes du Ciel (Sky Charts).
Planets at sunset and sunrise of a single night starting with sunset on the right on August 10, 2016. The night ends on the left with sunrise on August 11. Actually all the naked eye planets are in the evening sky. Also shown is the Perseid meteor shower radiant. 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.
Also shown is the Perseid meteor shower radiant.
07/25/2016 – Ephemeris – Hermes’ Harp
Ephemeris for Monday, July 25th. The Sun rises at 6:21. It’ll be up for 14 hours and 54 minutes, setting at 9:16. The Moon, 1 day before last quarter, will rise at 12:34 tomorrow morning.
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 stars, 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. In binoculars, near Vega, two stars appear together. They barely appear to the unaided eye as one star, called Epsilon Lyrae.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Lyra as a tortoise shell harp. Created using Stellarium and free clip art.
Closeup on Vega and Epsilon Lyrae. Created using Stellarium.
07/12/2016 – Ephemeris – The Lanphier Observatory is open twice a week during the a summer
Ephemeris for Tuesday, July 12th. Today the Sun will be up for 15 hours and 18 minutes, setting at 9:27, and it will rise tomorrow at 6:10. The Moon, 1 day past first quarter, will set at 1:53 tomorrow morning.
There’s an observatory on the shores of Sleeping Bear Bay near Glen Arbor that is open to the public twice a week on clear nights. It’s the Leelanau School’s Lanphier Observatory, which is open Wednesday and Thursday evenings weather permitting from 10 p.m. to midnight until Labor Day. The Leelanau School is located at 1 Old Homestead Road, off M22. The Observatory is behind the Student Center and across the Crystal River. The observatory dome contains a 14 inch telescope on a computerized mount, and smaller telescopes may be available on the observatory deck. The observatory is run by Norm Wheeler, recently retired instructor. Get there early to enjoy the sunset on Lake Michigan.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Lanphier Observatory. From the Leelanau School website.
The dome interior with the 14 inch telescope and the computerized mount. From the Leelanau School website.
06/07/2016 – Ephemeris – The Moon reappears in the evening sky
Ephemeris for Tuesday, June 7th. Today the Sun will be up for 15 hours and 28 minutes, setting at 9:26, and it will rise tomorrow at 5:57. The Moon, 3 days past new, will set at 11:41 this evening.
The Moon tonight is a thin crescent with the night side faintly illuminated by the Earth. The effect is called earthshine. The small dark sea of Crises, or Mare Crisium, near the right edge of the moon will be cut in half by the moon’s terminator, its sunrise line. Venus, which passed behind the Sun yesterday, though now an official evening planet probably won’t become easily visible till near the end of summer. The evening sky now through mid July is a time where it seems that twilight never ends. However for almost the next two weeks, we have the bright planets Jupiter, Mars and Saturn plus the Moon to help us forget the seemingly forever twilight blues. After that we’ll have just the planets. Not a bad deal.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Moon showing earthshine at 10:30 p.m. June 7, 2016. Created using Virtual Moon Atlas.
Note: The image, from Virtual Moon Atlas, has been rotated to show the approximate appearance in the sky of the Moon low in the southwest. I didn’t attempt to add the sky brightness and color.
