05/12/2023 – Ephemeris – Finding Virgo the virgin in the evening sky

This is Ephemeris for Friday, May 12th. Today the Sun will be up for 14 hours and 42 minutes, setting at 9:00, and it will rise tomorrow at 6:17. The Moon, at last quarter today, will rise at 3:44 tomorrow morning.

One of the large constellations we see in the south at 11 p.m. can be found using the Big Dipper overhead, follow the arc of the handle to the bright star Arcturus, then straighten the arc to a spike to reach Spica, a bright blue-white star in the south. Spica is the brightest star in the constellation Virgo, the virgin. She represents the goddess of the harvest, Virgo is holding a sheaf of wheat in depictions of her, and Spica is placed at the head of the sheaf. In the space between Spica and Leo the lion to her upper right is, a great cluster of thousands of galaxies just below naked eye visibility. The Virgo Cluster. Inside that cluster is galaxy M87, in whose center lies a black hole with the mass of 6.5 billion suns. The center of the cluster is at about 54 million light years away.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.

Addendum

Finding Virgo from the Big Dipper at 11 pm, May 12. There are no planetary interlopers this year. The small + sign marks the zenith, and the image faces south. Created using my LookingUp app, with captions added using LibreOffice Draw.

Virgo finder animation with Leo added as an aid for 11 p.m. tonight. Created using Stellarium and GIMP.

Markarian’s Chain, a small part of the Virgo Cluster of galaxies. Click or tap on the image to enlarge it. Credit: Daniel Dall’Olmo.

05/08/2023 – Ephemeris – How to find Leo the lion in the sky

This is Ephemeris for Monday, May 8th. Today the Sun will be up for 14 hours and 32 minutes, setting at 8:56, and it will rise tomorrow at 6:22. The Moon, 3 days past full, will rise at 12:57 tomorrow morning.

At 10 p.m. the spring constellation of Leo the lion will be high in the south. It can be found by locating the Big Dipper high overhead and imagining that a hole were drilled in the bottom of the bowl to let the water leak out. It would drip on the back of this giant cat. The Lion is standing or lying facing westward. His head and mane are seen in the stars as a backwards question mark. This group of stars is also called the sickle. The bright star Regulus is at the bottom, the dot at the bottom of the question mark. A triangle of stars, to the left of Regulus, is the lion’s haunches. Leo contains some nice galaxies visible in moderate sized telescopes. The stars in Leo’s part of the sky are fewer than those in the winter sky.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.

Addendum

Finding Leo the lion from the Big Dipper with no lines. The orientation is for 10 pm, May 8th. Can you find Leo? The Big Dipper? Created using Cartes du Ciel (Sky Charts).

Using the Big Dipper to find Leo. The orientation is for 10 pm on May 8th. For any other time, the orientation would be different, as would the position of the zenith (overhead point). Created using my LookingUp app.

Leo, with drawing of a lion. Created using Stellarium.

Note the star at the left end of Leo is named Denebola. There are several stars that start with “Deneb”. Deneb must mean tail in Arabic because most star names are Arabic in origin. Denebola is the tail of the lion. Deneb Kaitos is the tail of the autumn constellation of Cetus the whale, and Deneb itself is the tail of the summer constellation of Cygnus the swan.

02/13/2023 – Ephemeris – Follow the Drinking Gourd

This is Bob Moler with Ephemeris for Monday, February 13th. Today the Sun will be up for 10 hours and 21 minutes, setting at 6:08, and it will rise tomorrow at 7:44. The Moon, at last quarter today, will rise at 2:51 tomorrow morning.

In the decades before the Civil War, runaway slaves would travel, often at night, northward from the slave states in the south to the northern free states and Canada over the metaphorical Underground Railroad following the Drinking Gourd, the Big Dipper as their compass. For millennia, the North Pole of the sky had been passing near the handle of the Big Dipper or bear’s tail. As an amateur astronomer, who loves the dark, starlit skies, I’ve noticed that everyone is the same color in the dark! This year the Grand Traverse Astronomical Society will, once again, team with the Sleeping Bear Dunes for more Sun and star parties.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

“Follow the Drinking Gourd,” a show at the Virginia Living Museum’s Abbit Planetarium based on Jeanette Winter’s children’s book of the same name, tells the story of a slave family who used the stars to make their way north. Visitors can watch the free show Saturdays in February. (Courtesy of Virginia Living Museum) Via Daily Press, Newport News, VA.

07/08/2022 – Ephemeris – Polaris the North Star

This is Ephemeris for Friday, 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, 2 days past first quarter, will set at 2:17 tomorrow morning.

The bright star Polaris is a very important star. It is also known as the North Star and the Pole Star. Its unique position is nearly directly at the zenith at the Earth’s North Pole, making it a very important navigational star. It’s about 40 minutes of arc, or about one and a third Moon diameters away from the extension of the Earth’s axis into the sky. As a rule of thumb, its angular altitude above the northern horizon is approximately one’s latitude, and it stands about at the due north compass point. Polaris is found using the Big Dipper, using the two stars at the front of the dipper bowl to point to it. It’s located at the tip of the handle of the very dim Little Dipper which, this time of year in the evening, appears to be standing on its handle.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Polaris finder and location animation. Three frames: visual appearance in the sky, lines of the asterisms of the Big and Little Dippers, addition of the equatorial grid of celestial coordinates analogous to longitude and latitude on the Earth. The right ascension (like longitude) lines converge over the Earth’s North Pole, with Polaris close by. Created using Stellarium and GIMP.

The two stars at the front of the Big Dipper’s bowl, at the bottom of the dipper as it appears now in the evening, point to Polaris near the 11-hour right ascension line. Right ascension, though the same as earthly longitude, is measured in hours, rather than degrees. An hour equals 15 degrees, making 24 hours equal 360 degrees.

05/23/2022 – Ephemeris – the Moon and the morning planets plus the Big Dipper’s stars Mizar and Alcor

This is Bob Moler with Ephemeris for Monday, May 23rd. Today the Sun will be up for 15 hours and 6 minutes, setting at 9:13, and it will rise tomorrow at 6:05. The Moon, 1 day past last quarter, will rise at 3:44 tomorrow morning.

This week, the Moon is in the process of passing the morning planets. This morning it passed Saturn. Tomorrow afternoon and evening it will pass Mars, then Jupiter. By Thursday morning, the Moon will be below and left of Jupiter. Thursday evening, it will pass Venus.

Back to tonight’s sky, the Big Dipper is nearly overhead. In its handle is a star or two that are interesting. It’s the star at the bend in the handle. It’s called Mizar. Next to it, for those with good eyesight, is a dimmer star, called Alcor. The name Mizar is from the Arabic, meaning apron or cover, while Alcor means the forgotten one. Before optometrists, the ability to actually see both stars was a test for good eyesight, especially for Arabic warriors. The pair is also known as the “Horse and the Rider”.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

The Moon passing the morning planets at 5 am 5/23/2022 to 5/27/2022. Click on the image to enlarge it. Created using Stellarium and GIMP.

Mizar and Alcor in the Big Dipper as it is nearly overhead towards the north. Click on the image to enlarge it. Created using Stellarium.

Alcor seems to be a true companion to Mizar, since they are at the same distance of 81.7 light years. Alcor also has an unseen companion star. Mizar also has a much closer companion star that can be seen in a telescope. On top of that, each of them has another unseen companion star. Six stars for the price of two. What a deal.

How can you detect a companion star that can’t be seen? When analyzing a star’s spectra, the companion star betrays it presence by its chemical absorption lines shifting with respect to its primary due to the Doppler effect of its motion.

04/28/2022 – Ephemeris – The story of Arcas and Callisto

This is Bob Moler with Ephemeris for Thursday, April 28th. Today the Sun will be up for 14 hours and 6 minutes, setting at 8:44, and it will rise tomorrow at 6:35. The Moon, 2 days before new, will rise at 6:16 tomorrow morning.

Appearing in the eastern sky at 10 p.m. tonight is the kite shaped constellation of Boötes the herdsman. The bright star Arcturus is at the bottom of the kite which is horizontal to the left, pointed to by the arc of the handle of the Big Dipper, higher in the east. The Big Dipper is the hind end of the constellation Ursa Major, the Great Bear. In one story, Boötes represents a young hunter named Arcas, son of Callisto, a beautiful young woman who had the misfortune of being loved by god Zeus. Zeus’ wife, Hera, found out about the affair, and since she couldn’t punish Zeus, turned the poor woman into a bear. Arcas, many years later, unaware of why his mother disappeared, was about to kill the bear when Zeus intervened and placed them both in the sky, where he continues to chase her across the sky nightly.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Boötes and Ursa Major aka Arcas chasing Callisto around the pole of the sky. Created using Stellarium.

Arcas about to slay the bear by the 17th century artist Baur. Source: University of Virginia Electronic Text Center

03/28/2022 – Ephemeris – Finding the Great Bear

This is Ephemeris for Monday, March 28th. Today the Sun will be up for 12 hours and 34 minutes, setting at 8:05, and it will rise tomorrow at 7:29. The Moon, 3 days past last quarter, will rise at 6:47 tomorrow morning.

The Big Dipper is now reaching for the zenith in the northeast at 10 p.m. The seven bright stars are second to Orion in the west as the seven brightest stars in a constellation. If you looked up a list of constellations, you’d find that the Big Dipper isn’t there. Ursa Major or the Great Bear is the constellation of which the Big Dipper is a part. The seven bright stars of the dipper are the rump and long tail of this constellation. The rest of the bear, including his head and legs, are delineated by dimmer stars. An anatomical problem is its long tail, which was drawn in by the ancients of the old world. Their explanation was that a god had grabbed the bear’s stubby tail, whirled the bear around his head, and threw it into the sky, thus stretching its tail.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

The Great Bear (Ursa Major) finder animation. It shows the stars only, then the Big Dipper, Then the lines of the constellations Ursa Major and Ursa Minor (Lesser Bear and Little Dipper) as a bonus, and finally the constellation artwork. The orientation is for about 9:30 pm on the latter days of March. We are looking high in the northeast. In Northern Michigan, the bear’s front paw is near the zenith at that time. Created using Stellarium and GIMP.

03/21/2022 – Ephemeris – Finding the celestial lion

This is Ephemeris for Monday, March 21st. Today the Sun will be up for 12 hours and 12 minutes, setting at 7:56, and it will rise tomorrow at 7:42. The Moon, 3 days past full, will rise at 12:15 tomorrow morning.

At 10 p.m. the spring constellation of Leo the lion will be fairly high in the southeast. It can be found by locating the Big Dipper high in the northeast and imagining that a hole were drilled in the bowl to let the water leak out. It would drip on the back of this giant cat. The Lion is standing or lying facing westward. His head and mane are seen in the stars as a backwards question mark. This group of stars is also called the Sickle. The bright star Regulus is at the bottom, the dot at the bottom of the question mark. A triangle of stars, to the left of Regulus, is the lion’s haunches. Leo contains some nice galaxies visible in moderate sized telescopes. The stars in Leo’s part of the sky are fewer than those in the winter sky.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Leaky Big Dipper drips on Leo. The positions in the sky are for 10 pm local time, or about 2 hours after sunset. The little distorted cross at the top of the image marks the zenith. Look high in the east and southeast to see these stars. Created using my LookingUp program, GIMP and LibreOffice.

03/07/2022 – Ephemeris – The Fisher announces the beginning of the Maple sugaring season

This is Ephemeris for Monday, March 7th. Today the Sun will be up for 11 hours and 28 minutes, setting at 6:38, and it will rise tomorrow at 7:07. The Moon, 3 days before first quarter, will set at 12:19 tomorrow morning.

March is a month of transitions. The stars of the winter skies, that is Orion and his merry band of bright stars, move to the west as those of spring rise in the east. The Big Dipper is ascending in the northeastern sky, after lying low in the north during the long dark evenings in the heart of winter. The dipper is the hind end of the Great Bear, officially Ursa Major. The Anishinaabe peoples of the Great Lakes region saw the Big Dipper as the hind end and tail of a magical creature called Fisher, or in their language Ojiig, who brought summer to the Earth. Its position in the sky around the pole announces the seasons. The Fisher’s ascension high into the northeastern sky signals this month’s maple sugaring season.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). They may be different for your location.

Addendum

The Fisher announcing maple sugaring season – animation. Star positions for about 2 hours after sunset, near 45 degrees north latitude, for a week into March. Created using Stellarium and GIMP.

For the story of how the Fisher brought summer to the earth, and why he’s got an arrow sticking into his tail, click here.

10/08/2021 – Ephemeris – How the Fisher paints the trees their autumn colors

This is Bob Moler with Ephemeris for Friday, October 8th. Today the Sun will be up for 11 hours and 20 minutes, setting at 7:09, and it will rise tomorrow at 7:51. The Moon, 2 days past new, will set at 8:35 this evening.

The tree leaves are beginning to turn to reds and yellows as we advance into autumn. The native Anishinaabe peoples, whose homeland we share, have a story about how that came to be. Of how a magical weasel-like creature called the Fisher or, in their native language, Ojiig, brought summer to the Earth from Skyland. For his trouble, he was shot with an arrow in his only vulnerable spot, the tip of his tail. As he fell to Earth Gichi Manitou, the Great Spirit, caught him and placed him in the sky where we see the Great Bear and the Big Dipper. Every late autumn night we see his tail, the handle of the dipper, slowly swooping down to the horizon where his bloody tail paints the trees with their autumn colors.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT-4 hours). They may be different for your location.

Addendum

An animation of the Fisher brushing his tail along the horizon on autumn nights. Created using Stellarium and GIMP.

The Anishinaabe constellation drawings are from Ojibwe Sky Star Map Constellation Guide  by Annette S. Lee, William Wilson, Jeffrey Tibbets and Carl Gawboy available locally and online.  They are part of the latest editions of Stellarium, a free planetarium program.  Links to it are on the right.  Other information and links are available within the Stellarium.

Here’s one of the links: http://www.nativeskywatchers.com/.  It also contains links to Lakota star maps and lore.