Archive

Archive for the ‘Constellations’ Category

09/18/2020 – Ephemeris – A closer look at Cepheus the king’s most famous star

September 18, 2020 Comments off

This is Ephemeris for Friday, September 18th. Today the Sun will be up for 12 hours and 20 minutes, setting at 7:46, and it will rise tomorrow at 7:27. The Moon, 1 day past new, will set at 8:52 this evening.

There’s a faint constellation in the northeast above the W shaped constellation of Cassiopeia. It’s a nearly upside down church steeple of a constellation called Cepheus the king, and husband of queen Cassiopeia. Cepheus’ claim to astronomical fame is that one of its stars, Delta (δ) Cephei, is the archetype for the important Cepheid variable stars. Delta is the bottom most of a trio of stars at the right corner of the constellation. In the early 20th century Henrietta Leavitt discovered that Cepheids in the nearby galaxy the Large Magellanic Cloud varied in brightness with a period that was related to their average brightness. This meant that Cepheids could be used as standard candles to measure the great distances to other galaxies.

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

Addendum

Cassiopeia and Cepheus finder animation

Cassiopeia and Cepheus finder animation looking in the northeast at 9 pm or about an hour after sunset in mid-September. Created using Stellarium and GIMP.

Delta Cephei (circled) finder for mid-September at 9 pm or about an hour after sunset looking northeast. The brighter stars are marked by their Bayer Greek letters. Numerical designations are Flamsteed numbers. Created using Cartes du Ciel (Sky Chart).

Delta_Cephei_lightcurve

Light Curve of Delta Cephei. The pulsation period is 5.367 days. Credit: ThomasK Vbg – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=13887639

09/17/2020 – Ephemeris – Finding Cassiopeia the queen and Cepheus the king

September 17, 2020 Comments off

This is Ephemeris for Thursday, September 17th. Today the Sun will be up for 12 hours and 24 minutes, setting at 7:48, and it will rise tomorrow at 7:25. The Moon is new today, and won’t be visible.

The stars of the autumn skies are slowly replacing the summer stars from the east. Look midway up in the northeastern sky in the evening and you can find the W shaped constellation of Cassiopeia the queen. Cassiopeia is so far north that it never sets for us in Michigan. It is opposite the pole star Polaris from the handle of Big Dipper. There’s a dim star that appears above the middle star of the W which turns it into a very crooked backed chair, Cassiopeia’s throne. Above and left of Cassiopeia is a dim upside down church steeple shaped constellation of Cepheus the king, her husband. The Milky Way flows through Cassiopeia toward the northeastern horizon. She is a character in an autumn star story with five other constellations.

For my retelling of the Greek myth that links these autumn constellations click here.

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

Addendum

Cassiopeia and Cepheus finder animation

Cassiopeia and Cepheus finder animation looking in the northeast at 9 pm or about an hour after sunset in mid-September. Created using Stellarium and GIMP.

 

09/15/2020 – Ephemeris – The dolphin and the arrow, small summer constellations

September 15, 2020 Comments off

This is Bob Moler with Ephemeris for Tuesday, September 15th. Today the Sun will be up for 12 hours and 30 minutes, setting at 7:52, and it will rise tomorrow at 7:23. The Moon, 2 days before new, will rise at 6:01 tomorrow morning.

Located below the eastern edge of the Summer Triangle of three of the brightest stars in the sky, which is nearly overhead in our sky at 10 p.m., is the tiny constellation of Delphinus the dolphin. Delphinus’ 6 stars in a small parallelogram with a tail, really does look like a dolphin leaping out of the water. The parallelogram itself has the name Job’s Coffin. The origin of this asterism or informal constellation is unknown. Of the dolphin itself: the ancient Greeks appreciated this aquatic mammal as we do, and told stories of dolphins rescuing shipwrecked sailors. There’s another tiny constellation to the right of Delphinus, Sagitta the arrow a small thin group of 5 stars, which represents Cupid’s dart.

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

Addendum

Delphinus and Sagitta finder animation

Delphinus and Sagitta finder animation. Created using Stellarium and GIMP.

09/14/2020 – Ephemeris – Not exactly a mermaid

September 14, 2020 Comments off

This is Bob Moler with Ephemeris for Monday, September 14th. Today the Sun will be up for 12 hours and 33 minutes, setting at 7:54, and it will rise tomorrow at 7:22. The Moon, 3 days before new, will rise at 4:42 tomorrow morning.

Nearly 2000 years ago the southernmost of the constellations of the zodiac was Capricornus which is a water goat. That’s why the latitude on the Earth where the Sun is overhead on the winter solstice is called the Tropic of Capricorn. Not any more, Sagittarius, one constellation west past Jupiter and Saturn this year, has that honor today. Actually Capricornus does need the press. It’s large, but made up of dim stars. To me it looks like a 45 degree isosceles triangle, long side up, but which all the sides are sagging. The constellation is found low in the south-southeast at 10 p.m. The image that is supposed to be represented by the stars is that of a goat whose hind quarters are replaced by a fish’s tail, not a mermaid but a mergoat.

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

Addendum

Capricornus finder animation

Capricornus finder animation for September 14, 2020 at 10 pm for western Michigan. Note that the Teapot of Sagittarius is pouring its contents on the southwestern horizon is to the right. Created using Stellarium and GIMP.

Important seasonal latitudes on the Earth. Source: worldatlas.com

 

 

 

09/08/2020 – Ephemeris – The Anishinaabe folk saw a moose where we see Pegasus

September 8, 2020 Comments off

This is Ephemeris for Tuesday, September 8th. Today the Sun will be up for 12 hours and 51 minutes, setting at 8:05, and it will rise tomorrow at 7:15. The Moon, 2 days before last quarter, will rise at 11:14 this evening.

Yesterday I talked a bit about the constellation of Pegasus the flying horse ascendant in the east these September evenings. The Anishinaabe peoples of our area had no horses until after the Europeans arrived, but they did imagine a large four legged mammal here, the Mooz or Moose, spelled M-o-o-z and pronounced something like Moonz*. The Moose is upright, or will be when he is in the south. In the evening now he is in the east, his body is a large square of stars we call the Great Square of Pegasus standing on one corner. From the top star extend his neck and head. His great antlers cover the official constellation of Lacerta the lizard made of a zigzag of unremarkable faint stars. Unlike Pegasus the whole moose made it into the sky.

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

Addendum

Mooz finder animation

Mooz finder animation displaying both Western Pegasus and Lacerta constellations and Anishinaabe Mooz constellation for 10 pm in early September. Credit Stellarium (both star lore images are embedded in Stellarium). The Anishinaabe image is from Ojibwe Giizhig Anung Masinaaigan – Ojibiwe Sky Star Map created by A. Lee, W. Wilson, and C. Gawboy.

*Information on Mooz and its pronunciation can be found in the Ojibwe Peoples Dictionary at https://ojibwe.lib.umn.edu/main-entry/mooz-na. The language of the Ojibwe, Ojibwemowin is another name for Anishinaabemowin, the language of the Anishinaabe peoples.

09/07/2020 – Ephemeris – A first look at the autumn stars arriving: Cassiopeia and Pegasus

September 7, 2020 Comments off

This is Ephemeris for Labor Day, Monday, September 7th. Today the Sun will be up for 12 hours and 54 minutes, setting at 8:07, and it will rise tomorrow at 7:14. The Moon, 3 days before last quarter, will rise at 10:46 this evening.

In the evening as summer wanes and the Sagittarius teapot tips its contents on the southwestern horizon the constellations of autumn rise in the east. There’s the W shape of Cassiopeia in the northeast, which is so far north it never really leaves us in northern Michigan. Pegasus the flying horse of Greek mythology is perhaps the most famous of the autumn constellations, and easiest to find. Its body, a large square of four stars, is in the east, standing on one corner. It is known as the Great Square of Pegasus. Only the front half of the horse is in the sky, and he’s flying upside down with his neck and head extending to the right from the rightmost star. His galloping front legs extend upward from the top star.

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

Addendum

NE to SW Panorama

Northeast to southwest Panorama around the horizon at 10 pm tonight, September 7, 2020 showing the constellations discussed. Click on the image to enlarge. Created using Stellarium and GIMP.

 

09/03/2020 – Ephemeris – Why is the new NASA Moon landing program called Artemis?

September 3, 2020 Comments off

This is Ephemeris for Thursday, September 3rd. Today the Sun will be up for 13 hours and 6 minutes, setting at 8:14, and it will rise tomorrow at 7:09. The Moon, 1 day past full, will rise at 9:20 this evening.

Why is the new NASA crewed Moon landing program called Artemis? And why is it crewed, and not manned? Artemis was a Greek deity and Apollo’s twin sister. He was the god of the Sun and she was goddess, among other things, of the Moon. So she has a greater connection to the Moon than Apollo did. Spacecraft now-a-days are crewed, rather than manned to denote that both sexes are chosen to be astronauts in nearly equal numbers now. Of course that’s crewed spelled c-r-e-w-e-d, not c-r-u-d-e, though they sound the same. Deities of the Moon tend to be female be they Artemis, Cynthia, Luna, Selene, or Chang’e. Astronomers use Cynthia, Luna, and Selene (pronounced Sel-e-nae) in naming various aspects of the Moon and Chang’e is the goddess that the Chinese name their lunar landers after.

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

Addendum

NASA Artemis Logo

The logo chosen by NASA for the Artemis Program. The blue crescent at the bottom represents the earth. The gray ball at the top is the Moon. The curved red path is the stylized return path from the Moon to the Earth of the Orion capsule. Credit: NASA.

Artemis, goddess of the hunt and the Moon.

Artemis, goddess of the hunt and the Moon. Credit: Disney (Fantasia) source Daily Kos.

 

Categories: Mythology, NASA, The Moon Tags:

08/17/2020 – Ephemeris – The Milky Way’s Great Rift.

August 17, 2020 Comments off

This is Ephemeris for Monday, August 17th. Today the Sun will be up for 13 hours and 56 minutes, setting at 8:44, and it will rise tomorrow at 6:49. The Moon, 1 day before new, will rise at 5:53 tomorrow morning.

High overhead the Milky Way is seen passing through the Summer Triangle of three bright stars. Here we find the Milky Way splits into two sections. The split starts in the constellation of Cygnus the Swan or Northern Cross very high in the east. The western part of the Milky Way ends southwest of Aquila the eagle. This dark dividing feature is called the Great Rift. Despite the lack of stars seen there, it doesn’t mean that there are fewer stars there than in the brighter patches of the Milky Way. The rift is a great dark cloud that obscures the light of the stars behind it. Sometimes binoculars can be used to find the edges of the clouds of the rift, as stars numbers drop off suddenly. This is especially easily seen in Aquila.

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

Addendum

Great Rift in the Summer Triangle

The Great Rift finder animation as seen in the Summer Triangle, also showing the constellations of Cygnus the swan and the the northern part of Aquila the Eagle. This image a stack of 5 30 second exposures taken the morning of the Perseid meteor shower in a vain attempt to capture some meteors.

Actual Aquila

Annotated and animated photograph taken of Aquila August 13, 2018 during the Perseid meteor shower, the same night the image above. Taken by me and processed using Registax and GIMP.

08/13/2020 – Ephemeris – Sagittarius the archer, morphs into a teapot

August 13, 2020 Comments off

This is Bob Moler with Ephemeris for Thursday, August 13th. Today the Sun will be up for 14 hours and 7 minutes, setting at 8:50, and it will rise tomorrow at 6:44. The Moon, 2 days past last quarter, will rise at 1:53 tomorrow morning.

Due south and low in the sky at 10:30 p.m. now is one of my favorite asterisms the Teapot of the constellation Sagittarius. Sagittarius classically represents a centaur with a bow and arrow aimed at the heart of the constellation Scorpius to its west. I can find the bow and arrow here, but the half man half horse figure of the centaur eludes me. However the stout little teapot of the children’s song is quite obvious, with its base, lid on top, handle to the left and the spout to the right. To make things more realistic the bright Milky Way seems to rise like steam from its spout. As the night goes on the Teapot slides westward and appears to tilt, pouring its tea on the southwestern horizon. Jupiter and Saturn are just to the left of it now.

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

Addendum

Sagittarius-Teapot finder animation

Sagittarius-Teapot finder animation for 10 pm August 13, 2020. Click on the image to enlarge. Created using Stellarium and GIMP.

08/10/2020 – Ephemeris – The celestial eagle: Aquila

August 10, 2020 Comments off

This is Bob Moler with Ephemeris for Monday, August 10th. Today the Sun will be up for 14 hours and 15 minutes, setting at 8:55, and it will rise tomorrow at 6:41. The Moon, 1 day before last quarter, will rise at 12:20 tomorrow morning.

Aquila the eagle is a constellation that lies in the Milky Way. It’s in the southeastern sky as it gets dark. Its brightest star, Altair is one of the stars of the Summer Triangle, a group of three bright stars dominating the eastern sky in the evening now. Altair, in the head of the eagle, is flanked by two slightly dimmer stars, the shoulders of the eagle. The eagle is flying northeastward through the Milky Way. Its wings are seen in the wing tip stars. A curved group of stars to the lower right of Altair is its tail. Within Aquila the Milky Way shows many dark clouds as part of the Great Rift that splits it here. The other summer bird is Cygnus the swan above and left of Aquila, flying in the opposite direction.

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

Addendum

Aquila

Aquila the Eagle in the southeastern sky. Created using Stellarium.

Actual Aquila

Annotated and animated photograph taken of Aquila August 13, 2018 during the Perseid meteor shower. Alas, no Perseids in this photograph. Taken by me and processed using Registax and GIMP.

The constellations Lyra, Cygnus and Aquila

Deneb with the other stars and constellations in the Summer Triangle. Created using Stellarium.