Archive
08/27/2021 – Ephemeris – As Labor Day approaches, so do the autumn constellations
This is Bob Moler with Ephemeris for Friday, August 27th. Today the Sun will be up for 13 hours and 28 minutes, setting at 8:27, and it will rise tomorrow at 7:00. The Moon, 3 days before last quarter, will rise at 11:01 this evening.
Rising in the east at as it gets dark around 9:30 p.m. we can preview one of the great autumn constellations: Pegasus the flying horse of Greek myth. Its most visible feature is a large square of four stars, now standing on one corner. This feature, called the Great Square of Pegasus, represents the front part of the horse’s body. The horse is quite aerobatic because it is seen flying upside down. Remembering that fact, the neck and head is a bent line of stars extending from the right corner star of the square. Its front legs can be seen in a gallop extending to the upper right from the top star of the square. From the left star extend, not hind legs but the constellation of Andromeda, an important constellation in its own right. The Anishinaabe peoples native to this region saw a right side up Moose (Mooz) in the stars here.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hr). They may be different for your location.
Addendum
Pegasus image in the stars at 10 pm. Created using Stellarium. Drawing by Johan Meuris.
10/19/2020 – Ephemeris – This zodiacal constellation seems fishy
This is Bob Moler with Ephemeris for Monday, October 19th. Today the Sun will be up for 10 hours and 46 minutes, setting at 6:50, and it will rise tomorrow at 8:05. The Moon, 3 days past new, will set at 8:58 this evening.
High in the southeast at 9 p.m. are the four bright stars of the Great Square of Pegasus, the upside down flying horse. Lying along the left and bottom sides of the great square is the constellation of Pisces the fish, one of the 12 constellations of the Zodiac. Even though the constellation is called the fish, the fish themselves are not well represented in the stars. What can be traced in the stars is the rope, that’s tied to their tails, anchored at the extreme southeastern part of the constellation that is seen in the stars. It is near where the bright red planet Mars currently is. The right or western end of Pisces is the asterism, or informal constellation, of the Circlet. It’s the loop of 5 stars, the rope around the tail of one of the two fish.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Pisces finder animation showing the Great Square of Pegasus as a way to find it, though this year bright Mars will show where it is. Created using Stellarium and GIMP.
Mars’ apparent path for the rest of 2020 stays within Pisces. Mars doesn’t do a loop de loop as the ancients thought when they thought the Earth was motionless. It’s the effect of the Earth passing Mars in their orbits. Mars will stop its westward or retrograde motion around November 13th and resume its normal eastward motion. This view created using Cartes du Ciel (Sky Charts).
10/08/2020 – Ephemeris – A lady with a not so hidden jewel
This is Ephemeris for Thursday, October 8th. Today the Sun will be up for 11 hours and 19 minutes, setting at 7:09, and it will rise tomorrow at 7:51. The Moon, 1 day before last quarter, will rise at 11:09 this evening.
The stars of the constellations Andromeda the chained princess look like they’re supposed to be the hind legs of Pegasus the flying horse which is high in the southern sky above Mars at 9 p.m. Andromeda is high in the southeast She is seen in the sky as two diverging curved strings of stars that curve to the left and up from the upper leftmost star of the Great Square of Pegasus. Her predicament was caused by her boastful mother Cassiopeia, and the wrath of the god Poseidon. She was rescued by the hero Perseus, a nearby constellation, riding his steed Pegasus. Andromeda’s claim to astronomical fame is the large galaxy barely visible to the unaided eye just above the upper line of stars, the Great Andromeda Galaxy 2.5 million light years away.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Andromeda animated finder, including the Great Andromeda Galaxy. I’ve added Cassiopeia that some folks use to find the galaxy. I start with the leftmost star of the Great Square of Pegasus that connects to Andromeda. I count off two star on the lower curve because they are brighter than the upper curve. Then count two stars up. Next to that top star is a little smudge. That is the core of the Great Andromeda Galaxy. Created using Stellarium and GIMP.
The Great Andromeda Galaxy (M31) and two of its satellite galaxies M31 (left) and M110. Image taken by Scott Anttila.
09/08/2020 – Ephemeris – The Anishinaabe folk saw a moose where we see Pegasus
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 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
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
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.
10/24/2019 – Ephemeris – Let’s find Aquarius
Ephemeris for Thursday, October 24th. Today the Sun will be up for 10 hours and 33 minutes, setting at 6:43, and it will rise tomorrow at 8:11. The Moon, half way from last quarter to new, will rise at 4:41 tomorrow morning.
One of the constellations of the zodiac is in the southeastern sky at 8 in the evening. It’s the constellation of Aquarius the water bearer. The image that is supposed to be depicted in the stars is that of a fellow spilling a stone jar of water. Aquarius is fairly hard to spot because it is made of faint stars. One part of him, though, is easy to spot. That is the Water Jar, an asterism or informal constellation. It is a distinctive small nearly equilateral triangle of stars with another star in the center. Stars extending to the right from the water jar are the yoke he’s holding the water jar with. The Water jar is just below the top of the head of the upside down Pegasus the flying horse. The water is flowing down a vertical line of stars.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Aquarius finder animation for tonight at 8 p.m. October 24, 2019. Created using Stellarium and GIMP.
09/26/2019 – Ephemeris – Looking for Andromeda
Ephemeris for Thursday, September 26th. Today the Sun will be up for 11 hours and 58 minutes, setting at 7:33, and it will rise tomorrow at 7:35. The Moon, 2 days before new, will rise at 5:49 tomorrow morning.
In the east at 9 this evening can be found a large square of stars, the Great Square of Pegasus the flying horse. The square is standing on one corner. What look like its hind legs stretching to the left from the left corner star is another constellation, Andromeda the chained maiden. She is seen in the sky as two diverging curved strings of stars that curve upward. She was rescued by the hero Perseus, a nearby constellation, riding his steed Pegasus. Andromeda’s claim to astronomical fame is the large galaxy seen with the unaided eye just above the upper line of stars, the Great Andromeda Galaxy, about 2 and a half million light years away. To the unaided eye the galaxy appears as a small smudge of light. In binoculars the galaxy is a delicate spindle of light.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Pegasus & Andromeda animated finder chart for 9 p.m. in late September. Created using Stellarium and GIMP.
Andromeda at 9 p.m. with the Great Andromeda Galaxy. Created using Stellarium.
The Great Andromeda Galaxy (M31). Image taken by Scott Anttila.
09/19/2019 – Ephemeris – The celestial upside down flying horse
Ephemeris for Thursday, September 19th. 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, 2 days before last quarter, will rise at 10:42 this evening.
Rising and almost half way up the sky in the east at as it gets dark around 9 p.m. can be found one of the great autumn constellations: Pegasus the flying horse of Greek myth. Its most visible feature is a large square of four stars, now standing on one corner. This feature, called the Great Square of Pegasus, represents the front part of the horse’s body. The horse is quite aerobatic, because it is seen flying upside down. Remembering that fact, the neck and head is a bent line of stars emanating from the right corner star of the square. Its front legs can be seen in a gallop extending to the upper right from the top star of the square. From the left star extend, not hind legs but the constellation of Andromeda, rescued with the help of Pegasus.
For my retelling of the Greek myth that links these two and other autumn constellations click here.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Pegasus & Andromeda animated finder chart for 9 p.m. September 19, 2019. Click on the iamge to enlarge. Created using Stellarium and GIMP.
Ephemeris Extra – The Great Star Story of Autumn
The constellations of the great star story of autumn. Looking southeast on October 31 at 10 p.m. Created using Stellarium.
The great star wheel of the sky rolls on. In the evening sky gone are the stars of spring, and going are the southern stars of summer. In the morning sky before sunrise the stars of an early winter evening.
A constant in both skies are the stars of autumn: rising in the evening and setting in the morning. In no other part of the sky do so many constellations take part in a single story
The constellations, as seen above are Cepheus, Cassiopeia, Andromeda, Perseus, Pegasus, and Cetus. And their story goes like this:
In distant Ethiopia a crisis was brewing. King Cepheus and Queen Cassiopeia were at wits end as how to stop it. A giant sea monster named Cetus was ravaging the country’s coastal cities destroying them and devouring the inhabitants.
The king and queen consulted the temple oracle as to what happened and what could be done to save their country. The oracle intoned gravely that the fault was Cassiopeia’s. Suddenly the queen knew what happened. Cassiopeia was very beautiful and she had vainly boasted to all who could hear that she was more beautiful than even the sea nymphs, the lovely daughters of the sea god Poseidon.
The sea nymphs had heard of Cassiopeia’s boast and complained to their father. Poseidon, like any father, was angered, and being a god was able to do something about. Being a god means never having to say your sorry when you do something really mean. He loosed the monster Cetus upon the Ethiopians.
The oracle said that to appease the monster and Poseidon Cassiopeia would have to sacrifice her daughter the Princess Andromeda to the monster. That is how young Andromeda was chained to the rocks on the sea shore to await her doom…
Far away in ancient Greece a wedding was about to take place between the beautiful Princess Danaë and King Polydectes. Danaë’s son Perseus, fathered by Zeus, but that’s another story, wasn’t too happy about the proposed union, and Polydectes wanted the boy gone.
When Perseus asked Polydectes what he wanted for a wedding gift, he said, “I want the head of Medusa.” The boy immediately and foolhardedly agreed to get it for him.
Merdusa, it turns out, was one of three sisters, the Gorgons, who had snakes for hair. They were so ugly that one glimpse of them would turn the beholder to stone. Medusa was the only mortal one.
Luckily Perseus had the favor of the god Hermes and Athene. They armed him with Hermes’ winged sandals, a helmet that made him invisible, a pouch that would expand to hold an object of any size, a shiny mirror shield, and a sword.
Thus armed Perseus was told to find the Graiae or the gray women, who could tell him where the lair of the Gorgons was. They were three in number and shared but one eye and one tooth among them which they passed from one to another to use.
The Graiae refused to help Perseus. But he was able to force them to help by snatching their one eye while it was being passed from one to another. They told him that the Gorgons dwelt in the shore of the river Ocean at the edge of the world in perpetual twilight.
In approaching the lair of the Gorgons Perseus put on the helmet of invisibility. He approached Medusa stepping backwards, cautiously peering only at Medusa’s indistinct image in his shield. Perseus then swept his sword in a backhanded way and managed to sever Medusa’s head. It is said that Athene guided his hand.
Amazingly, springing full grown from Medusa’s blood was the winged white stallion Pegasus. After placing Medusa’s head in the pouch, Perseus mounted Pegasus for the trip home.
Cruising high in the sky over the Ethiopian coast Perseus spotted a horrific sight. There far below the beautiful Andromeda, in chains; her screams reaching his ears. Then he spotted why she was screaming. A short distance away, crawling out of the surf was the monster Cetus, heading towards Andromeda. Perseus immediately sizes up the situations and swooped with Pegasus down to a spot between Andromeda and the monster. Then, burying his head in his shoulder drew out the head of Medusa from the pouch and held it in front of Cetus. The head was as lethal in death as in life, and the monster was promptly turned to stone. Replacing the head in the pouch, Perseus freed Andromeda. They flew off to, well supposedly, live happily ever after.
Oh yes. Perseus did present the head of Medusa to his step father Polydectes. He, of course, was also turned to stone when he laid eyes on it.
There you have it a story connecting the autumn constellations of Cepheus, Cassiopeia, Andromeda, Perseus, Pegasus and Cetus.
Cepheus is a dim church steeple of a constellation. Its dim star Delta is a variable star, the prototype of an important class of distance measuring stars called Cephieds in its honor. Cassiopeia is the famous W shaped constellation that along with Cepheus doesn’t set at our latitude.
Perseus looks to me more like the cartoon roadrunner than a hero. As the ancients saw him, he is holding the head of Medusa, whose still glittering eye is the star Algol, a variable star which ghastly winks at us every 2 days and 21 hours.
Andromeda’s modern claim to fame is the great galaxy that lies beyond her stars, the Great Andromeda Galaxy which has the designation M31. The galaxy is faintly visible to the unaided eye on dark nights. The farthest you can see without optical aid. The galaxy lies some 2.5 million light years away.
Pegasus can be easily found by the square of stars the form his body. It’s called the Great Square of Pegasus.
What can be said about Cetus. It now represents a whale, not a monster. Its star Mira, which means “Wonderful”, slowly varies in brightness over 330 days from a star barely visible in binoculars to a 2nd or 3rd magnitude star.
Look up on an autumn evening and recapture the wonder the ancients had as they looked upward at the stars.
11/08/2018 – Ephemeris – More constellations of autumn: Andromeda, Triangulum and Aries
Ephemeris for Thursday, November 8th. The Sun will rise at 7:30. It’ll be up for 9 hours and 51 minutes, setting at 5:22. The Moon, 1 day past new, will set at 6:26 this evening.
High in the south at 9 p.m. can be seen the Great Square of Pegasus. From the top left star of the square diverge two curved lines of stars that is Andromeda the chained princess. Just below and left of Andromeda is a slender triangle of stars, none particularly bright. It has a name you can easily see in the stars, Triangulum, the triangle. Early Christians saw it as the Mitre of Saint Peter or the Trinity. Another small constellation seen below Triangulum is the much better known constellation Aries the ram, a small hockey stick of a constellation, not that hard to spot. It is the first constellation of the Zodiac, where the Sun is supposed to enter on the first day of spring. Due to the wobble of the Earth’s axis over the millenia, that honor is now given to Pisces.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Bob Moler's Ephemeris Blog 