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Ephemeris: 05/05/2026 – The constellation of Hydra the water snake slithers along the southern horizon
This is Bob Moler with Ephemeris for Cinco de Mayo, Tuesday, May 5th. Today the Sun will be up for 14 hours and 25 minutes, setting at 8:52, and it will rise tomorrow at 6:25. The Moon, halfway from full to last quarter, will rise at 1:15 tomorrow morning.
Low in the southwest to the southeastern sky in the evening one can spot the constellation of Hydra the water snake, the longest constellation of all. Unlike the monster of the same name, this Hydra has but one head, which is actually its most distinctive part. At 10 p.m. the head of Hydra is found below a line from brilliant Jupiter in the west and Leo the lion in the southwest. Hydra’s head is a small but distinctive group of 6 stars that make a drooping loop to the right. The rest of Hydra wends its way above the southern horizon below the bright blue star Spica in Virgo and Corvus the crow. Some delineations of Hydra have its tail tickling the constellation Libra, the balance, or scales, which has just risen in the southeast.
The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.
Addendum
The head of Hydra and the front part of Leo are parts of a constellation of the original inhabitants of our area, the Anishinaabek peoples. The constellation is the Great Underwater Panther, and the front part of the Leo is its curly tail. For more information about it check my blog post here.
Ephemeris: 04/13/2026 – How the Greeks saw the constellation Leo
This is Bob Moler with Ephemeris for Monday, April 13th. Today the Sun will be up for 13 hours and 23 minutes, setting at 8:25, and it will rise tomorrow at 7:00. The Moon, 3 days past last quarter, will rise at 5:35 tomorrow morning.
The constellations that we know are mostly those that come from the Sumerians and other civilizations who lived around what is now modern day Iraq. They were adopted and adapted by the ancient Greeks, and to us. Foremost of these was Leo the lion, seen high in the south-southeastern sky at 10 PM. It is easily found by imagining the bottom of the Big Dipper leaks. It will drip on the back of Leo, with its distinctive backward question mark as his front with his head and mane. To the Greeks he was the Nemean Lion, whose coat was impervious to arrows or spears. Heracles (Hercules) was able to kill it by first stunning it with a club then strangling it with his bare hands. It was the first of his Twelve Labors.
The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.
Addendum
Ephemeris: 04/10/2026 – The origin of the constellation Leo the lion.
This is Ephemeris for Friday, April 10th. Today the Sun will be up for 13 hours and 14 minutes, setting at 8:21, and it will rise tomorrow at 7:05. The Moon, at last quarter today, will rise at 4:29 tomorrow morning.
The constellation of Leo the lion was envisioned as far back as 4,000 BCE by the Sumerians. It was known as UR.GU.LA, the Great or Divine Lion. Back then it was in the same seasonal location where Gemini is today, the most northern of the constellations of the Zodiac, where the Sun was at the summer solstice. It was important for that reason. They showed him in their artwork as having wings, a sign of his divinity. The Sumerians gave Regulus, Leo’s brightest star, the name MUL.LUGAL, meaning the King Star, with MUL meaning or pertaining to “Star” and LUGAL meaning “King”. Regulus means the same thing. As empires and languages changed over the millennia, the star’s name always meant King.
The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.
Addendum
Leo as depicted by the Sumerians circa 4,000 BCE. Created with Stellarium using the Babylonian (Seleucid) Sky Culture.
Ephemeris: 04/09/2026 – Finding Leo the lion
This is Ephemeris for Thursday, April 9th. Today the Sun will be up for 13 hours and 11 minutes, setting at 8:20, and it will rise tomorrow at 7:07. The Moon, 1 day before last quarter, will rise at 3:58 tomorrow morning.
At 10 p.m. the spring constellation of Leo the lion will be high in the south-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 in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.
Addendum
Ephemeris: 03/12/2026 – Cancer the crab used to welcome summer
This is Ephemeris for Thursday, March 12th. Today the Sun will be up for 11 hours and 44 minutes, setting at 7:45, and it will rise tomorrow at 7:58. The Moon, 1 day past last quarter, will rise at 5:25 tomorrow morning.
There’s a line on some globes and maps at approximately 23 1/2° north latitude called the Tropic of Cancer. It’s related to the constellation Cancer the crab. However, Cancer no longer fits that role that it was named to a couple of thousand years ago, when the sun entered the constellation of Cancer on the first day of summer. That’s the latitude on the Earth where the Sun was directly overhead on the first day of summer. Now that an honor goes to Gemini. The way we draw the figure of that constellation, the Sun is right near Castor’s big toe on the first day of summer. But I don’t think they’re going to change the name anytime soon. The reason for the change is that the Earth’s axis slowly wobbles like a top or gyroscope as they slow down. The effect is called precession.
The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.
Addendum
The Greek letter epsilon in the image above represents the tilt of the Earth’s axis of around 23.5°. Astronomers call it the obliquity of the ecliptic, the angle between the ecliptic and the celestial equator as seen in the illustration below.
Ephemeris: 03/10/2026 – Finding Cancer the crab
This is Ephemeris for Tuesday, March 10th. Today the Sun will be up for 11 hours and 38 minutes, setting at 7:42, and it will rise tomorrow at 8:02. The Moon, 1 day before last quarter, will rise at 3:50 tomorrow morning.
The constellation of Cancer the crab is made of dim stars, which are generally connected, in constellation charts, with lines that make either the letter K or an upside down Y. It lies directly between the star pair Castor and Pollux in Gemini and Regulus in Leo. In the center of the constellation is, what to the naked-eye is a fuzzy spot called Praesepe, or the manger. The two nearby stars, one above left, and one below left are Asellus Borealis, and Asellus Australis, the northern and southern donkey colts feeding out of the manger. Viewing that fuzzy spot with a pair of binoculars will reveal that it’s not fuzzy at all. It resolves into a cluster of stars, which astronomers, over the years, have called the Beehive cluster.
The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.
Addendum
Ephemeris: 02/20/2026 – The star that’s called “Before the Dog”
This is Ephemeris for Friday, February 20th. Today the Sun will be up for 10 hours and 43 minutes, setting at 6:18, and it will rise tomorrow at 7:33. The Moon, 3 days past new, will set at 10:21 this evening.
The star Procyon is in Orion’s little hunting dog, Canis Minor, which contains only one other star. It can be found by using the shoulder stars of Orion, Bellatrix and Betelgeuse, pointing to the left and down a bit to Procyon at 9 PM. With Jupiter above, Betelgeuse to the right and Sirius below, it makes an imposing diamond of stars. The word Procyon means “Before the Dog” meaning that rises before the Dog Star, Sirius, even though it is east of it. Procyon is also north of Sirius, which for observers above 30° north latitude, it does indeed rise before the Dog Star. It is a star like Sirius, though it’s not as bright, or white. Procyon is 11.5 light years away while Sirius is 8.6. Both have tiny white dwarf companion stars.
The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.
Addendum
Ephemeris: 02/16/2026 – The Dog Star
This is Bob Moler with Ephemeris for President’s Day, Monday, February 16th. Today the Sun will be up for 10 hours and 31 minutes, setting at 6:12, and it will rise tomorrow at 7:39. The Moon, 1 day before new, will rise at 7:51 tomorrow morning.
The second-brightest star-like object in the evening sky is Sirius, also known as the Dog Star. It also is the brightest nighttime star in our skies period. Tonight at 9 p.m. it’s located in the southern sky. The Dog Star name comes from its position at the heart of the constellation Canis Major, the great dog of Orion the hunter. The three stars of Orion’s belt tilt to the lower left to Sirius. Sirius means ‘Dazzling One’, because of its great brilliance and twinkling. Its Egyptian name was Sopdet, and its first appearance in the dawn skies around July 20th signaled the flooding of the Nile, and the beginning of the agricultural year. The relationship of the heliacal rising of Sirius and the seasonal or tropical year lasted from about 2900 BCE to the start of the Common Era. Sirius owes much of its brilliance to the fact that it lies close to us, only 8.6 light years away.
The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.
Addendum
Trivia Note
The Greeks invented the term “Dog days of summer” for the hottest days of July because they thought that Sirius added its intensity to the heat of the Sun to make it hotter out. So why doesn’t Sirius help warm our winter nights? Just asking.
Ephemeris: 02/09/2026 – Orion’s amazing belt stars
This is Ephemeris for Monday, February 9th. Today the Sun will be up for 10 hours and 11 minutes, setting at 6:02, and it will rise tomorrow at 7:50. The Moon, at last quarter today, will rise at 3:01 tomorrow morning.
Orion’s belt of three stars is one of the most noticeable star groupings in the sky. There are no other groups of three bright stars in a straight line visible anywhere else in the sky. The star’s names from left to right are Alnitak, Alnilam and Mintaka. They are actually a bit farther away than the other bright stars of Orion. Alnilam, the center star, is over three times the distance of red giant Betelgeuse above them and over twice as far as blue white giant star Rigel below them. Alnilam is 375 thousand times brighter than the Sun. These three stars were also known as Frigga’s Spindle by the Norsemen. Frigga, also known as Freya, is the goddess from which we get the name of the day of the week we call Friday.
The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.
Addendum
Ephemeris: 02/05/2026 – The celestial unicorn
Feb 5. This is Ephemeris for Thursday, February 5th. Today the Sun will be up for 10 hours even, setting at 5:57, and it will rise tomorrow at 7:55. The Moon, halfway from full to last quarter, will rise at 10:34 this evening.
Among all the constellations in the sky of animals real and mythical, there is also a unicorn. It’s called Monoceros, and inhabits the southeastern sky at 8 p.m. mostly bounded by Orion on the right, Canis Major, the great dog below and Canis Minor, the little dog to the left and above. Unfortunately for observers without a telescope Monoceros, is devoid of any but the faintest stars. Maybe that’s why no one sees unicorns anymore. Though it lacks bright stars Monoceros is full of wonders revealed by telescopes and photography. A feast of faint nebulae or clouds of gas and dust, the birthplace of stars, including the red rose of the Rosette Nebula, and the more recently named Hagrid’s Dragon Cluster (NGC 2301).
The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.
Addendum
Bob Moler's Ephemeris Blog 