Archive
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
06/03/2021 – Ephemeris – Arcturus in the Bible.
This is Ephemeris for Thursday, June 3rd. Today the Sun will be up for 15 hours and 23 minutes, setting at 9:23, and it will rise tomorrow at 5:58. The Moon, 1 day past last quarter, will rise at 3:30 tomorrow morning.
Arcturus is a bright orangish star that’s high in the south at 11 pm. It’s also found by following the arc of the handle of the Big Dipper, which is the ridiculous tail of Ursa Major the Great Bear. It was considered the “Guardian of the Bear”, It is in the base of the kite shaped constellation of Boötes, the herdsman or the Bear Chaser. The latter story I recounted earlier this year. The name from the Greek has been confused with the bear itself. Thus, in the King James version of the Bible Arcturus, not the Bear, meaning the Great Bear, is mentioned in the 38th chapter of Job. This has been corrected in the newer versions I’ve seen. Arcturus has a rich history in literature, mostly by being confused with the Great Bear.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Arcturus, Boötes and Ursa Major can be seen by looking overhead while facing the west-southwest at 11 pm in early June. Created using Stellarium. Lines and figures not included.
Biblical translations
King James Version of Job 38:31-32
31 Canst thou bind the sweet influences of Pleiades, or loose the bands of Orion? 32 Canst thou bring forth Mazzaroth in his season? or canst thou guide Arcturus with his sons?
New International Version of Job 38:31-32
31 “Can you bind the chains of the Pleiades? Can you loosen Orion’s belt? 32 Can you bring forth the constellations in their seasons or lead out the Bear with its cubs?
No one is sure what a Mazzaroth is.
05/10/2021 – Ephemeris – The story of the constellations Boötes and Ursa Major
This is Bob Moler with Ephemeris for Monday, May 10th. Today the Sun will be up for 14 hours and 38 minutes, setting at 8:58, and it will rise tomorrow at 6:18. The Moon, 1 day before new, will rise at 6:25 tomorrow morning.
Seen in the east 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 to the right. It is pointed to by the arc of the handle of the Big Dipper, higher in the east. Boötes represents a young hunter named Arcas, son of Callisto, a beautiful young lady who had the misfortune of being loved by Zeus the chief of the Greek gods. Zeus’ wife Hera, found out about it, and since she couldn’t punish Zeus, turned the poor woman into a bear. Arcas, many years later, unaware of the events surrounding his mother’s disappearance was about to kill the bear when Zeus intervened and placed them both in the sky to save her, as Arcas still pursues her across the sky nightly.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
03/11/2021 – Ephemeris – The Guardian of the Bear is rising
This is Ephemeris for Thursday, March 11th. Today the Sun will be up for 11 hours and 42 minutes, setting at 6:44, and it will rise tomorrow at 7:00. The Moon, 2 days before new, will rise at 7:09 tomorrow morning.
The brightest star of spring is Arcturus which will be visible by 9 pm low in the east-northeast. Arcturus can most famously be found by following the arc of the handle of the Big Dipper, which resides fairly high in the northeastern sky to it. “Follow the arc of the handle to Arcturus.” It’s the fourth or fifth brightest star in the sky, depending on the list. It was regarded as the “Guardian of the Bear”, meaning the Great Bear, Ursa Major, of which the Big Dipper is its hind end. Apparently it’s guarding its rear. Arcturus will stay in our evening sky until the end of summer and has a fascinating story of its own aside from its ancient mythology, which I’ll talk about when it’s higher in the sky. It’s located at the base of a kite shaped constellation called Boötes, which is now horizontal and too close to the horizon to be appreciated.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Arcturus rising finder animation for 9 pm tonight, March 11, 2021. Created using Stellarium and GIMP.
04/24/2020 – Ephemeris – The Big Dipper can be used to point to other stars and constellations
This is Bob Moler with Ephemeris for Arbor Day, Friday, April 24th. Today the Sun will be up for 13 hours and 57 minutes, setting at 8:39, and it will rise tomorrow at 6:41. The Moon, 2 days past new, will set at 10:21 this evening.
The Big Dipper can be used to point to other stars and constellations. Right now the Big Dipper is nearly overhead. The front bowl stars point to Polaris, the North Star which never seems to move in the sky. The handle can be used to find two stars. First follow the arc of the handle away from the bowl to find the fourth brightest night-time star Arcturus in the base of the kite shaped constellation of Boötes. Straighten the arc to a spike and continue to the south and you will come to the bright blue-white star Spica in Virgo the virgin. You can remember these stars with the phrase “Follow the arc of the handle to Arcturus and then spike to Spica” or if you prefer the alternate pronunciation of the latter star “Speak to Speeka”.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Finding stars and constellations using the Big Dipper. Click on the image to enlarge. Created using my LookingUp program for Windows.
04/13/2020 – Ephemeris – The story of Callisto and Arcas or Ursa Major and Boötes
This is Ephemeris for Monday, April 13th. Today the Sun will be up for 13 hours and 25 minutes, setting at 8:26, and it will rise tomorrow at 6:59. The Moon, 1 day before last quarter, will rise at 3:09 tomorrow morning.
Appearing mid way up the sky in the east at 10 p.m. is the kite shaped constellation of Boötes the herdsman. The bright star Arcturus is at the bottom-right of the kite, pointed to by the arc of the handle of the Big Dipper, above it. In one Greek myth Boötes represents a young hunter named Arcas, son of Callisto, a beautiful young lady who had the misfortune of being loved by Zeus the chief of the Greek gods. Zeus’ wife Hera, found out about the affair, and since she couldn’t punish Zeus, turned the poor woman into an ugly bear. Arcas, unaware of the events surrounding his mother’s disappearance in his youth was about to kill the bear when Zeus intervened and placed them both in the sky to save her. To this day Boötes continues to chase the Great Bear, Ursa Major, around the pole of the sky each night.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Bootes 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
05/23/2019 – Ephemeris – A look at the constellation of Corona Borealis
Ephemeris for Thursday, May 23rd. Today the Sun will be up for 15 hours and 5 minutes, setting at 9:12, and it will rise tomorrow at 6:06. The Moon, 3 days before last quarter, will rise at 1:37 tomorrow morning.
High in the east-southeast at 11 this evening can be seen a small nearly circular constellation of Corona Borealis, the Northern Crown. It is just below Boötes, the kite shaped constellation off the handle of the Big Dipper. According to Greek myth the crown was given by the gods to the princess Ariadne, daughter of King Minos of Crete. The crown is more like a tiara with the bright star Alphecca at the front. To the Anishinaabe people, who are natives of our region it is the Sweat Lodge. Part of what we call Hercules next to it is the Exhausted Bather, who is lying on the ground after the ceremony. The seven stones that are heated for the Sweat Lodge are the Pleiades, now too close to the Sun to be seen.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Animated Corona Borealis Finder Chart looking to the east-southeast at 11 p.m. May 23rd Click on the image to enlarge. Created using Stellarium and GIMP.
04/29/2019 – Ephemeris – Follow the arc to Arcturus
Ephemeris for Monday, April 29th. Today the Sun will be up for 14 hours and 8 minutes, setting at 8:45, and it will rise tomorrow at 6:34. The Moon, 3 days past last quarter, will rise at 5:06 tomorrow morning.
The Big Dipper, now nearing the zenith at 10 p.m. points to several stars and constellations. It’s handle points to two bright stars. First we follow the arc of the handle to the bright orange star Arcturus, the 4th brightest night-time star. The reason I say night-time is that the sun is a star also but by definition is not out at night. The arc to Arcturus is a how to find Arcturus and a clue to its name. Arcturus, midway up the sky in the east, lies at the base point of the kite shaped constellation of Boötes the herdsman. From Arcturus, straighten out the arc to a spike and one soon arrives at Spica a blue-white star in Virgo the virgin, now low in the southeast. Spica is also sometimes pronounced ‘Speeka’.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
How to find the stars Arcturus and Spica from the Big Dipper in late April. Created using my LookingUp program.
04/26/2019 – Ephemeris – The story of Ursa Major and Boötes
Ephemeris for Arbor Day, Friday, April 26th. Today the Sun will be up for 14 hours even, setting at 8:41, and it will rise tomorrow at 6:39. The Moon, at last quarter today, will rise at 3:39 tomorrow morning.
Seen in the east 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 to the right. It is pointed to by the arc of the handle of the Big Dipper, higher in the east. Boötes represents a young hunter named Arcas, son of Callisto, a beautiful young lady who had the misfortune of being loved by Zeus the chief of the Greek gods. Zeus’ wife Hera, found out about it, and since she couldn’t punish Zeus, turned the poor woman into a bear. Arcas, many years later, unaware of the events surrounding his mother’s disappearance was about to kill the bear when Zeus intervened and placed them both in the sky to save her, as Arcas still pursues her across the sky nightly.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Bootes 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
05/14/2018 – Ephemeris – Big Dipper: Pointer to the Stars
Ephemeris for Monday, May 14th. Today the Sun will be up for 14 hours and 47 minutes, setting at 9:03, and it will rise tomorrow at 6:14. The Moon, 1 day before new, will rise at 6:45 tomorrow morning.
The Big Dipper points to other stars and constellations. Right now the Big Dipper is nearly overhead. The front bowl stars point to Polaris, the North Star which never seems to move in the sky. The handle can be used to find two stars. First follow the arc of the handle away from the bowl to find the fourth brightest night-time star Arcturus in the base of the kite shaped constellation of Boötes. Straighten the arc to a spike and continue to the south and you will come to the bright blue-white star Spica in Virgo the virgin. You can remember these stars with the phrase “Follow the arc of the handle to Arcturus and then spike to Spica” or if you prefer the alternate pronunciation of the latter star “Speak to Speeka”.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
As can be seen below, there was one pointer function that didn’t make it into the program: A leaky dipper drips on Leo.
Using the Big Dipper as a pointer to other stars. The pointers to Polaris could be life saving, since it is always north. The view is southward. The cross displayed near the center is the zenith. One might want to lay down to take all this in. Created using my LookingUp program.
Bob Moler's Ephemeris Blog 