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Ephemeris: 05/06/2024 – The star Arcturus: Not from around here
This is Ephemeris for Monday, May 6th. Today the Sun will be up for 14 hours and 29 minutes, setting at 8:54, and it will rise tomorrow at 6:23. The Moon, 1 day before new, will rise at 5:53 tomorrow morning.
Arcturus, a red giant star in the constellation of Boötes the herdsman, is about two thirds the way up the sky in the east-southeast at 10 pm. It’s one of the earliest stars to appear in twilight, being nearly tied in brightness with Vega, a white star low in the northeast. A pointer to Arcturus is the handle of the Big Dipper, following the arc of the handle to Arcturus. Though only 37 light years away, it’s not from around here. It’s passing through the galactic disk from north to south. Arcturus is about 7 billion years old, and is about 8% more massive than our Sun. It appears to be starting its red giant phase, after running out of hydrogen to fuse into helium in its core, and is beginning to fuse the helium. It’s 25 times the size of the Sun and 170 times brighter, and a preview of our Sun when it gets that old.
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
* Hertzsprung-Russell Diagram of a star’s surface (photosphere) temperature vs luminosity. The Main Sequence is where a star lives when it is burning hydrogen, and spends most of its life.
03/24/2014 – Ephemeris – The spring constellation of Leo the lion
Ephemeris for Monday, March 24th. The sun will rise at 7:38. It’ll be up for 12 hours and 21 minutes, setting at 7:59. The moon, 1 day past last quarter, will rise at 4:09 tomorrow morning.
Tonight about 10:00 the constellation of Leo the lion can be seen half way up the sky in the east-southeast. The head and mane of a male lion is seen as a backward question mark. This pattern of stars is also called the sickle. The bright star that is the dot at the bottom is Regulus, the “Little King Star”. To the lower left is a triangle of stars that is the lion’s hind end with the star Denebola at the far end. It is said that the reason the figure of a lion came to be seen in the stars here is because lions came from the desert, driven by the heat, to drink from the river Nile the time of the year that the sun was in this part of the sky. Leo is one of the constellations of the Zodiac. Leo can also be found by first locating the Big Dipper high in the northeast. Imagine a hole drilled in the bowl of the dipper and the water will fall on Leo’s back.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Leo and the Big Dipper (Ursa Major) using the angle measuring tool as an arrow. Date: March 24, 10 p.m. Created using Stellarium.
04/08/2013 – Ephemeris – The constellation Leo the lion
Ephemeris for Monday, April 8th. The sun will rise at 7:10. It’ll be up for 13 hours and 8 minutes, setting at 8:18. The moon, 2 days before new, will rise at 6:32 tomorrow morning.
Besides the advancing sunset times and warming temperatures, there’s another sign that spring is here. That’s the appearance of the constellation Leo the lion high in the southeast in the evening. The front of this beast is a backward question mark of stars with the bright star Regulus as the dot at the bottom. That’s his head, mane and chest. His haunches are a triangle of stars to the left, This year the planet Saturn is to the left of the Regulus. A way to find Leo is to remember that cat’s aren’t supposed to like water. Find the Big Dipper high in the northeast and imagine drilling a hole in the bottom of the bowl. The water will fall on Leo’s back. Also you’ll notice the stars of spring to the east are more sparse than those of winter to the west.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Leo and Ursa Major (Big Dipper) for 10 pm on April 8, 2013. Created using Stellarium.
09/27/2012 – Ephemeris – The Fisher in the stars
Ephemeris for Thursday, September 27th. The sun will rise at 7:36. It’ll be up for 11 hours and 53 minutes, setting at 7:29. The moon, 2 days before full, will set at 6:06 tomorrow morning.
The Big Dipper is swooping low in the northwestern sky in the evening now. The Big Dipper is not a constellation but part of the Great Bear for most peoples, and is enshrined by the International Astronomical Union as Ursa Major. To some of the Anishinabek peoples native to our region the stars of the Big Dipper belonged to a small weasel like animal call the Fisher. In a story I can’t relate here Fisher brought summer to the earth, and for his trouble was killed by an arrow to his only vulnerable spot, his tail. The Great Spirit would not let Fisher fall to earth, but placed him in the sky. His rising in the northeast signals the coming of spring, and when his bloody tail brushes the horizon in autumn his blood paints the maple trees red.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Fisher heads towards the northern horizon. Created using Stellarium and an unknown artist which I took liberties with.
The Fisher is also known as the Fisher Star (Ojiig’anung). I’ll have my version of the story posted soon.
The Fisher heads towards the northern horizon. Created using Stellarium and an unknown artist which I took liberties with.
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