02/09/2023 – Ephemeris – Orion’s Belt stars

This is Ephemeris for Thursday, February 9th. Today the Sun will be up for 10 hours and 10 minutes, setting at 6:02, and it will rise tomorrow at 7:50. The Moon, halfway from full to last quarter, will rise at 10:07 this evening.

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 according to the SIMBAD Astronomical Database. 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 Friday.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

Orion’s named stars, including the belt stars. Created using Stellarium.

01/05/2023 – Ephemeris – I’m Sirius about this being the brightest nighttime star!

Jan 5. This is Bob Moler with Ephemeris for Thursday, January 5th. Today the Sun will be up for 8 hours and 56 minutes, setting at 5:16, and it will rise tomorrow at 8:19. The Moon, 1 day before full, will set at 8:33 tomorrow morning.

The brightest nighttime star, Sirius, rises before 8 pm tonight. It can be found by following the constellation Orion’s three belt stars downward to near the east-southeastern horizon. As far as star-like objects go, Jupiter and Venus can always outshine Sirius. Mars can too, but only when it is near the Earth and this early evening when Mars is high in the sky and Sirius is low in the sky. When the Moon clears out of the evening sky, and Sirius rises higher, the other stars of its constellation will become visible. That constellation is Canis Major, Orion’s great hunting dog, from which it gets its nickname: Dog Star. The name Sirius means Dazzling One, an allusion to its great brightness and, being low in the sky, it twinkles mightily.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

A Sirius finder animation for January/early February at around 8 pm. Even in bright moonlight, the seven bright stars of Orion can be seen. The three stars of Orion’s belt make a great pointer to Sirius. Created using Stellarium, GIMP and LibreOffice (for the arrow).

01/06/2022 – Ephemeris – The named stars of Orion

This is Ephemeris for Thursday, January 6th. Today the Sun will be up for 8 hours and 58 minutes, setting at 5:18, and it will rise tomorrow at 8:19. The Moon, 3 days before first quarter, will set at 10:07 this evening.

Orion is still on an angle, leaning to the left, at 8 to 9 pm in the southeastern sky. It’s seven brightest stars have names from antiquity, and some of them are familiar. Starting from the top left, the bright reddish star is famous Betelgeuse. The top right star is Bellatrix, a name familiar to Harry Potter fans. The three stars of his belt, from bottom to top, are Alnilam, Alnitak, and Mintaka. The final bottom two stars from left to right are Saiph, pronounced “safe”. And blue-white Rigel, usually the brightest star of the constellation. These are the stars of Orion’s shoulders, belt and knees. He has other stars that delineate an arm with an upraised club and an arm holding a lion skin shield and a sword hanging from his belt.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). They may be different for your location.

Addendum

Orion’s named stars. Betelgeuse means “Armpit”. Bellatrix means “Female warrior”. The names of Orion’s belt stars refer to belt or girdle, Rigel refers to Orion’s foot. Saiph means sword, however Orion’s sword is the line of three stars below the belt stars. In binoculars, there’s more than three stars here. Around the second “star” of the sword is the Great Orion Nebula, barely visible here. Created using Stellarium.

04/09/2021 – Ephemeris – Follow the arc to Arcturus

This is Bob Moler with Ephemeris for Friday, April 9th. Today the Sun will be up for 13 hours and 12 minutes, setting at 8:20, and it will rise tomorrow at 7:06. The Moon, 2 days before new, will rise at 6:57 tomorrow morning.

The fourth or fifth brightest night-time star, depending on whose list you see, is now up in the east in the evening. It is Arcturus, a bright star with an orange hue. It can be found otherwise by finding the Big Dipper and tracing out and extending the curve of the handle and “Follow the arc of the handle to Arcturus”, to remember the name of the star and how to find it. Arcturus is about 37 light years from us and is moving quite rapidly across the sky, compared to most stars, though one would not notice it to the naked eye in one’s lifetime. Arcturus is slightly more massive than our Sun, and about 7 billion years old, and is entering its red giant stage of life after using all the hydrogen fuel in its core. Our Sun, being slightly less massive will survive on hydrogen a bit longer.

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

Addendum

How to find Arcturus. In the early spring Arcturus is low in the east in the evening. The Big Dipper is high in the northeast standing on its handle. To find and remember the name of this star simply follow the arc of the handle to Arcturus. Created using Stellarium and GIMP.

I’ll be talking more about Arcturus and the constellation it’s in Boötes the herdsman, a kite shaped constellation that’s currently laying on its side. He’s not herding, but chasing the Great Bear. But that’s another story.

01/11/2021 – Ephemeris – Procyon, the before the Dog Star

This is Bob Moler with Ephemeris for Monday, January 11th. Today the Sun will be up for 9 hours and 5 minutes, setting at 5:23 pm, and it will rise tomorrow at 8:17 am. The Moon, 2 days before new, will rise at 8:05 tomorrow morning.

Visible low in the east at 8 p.m. appears the star Procyon. To its right and below is Sirius the brightest night-time star. Procyon is the bright star in the constellation Canis Minor, or lesser dog. I can find only one other star in Canis Minor. Perhaps it’s a hot dog. If Sirius, in Canis major is the Dog Star then Procyon should be the Little Dog Star. However, Procyon is an interesting name. It means “Before the dog”, which is an allusion to the fact that Procyon, though east of Sirius actually rises before it. This is due to Procyon’s more northerly position. This effect doesn’t work south of the equator, however. Sirius will rise at about 7:30 tonight. Procyon is a star much like Sirius but is 32% farther away. It’s 11.4 to Sirius’ 8.6 light years away.

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

Addendum

Orion and his hunting dogs in early winter (8 pm, January 11, 2021) showing that Procyon does rise before Sirius.

01/05/2021 – Ephemeris – Orion’s named stars and their meanings

This is Ephemeris for Tuesday, January 5th. Today the Sun will be up for 8 hours and 57 minutes, setting at 5:17, and it will rise tomorrow at 8:19. The Moon, 1 day before last quarter, will rise at 12:42 tomorrow morning.

The constellation of Orion the hunter is visible in the southeast at 8 p.m. The names of the stars of Orion are interesting in themselves. Starting at the top left of the seven bright stars of Orion’s torso is Betelgeuse the bright red star, whose name means something like “Armpit of the Giant”. The star in Orion’s other shoulder is Bellatrix the “Amazon Star”. Below are the three stars of Orion’s belt, from left to right; Alnitak, Alnilam and Mintaka. Their names mean “Girdle”, “Belt of Pearls”, and “Belt” respectively. Down to Orion’s knees we look on the left to the star Saiph pronounced “Safe”* which means “Sword”, though it is a star in his knee. Finally, there’s the bright blue-white star Rigel whose name means “Left Leg of the Giant” in Orion’s other knee. These are the important stars that make up the figure of Orion in the sky. [BTW. most star names are Arabic, and what survives of them is just a part of the original Arabic phrases.]

* In the radio program I pronounced the word then spelled it out.

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

Addendum

The named stars of Orion. Created using Stellarium.

04/20/2020 – Ephemeris – The Little King Star

This is Ephemeris for Monday, April 20th. Today the Sun will be up for 13 hours and 45 minutes, setting at 8:34, and it will rise tomorrow at 6:47. The Moon, 2 days before new, will rise at 6:37 tomorrow morning.

The brightest star in the constellation Leo, which is high in the south these evenings is Regulus, whose name means “Little King”. It is appropriate due to its position in the heart of the king of beasts Leo the lion. Regulus is dead last in brightness of the 21 first magnitude stars, the brightest night-time stars. Even so, it is much brighter than the Sun. It is 79 light years away. The Sun would require a telescope to be spotted at that distance. Regulus appears to be a quadruple star system. The bright star itself is really two stars with a bright star orbited by a much dimmer star every 40 days. There are two dimmer stars much further out that share Regulus’ motion through space. There are an infinite variety of star system arrangements in the galaxy and beyond.

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

Addendum

The naked eye stars of Leo, including Regulus at 9:30 p.m. April 20, 2020. Note that Algieba is a binary star that can be seen in small telescopes. The yellow line that passes Regulus is the ecliptic the apparent path of the Sun. The Moon and planets also hang out near that line. Created using Cartes du Ciel (Sky Charts).

03/13/2020 – Ephemeris – Looking for Cancer the crab

Ephemeris for Friday, March 13th. Today the Sun will be up for 11 hours and 49 minutes, setting at 7:47, and it will rise tomorrow at 7:56. The Moon, 3 days before last quarter, will rise at 1:01 tomorrow morning.

Between the stars Castor and Pollux in Gemini high in the southeast and the star Regulus in Leo the Lion in the east-southeast lies the dimmest constellation of the zodiac, Cancer the crab. To me its 5 brightest stars make an upside down Y. There’s the stars in the center of the constellation Asellus Borealis and Asellus Australis, the north and south donkeys. There’s a fuzzy spot between and just west of them called Praesepe, the manger from which they are supposedly eating. In binoculars it resolves into a cluster of stars called the Beehive cluster. We amateur astronomers also know it as M44, the 44th object on 18th century comet hunter Charles Messier’s list of fuzzy objects that might be mistaken for comets.

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

Addendum

Cancer the crab finder chart. Note the beehive cluster, also known to amateur astronomers as M44, along with other catalog names. Prior to the invention of the telescope this cluster was known as Praesepe which means “Manger”. Click on the image to enlarge. Created using Stellarium and GIMP.

The constellation Cancer with star names and Praesepe. Asellus Borealis, the Northern Donkey; and Asellus Australis, the Southern Donkey are next to Praesepe the manger. Created using Stellarium.

We only hear about a manger at Christmas time.  It is simply a trough that horses, donkeys, and cattle eat from.

12/23/2019 – Ephemeris – Orion, rising even higher now

Ephemeris for Monday, December 23rd. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:05, and it will rise tomorrow at 8:18. The Moon, 3 days before new, will rise at 6:34 tomorrow morning.

The large and bright constellation of Orion the hunter is in the southeast at 9 p.m., with the bright star Sirius below it near the horizon. The equally spaced line of three stars of Orion’s belt are nearly vertical and point down to Sirius, also known as the Dog Star in Canis Major, Orion’s greater dog. Those three belt stars are in the center of an elongated rectangle of stars that tilt to the left. At the top left of Orion’s shoulder stars is the red giant star Betelgeuse. The right shoulder star is Bellatrix. Both Bellatrix and Sirius along with the names of other stars and constellations should be familiar to fans of the Harry Potter novels and movies, as members of the house of Black. The knee stars at the bottom of the rectangle are, from left to right Saiph and the brilliant blue giant star Rigel. Between his belt and knees are stars of his sword.

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

Addendum

The named bright stars of Orion and Canis Major, the dog rising below Orion with Sirius. Beside the stars mentioned in the program are the stars of Orion’s belt that have their own program later on in winter. Created using Stellarium.

In this season of Biblical stories it’s nice to note that Orion is mentioned four times in the Old Testament.  In Isaiah, Amos and twice in Job.  In Hebrew his name is “Kesîl”, meaning Fool.

12/19/2019 – Ephemeris – What does the bright star Procyon’s name mean?

Ephemeris for Thursday, December 19th. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:04, and it will rise tomorrow at 8:16. The Moon, at last quarter today, will rise at 1:42 tomorrow morning.

Visible low in the east at 8:30 p.m. will appear the star Procyon, sometimes called the little Dog Star. It’s in the constellation of Canis Minor, the little dog. It will rise at 8:05 p.m. for the Traverse City Interlochen area. Yet to rise at that time is the Dog Star itself, Sirius, the brightest night-time star. It won’t rise until 8:40 p.m., 35 minutes later even though Sirius is west of Procyon. I bring this up because the name Procyon means Before the Dog. At our latitude Procyon rises before any part of Canis Major, the big dog, Canis Major, that Sirius is in the heart of. This is sensitive to one’s latitude. At the equator, say in Ecuador. Sirius would rise first due to its westerly position by 54 minutes. You see Procyon is also north of Sirius and that makes all the difference.

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

Addendum

Stars and constellations in the east at 9 p.m., about 4 hours after sunset, on December 19th. This only works for locations above 30 degrees north latitude. Created using Stellarium.

Procyon and Sirius will for observers located at 30º 30′ north latitude.  South of that latitude Sirius will rise first.