01/10/2023 – Ephemeris – The constellation of Orion the hunter, unlucky in love

This is Bob Moler with Ephemeris for Tuesday, January 10th. Today the Sun will be up for 9 hours and 3 minutes, setting at 5:22, and it will rise tomorrow at 8:18. The Moon, halfway from full to last quarter, will rise at 9:01 this evening.

Before the Moon rises tonight, we will have two hours of darkness. Winter’s central constellation, Orion the hunter, doesn’t need the Moon to be absent to see its principal stars. He’s in the southeast before the Moon rises with red Betelgeuse in one shoulder and dimmer Bellatrix on the other, Saiph at one knee and bright blue-white Rigel at the other. Between his shoulders and knees runs his belt of three stars in a line. Above Betelgeuse, he is holding a club aloft and from Bellatrix he holds a lion skin shield to defend himself from the charge of Taurus the bull, above and right of him. I consider him a hard luck hero, with three different stories on how he died. Unlucky in love, he’s consigned to chase the Seven Sisters of the Pleiades throughout eternity.

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 finder animation with Mars. First, showing the unannotated sky looking southeast at Orion. Second, Orion with lines and labels of the stars at the corners of his body, and other bright stars in the view, plus the Pleiades and bright planet Mars, that’s just happening to be passing through this year. Third, the constellation art for Orion and Taurus the bull. Created using Stellarium, LibreOffice Draw and GIMP.

Here are the three stories of how Orion died: One: Orion raped the goddess Artemis, and so she killed him. Two: Orion was betrothed to Artemis, but her twin brother Apollo was jealous and caused her to kill him in a hunting “accident”. Three: Orion was killed by the sting of a scorpion, which is the reason Orion and Scorpius are never in the sky at the same time.

02/22/2022 – Ephemeris – The Winter Triangle

This is Ephemeris for Tuesday, February 22nd. Today the Sun will be up for 10 hours and 49 minutes, setting at 6:21, and it will rise tomorrow at 7:30. The Moon, 1 day before last quarter, will rise at 1:26 tomorrow morning.

I’ve talked about the Winter Circle of bright stars already this winter, but some other astronomers talk about the Winter Triangle. The stars involved are Betelgeuse in the hunter Orion, Sirius in Canis Major, Orion’s large hunting dog, and Procyon in Canis Minor, his other small hunting dog. These three stars enclose a rather blank piece of sky with the faint Milky Way running through it and the almost invisible constellation of Monoceros the unicorn. The Summer Triangle has three bright stars with no other close competition. The Winter Triangle has four other bright stars near it. Any three of these would make a nice triangle. One of these constellations, Canis Minor, is tiny with Procyon and one other star. It makes me think of a dachshund, or maybe, if I’m hungry, a hot dog.

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

The Winter Triangle. It encloses a pretty blank space where Monoceros the unicorn lies. Created using Stellarium with my annotations for the Winter Triangle.

01/31/2022 – Ephemeris – The winter circle of bright stars

This is Ephemeris for Monday, January 31st. Today the Sun will be up for 9 hours and 47 minutes, setting at 5:50, and it will rise tomorrow at 8:01. The Moon, 1 day before new, will rise at 8:48 tomorrow morning.

The winter skies are blessed with more first magnitude stars than any other season. Six of these stars lie in a large circle centered on the seventh, It’s called the Winter Circle. This circle is up in the evening. Starting high overhead is yellow Capella in Auriga the charioteer. Moving down clockwise is orange Aldebaran in the face of Taurus the Bull. Then down to Orion’s knee, we find blue-white Rigel. Down and left is the brightest star of all the brilliant white Sirius the Dog Star in Canis Major, lowest of these stars in the south-southeast. Moving up and left is white Procyon in Canis Minor, Above Procyon is Pollux in Gemini, the twins. All these are not quite centered on Betelgeuse, the bright red star in Orion’s shoulder.

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

The bright stars of winter arrayed in a not so accurate circle. Some call it the Winter Hexagon. These stars are what make the winter sky so brilliant on the rare clear night in winter. Created using Stellarium.

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.

02/11/2021 – Ephemeris – The Winter Triangle

This is Ephemeris for Thursday, February 11th. Today the Sun will be up for 10 hours and 17 minutes, setting at 6:06, and it will rise tomorrow at 7:47. The Moon is new today, and won’t be visible.

I usually talk about the Winter Circle of bright stars, but some other astronomers talk about the Winter Triangle. The stars involved are Betelgeuse in the hunter Orion, Sirius in Canis Major, Orion’s large hunting dog, and Procyon in Canis Minor, his other small hunting dog. These three stars enclose a rather blank piece of sky with the faint Milky Way running through it and the almost invisible constellation of Monoceros the unicorn. The Summer Triangle has three bright stars with no other close competition. The Winter Triangle has four other bright stars near it. Any three of these would make a nice triangle. One of these constellations Canis Minor is tiny, with Procyon and one other star. It makes me think of a dachshund, or maybe, if I’m hungry, a hot dog.

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

Addendum

Winter Triangle finder animation. It shows the star field, named first magnitude stars, then their constellations, then the Winter Triangle and constellations of the three stars. Click on the image to enlarge. Created using Stellarium and GIMP.

01/26/2021 – Ephemeris – A look at the bright red giant star Betelgeuse

This is Ephemeris for Tuesday, January 26th. Today the Sun will be up for 9 hours and 35 minutes, setting at 5:43, and it will rise tomorrow at 8:06. The Moon, 2 days before full, will set at 7:38 tomorrow morning.

At 8 pm the constellation of Orion the hunter is in the southeastern sky. The bright reddish star at the top left of Orion’s distinctive seven-star pattern is Betelgeuse a star near the end of its life. Being a single bright star, its distance is not well determined and is estimated to be about 550 light years away with an uncertainty of up to 20 percent, which make other estimates that uncertain too, like its mass and diameter. It’s somewhat less than 20 times the mass of the Sun, and a diameter possibly as large as Jupiter’s orbit of the Sun. It is old for a star of its mass, probably 8 million years old, with up to a million years to go on the outside before it will probably explode as a supernova and grace our skies as bright as the Moon for the better part of the better part of a year.

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

Addendum

The seven brightest stars of Orion in the south-southeast at 8 p. in late January.

“This artist’s impression shows the supergiant star Betelgeuse as it was revealed thanks to different state-of-the-art techniques on ESO’s Very Large Telescope, which allowed two independent teams of astronomers to obtain the sharpest ever views of the supergiant star Betelgeuse. They show that the star has a vast plume of gas almost as large as our Solar System and a gigantic bubble boiling on its surface. These discoveries provide important clues to help explain how these mammoths shed material at such a tremendous rate. The scale in units of the radius of Betelgeuse as well as a comparison with the Solar System is also provided.” Credit: ESO/L. Calçada (ESO is the European Southern Observatory)

12/28/2020 – Ephemeris – Some astronomical events of 2020

This is Ephemeris for Monday, December 28th. Today the Sun will be up for 8 hours and 50 minutes, setting at 5:09, and it will rise tomorrow at 8:19. The Moon, 1 day before full, will set at 8:01 tomorrow morning.

Let’s look at some astronomical and space news for this past year. A year ago the bright red star in the constellation Orion Betelgeuse underwent an unprecedented amount of dimming. It had pretty much recovered its brightness since. The best idea was that it ejected a cloud of dust that obscured part of the star from us. NASA’s Commercial Crew program came through this year with the successful launching of two crews to the International Space Station aboard the SpaceX Falcon 9 rocket and Crew Dragon Capsule. Boeing stood down this year after the failure of their uncrewed Starliner capsule to reach the space station last December. They will try another uncrewed attempt in a few months. I’ll have more tomorrow.

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

Addendum

Orion’s named stars including the belt stars. Betelgeuse is the bright red in the upper left. Created using Stellarium.

This comparison image shows the star Betelgeuse before and after its unprecedented dimming. The observations, taken with the SPHERE instrument on ESO’s Very Large Telescope in January and December 2019, show how much the star has faded and how its apparent shape has changed. Betelgeuse is one of the few stars close and large enough to be able to image its disk. Credit: ESO/M. Montargès et al.

Astronauts Shannon Walker, Victor Glover, and Mike Hopkins, and astronaut Soichi Noguchi inside the Crew Dragon capsule. Credit: SpaceX.

SpaceX Crew-1 Dragon capsule docking with the International Space Station. Credit: NASA

 

 

 

12/17/2020 – Ephemeris – Betelgeuse, Betelgeuse… Nope not saying it again

This is Bob Moler with Ephemeris for Thursday, December 17th. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:03, and it will rise tomorrow at 8:15. The Moon, 3 days past new, will set at 8:18 this evening.

The constellation Orion the hunter will have completely risen by 8 pm this evening. The leftmost bright red star in his shoulder is Betelgeuse. It’s phonetically spelled name (Beetle Juice) made the title of a movie in 1988. A year ago it’s dramatic dimming for a while caused some to wonder that it was about to explode in a supernova. Betelgeuse does normally vary a bit in brightness, but that was the most ever recorded. It’s a red giant star with a mass of 16 to 19 times the Sun’s. Its distance is thought to be about 550 light years away. It is difficult to measure the distance of single bright stars, even with satellites. Its age is maybe 8 to 8 ½ million years old out of a life expectancy of 10 million years, compared to the Sun’s 10 billion year life expectancy.

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

Addendum

Orion at 8 pm or about 3 hours after sunset in mid December. Its seven brightest stars make an unmistakable pattern with only Betelgeuse and Rigel labeled. Created using Stellarium.

This comparison image shows the star Betelgeuse before and after its unprecedented dimming. The observations, taken with the SPHERE instrument on ESO’s Very Large Telescope in January and December 2019, show how much the star has faded and how its apparent shape has changed. Credit: ESO/M. Montargès et al.

An image of the star Betelgeuse taken in infrared shows it’s surrounded by a vast cloud of dust that erupted from the surface (the bright star itself is masked out, though an image of it has been superposed there for scale — the star is about the size of the orbit of Jupiter, over a billion km wide). Credit: ESO/P. Kervella/M. Montargès et al., Acknowledgement: Eric Pantin via Phil Plait’s Bad Astronomy blog on syfy.com.

12/07/2020 – Ephemeris – Looking forward to the best of winter: Orion

This is Ephemeris for Monday, December 7th. Today the Sun will be up for 8 hours and 55 minutes, setting at 5:02, and it will rise tomorrow at 8:07. The Moon, at last quarter today, will rise at 12:25 tomorrow morning.

Orion, the central constellation of the winter evening sky will be completely risen by 9 this evening. Then it can be seen low in the east-southeast it’s upright rectangle of stars tilted to the left. The topmost star to the left in this rectangle is the famous red giant star Betelgeuse, which is reportedly dimming again. It’s in Orion’s shoulder. In his other shoulder is Bellatrix, a name known to Harry Potter fans. In his knees are Rigel, a blue-white giant star and Saiph. In the center of the rectangle are three stars in a straight line, now almost vertically arranged, Orion’s belt. And below his belt what seem to be three more stars, his sword. In the center of the sword stars can be found, with binoculars or telescope, Orion’s most famous feature, the Great Orion Nebula.

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

Addendum

Orion early December finder animation for 9 pm December 7th. Created using Stellarium and GIMP.

Orion’s named stars including the belt stars. Cursa, though named belongs to the neighboring constellation Eridanus the river. Created using Stellarium.

03/05/2020 – Ephemeris – Apparently Betelgeuse, though dimming wasn’t cooling as expected

Ephemeris for Thursday, March 5th. Today the Sun will be up for 11 hours and 24 minutes, setting at 6:36, and it will rise tomorrow at 7:10. The Moon, 3 days past first quarter, will set at 5:31 tomorrow morning.

Betelgeuse, the red star in the constellation Orion’s shoulder has apparently stopped dimming and has begun to brighten. The guesses as to the cause of the dimming are many. One suggested by a photograph taken of the star in December shows the southern half dimmed like it was covered by something. Betelgeuse out gasses lots of material, some of which condenses into dust. Could some of this dust mask the star and make it dimmer? I suspect that we’ll find out before too long. Many astronomers are wishing Betelgeuse would explode in a core collapse or type 2 supernova. At its approximate 700 light year distance we’d be safe, though a bazillion neutrinos would pass harmlessly through each one of us just before the light would get here.

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

Addendum

An image of the star Betelgeuse taken in infrared shows it’s surrounded by a vast cloud of dust that erupted from the surface (the bright star itself is masked out, though an image of it has been superposed there for scale — it’s about the size of the orbit of Jupiter, over a billion km wide). Credit: ESO/P. Kervella/M. Montargès et al., Acknowledgement: Eric Pantin via Phil Plait’s Bad Astronomy blog on syfy.com.

This comparison image shows the star Betelgeuse before and after its unprecedented dimming. The observations, taken with the SPHERE instrument on ESO’s Very Large Telescope in January and December 2019, show how much the star has faded and how its apparent shape has changed. Credit: ESO/M. Montargès et al.

More on this from Dr. Phil Plait’s Bad Astronomy blog on syfy.com: https://www.syfy.com/syfywire/mea-culpa-betelgeuse-and-its-dusty-convective-pulsations