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.

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.

01/12/2021 – Ephemeris – The celestial river Eridanus

This is Bob Moler with Ephemeris for Tuesday, January 12th. Today the Sun will be up for 9 hours and 7 minutes, setting at 5:25, and it will rise tomorrow at 8:17. The Moon, 1 day before new, will rise at 8:58 tomorrow morning.

One of the more obscure constellations around is Eridanus, which depicts a river. The river starts near the lower right corner of Orion, near the bright star Rigel and flows to the right then down near the southwestern horizon, then it meanders along the horizon to the south before turning below the horizon. One has to travel to the far south to see the southern terminus of the river, the bright star Achernar. Writers over the ages have seen here the Nile and the Earth circling river Ocean of the flat earth days. Achernar is actually two stars, the brightest was discovered to be the flattest star known, due to its rapid spin. The dimensions of Achernar A has been determined to be twice as wide across its equator than from pole to pole. It’s 139 light years away.

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

Addendum

An animation of the constellation Eridanus which is a river that flows from Rigel in Orion to the star Achernar below our southern horizon at latitude 45 degrees north. Create using Stellarium and GIMP.

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.

01/11/2019 – Ephemeris – The bright star in Orion’s knee: Rigel

Ephemeris for Friday, January 11th. The Sun will rise at 8:18. It’ll be up for 9 hours and 4 minutes, setting at 5:23. The Moon, 3 days before first quarter, will set at 10:55 this evening.

Yesterday I talked about the star Betelgeuse the bright red star in the top left of Orion’s upright rectangle. Orion is seen in the southeast at 9 in the evening. The blue-white star in Orion’s opposite corner is usually brighter. It is Rigel whose longer Arabic name of which Rigel is the first part means “Left Leg of the Giant”. Rigel is a giant itself, actually a super giant star, which is more a measure of its mass than its size, that of 23 solar masses. Its surface temperature is more than twice as hot as the sun. It is 120 thousand times as bright as the sun and 100 times its diameter. Its distance is around 860 light years. Those with telescopes might be able to spot a close companion star to Rigel, just at the edge of the bright arc light image of Rigel itself.

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

Addendum

Orion’s brightest stars with their names for 9 p.m. January 7, 2019. Click on the image to make Orion a giant hunter. Created using Stellarium..

Rigel with its companion star as photographed through a telescope. No attribution. Source: http://washedoutastronomy.com/content/urban-orion?page=1

01/08/2019 – Ephemeris – The river at Orion’s feet

Ephemeris for Tuesday, January 8th. The Sun will rise at 8:19. It’ll be up for 9 hours exactly, setting at 5:19. The Moon, 3 days past new, will set at 7:55 this evening.

One of the more obscure constellations around is Eridanus, which depicts a river. The river starts near the lower right corner of Orion, near the bright star Rigel and flows to the right then down near the southwestern horizon, then it meanders along the horizon to the south before turning below the horizon. One has to travel to the far south to see the southern terminus of the river, the bright star Achernar. Writers over the ages have seen here the Nile and the earth circling river Ocean of the flat earth days. Achernar is actually two stars, the brightest was discovered to be the flattest star, due to its rapid spin. The dimensions of Achernar A has been determined to be twice as wide across its equator than from pole to pole. It’s 139 light years away.

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

Addendum

An animation of the constellation Eridanus which is a river that flows from Rigel in Orion to the star Achernar below our southern horizon at latitude 45 degrees north. Create using Stellarium and GIMP.

01/07/2019 – Ephemeris – The stars of Orion

Ephemeris for Monday, January 7th. The Sun will rise at 8:19. It’ll be up for 8 hours and 59 minutes, setting at 5:18. The Moon, 2 days past new, will set at 6:57 this evening.

The seven bright stars of Orion now shine in the southeastern sky in the evening. Two shoulder stars, Betelgeuse, and Bellatrix, Two knee stars Saiph, and Rigel, In between are the three belt stars in a row, Alnitak, Alnilam, and Mintaka. Betelgeuse and Rigel are first magnitude stars, among the brightest in the sky, while the others are second magnitude. As far as brightness goes it puts the Big Dipper to shame with its six second magnitude and one third magnitude stars. Of course we in northern Michigan have the Big Dipper always, because it never sets. Orion, only about six months. Due to its position straddling the equator of the sky, Orion is seen by all the people of the world. Parts of him are even seen at the north and south poles.

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

Addendum

Orion’s brightest stars with their names for 9 p.m. January 7, 2019. Click on the image to make Orion a giant hunter. Created using Stellarium..

 

02/22/2018 – Ephemeris – The blue-white star at Orion’s knee

Ephemeris for Thursday, February 22nd. The Sun will rise at 7:32. It’ll be up for 10 hours and 49 minutes, setting at 6:21. The Moon, 1 day before first quarter, will set at 1:46 tomorrow morning.

The bright star at the bottom right corner of the big upright rectangle that is the giant hunter Orion’s body in the south-southeast is Rigel. It is a white star with a bluish tinge. It compares in brightness with Betelgeuse at the opposite end of Orion’s rectangle, though it’s usually a bit brighter. The mismatch in color makes brightness comparisons difficult. Rigel is about 860 light years away, It’s 23 times the mass of the Sun, 120 thousand the times brighter than the Sun, and a diameter almost the size of the orbit of Mercury. It’s age is thought to be about 8 million years. It has a visual companion star that can be seen in amateur telescopes. It’s not that dim, but suffers by being close to the arc light brightness of Rigel.

The 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. Created using Stellarium.

Rigel with its companion star as photographed through a telescope. No attribution. Source: http://washedoutastronomy.com/content/urban-orion?page=1

02/12/2018 – Ephemeris – The Winter Circle

Ephemeris for Monday, February 12th. The Sun will rise at 7:47. It’ll be up for 10 hours and 19 minutes, setting at 6:07. The Moon, 3 days before new, will rise at 6:29 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 at 9 p.m. 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 centered, well not quite, on Betelgeuse the bright red star in Orion’s shoulder.

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

Addendum

The bright stars of winter arrayed in a circle (well almost). Created using Stellarium.