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03/03/2022 – Ephemeris – Finding Cancer the crab
This is Ephemeris for Thursday, March 3rd. Today the Sun will be up for 11 hours and 16 minutes, setting at 6:33, and it will rise tomorrow at 7:15. The Moon, 1 day past new, will set at 7:46 this evening.
The constellation of Cancer the crab is made of dim stars, which are generally connected, in constellation charts, with lines that make either the letter K or an upside down Y, which lie directly between the star pair Castor and Pollux in Gemini and Regulus in Leo. In the center of the constellation is, what to the naked-eye is a fuzzy spot called Praesepe, or the manger. The two nearby stars, one to the northeast, and one to the southeast are Asellus Borealis, and Asellus Australis, the northern and southern donkey colts feeding out of the manger. Viewing that fuzzy spot with a pair of binoculars will reveal that it’s not fuzzy at all. It resolves into a cluster of stars, which astronomers, over the years, have called the Beehive cluster. Back in the first and second century CE, the Sun entered Cancer to begin the season of summer. It’s now just a transitional constellation between the winter and spring evening skies.
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
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 it. Created using Stellarium and GIMP.
A closer look at Cancer, noting the donkey stars Asellus Borealis and Australis feeding at the manger, Praesepe or M44, aka: the Beehive Cluster. Created using Cartes du Ciel (Sky Charts) and LibreOffice for captions. Adapted from a chart I created for the March 2022 issue of the GTAS newsletter, the Stellar Sentinel.
02/24/2022 – Ephemeris – The celestial unicorn
This is Ephemeris for Thursday, February 24th. Today the Sun will be up for 10 hours and 55 minutes, setting at 6:23, and it will rise tomorrow at 7:27. The Moon, 1 day past last quarter, will rise at 3:57 tomorrow morning.
Among all the constellations in the sky of animals real and mythical, there is also a unicorn. It’s called Monoceros, and inhabits the south-southeastern sky at 8 p.m. mostly bounded by Orion on the right, Canis Major, the great dog below and Canis Minor, the little dog to the left and above. Unfortunately for observers without a telescope, Monoceros, is devoid of any but the faintest stars. Maybe that’s why no one sees unicorns anymore. It has many faint stars because the Milky Way runs through it. To the telescopic observer and astrophotographer it is a feast of faint nebulae or clouds of gas and dust, the birthplace of stars, including the red rose of the Rosette Nebula* (NGC 2237), and Hagrid’s Dragon Cluster (NGC 2301), which sounds suspiciously like it was recently, and unofficially, named. Monoceros also contains a beautiful telescopic triple star system, Beta (β) Monocerotis.
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.
* The Rosette nebula surrounds the star cluster NGC 2244. This sparse star cluster is visible visually in telescopes. I’ve never been able to spot the nebula in a telescope, but it shows up, faintly, in my wide angle photographs of the area.
Addendum
Deep Sky Objects in and around Monoceros. Deep Sky Objects are telescopic objects that lie beyond the solar system. Click on the image to enlarge. Created using Stellarium.
Rosette Nebula in the infrared from the Spitzer Space Telescope. Credit: NASA/JPL/Caltech
The brighter stars of NGC 2301 (Hagrid’s Dragon Cluster, AKA Great Bird Cluster and Copeland’s Golden Worm). It’s also in two other catalogs: Cr 119 and Mel 54. Created using Stellarium and GIMP. The dragon image is from “Dragon Flying Cycle” on YouTube by Simon Hussey.
Telescopic Beta Monocerotis. William Hershel, discoverer of Uranus, said that it was “One of the most beautiful sights in the heavens.” Credit: F. Ringwald, Fresno State.
02/18/2022 – Ephemeris – Sirius, the brightest nighttime star
This is Ephemeris for Friday, February 18th. Today the Sun will be up for 10 hours and 37 minutes, setting at 6:15, and it will rise tomorrow at 7:36. The Moon, 2 days past full, will rise at 8:32 this evening.
In the evening, the great constellation of Orion the hunter can be seen in the south. Its large rectangle of bright stars is easily visible, even with a full moon. The three stars in a straight line, his belt, tilt downward to the left to a very bright star merrily twinkling lower in the sky. This star is called Sirius, also known as the Dog Star because it’s in the heart of Orion’s larger hunting dog, Canis Major. It is an arc light white star as seen in binoculars or telescope. It is the brightest star in the night sky, and a neighboring star, just twice the distance of the closest star to the Sun at 8.6 light years. It’s name, Sirius, has nothing to do with a dog, but is from the Greek meaning scorching for its brightness or sparkling, due to its intense twinkling.
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
In the southern sky, Orion’s belt points to Sirius. Created using Stellarium, Libreoffice and GIMP.
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.
01/28/2022 – Ephemeris – Auriga the charioteer without a chariot
This is Ephemeris for Friday, January 28th. Today the Sun will be up for 9 hours and 39 minutes, setting at 5:45, and it will rise tomorrow at 8:05. The Moon, 3 days past last quarter, will rise at 6:10 tomorrow morning.
The constellation Auriga the charioteer is nearly overhead at 9 p.m. It is a pentagon of stars, with the brilliant star Capella at one of its upper corners. Capella represents a she-goat he’s carrying. A narrow triangle of stars nearby Capella represents her three kids. The chariot, or by some a wagon is not seen in the stars and is supposed to be pulled by four horses, abreast. Or four oxen, or two oxen, a horse, and a zebra. None of these are depicted in the stars. The only constellation art I’ve seen is a man holding a large goat and three baby goats. There’s no chariot, no wagon and definitely no horses, oxen or zebras. What I see is a distinctive pentagon of stars, with one, Capella, brighter than the rest, and a nearby small triangle of stars.
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
Auriga and surrounding constellations at 9 pm in late January. Created using Stellarium.
Auriga star field, constellation lines and art. Auriga seems to be missing a kid, he’s supposed to have three, I think. Created using Stellarium and GIMP.
I checked other constellation art, and it appears that there are only two kids. I may have been wrong all these years. Yet the asterism of The Kids has three stars.
01/27/2022 – Ephemeris – Looking at the constellation of Gemini the twins
This is Ephemeris for Thursday, January 27th. Today the Sun will be up for 9 hours and 37 minutes, setting at 5:44, and it will rise tomorrow at 8:06. The Moon, 2 days past last quarter, will rise at 4:56 tomorrow morning.
Another famous winter constellation is Gemini. The constellation of Gemini the Twins is visible high in the southeast, above and left of Orion the hunter, at 9 p.m. The namesake stars of the two lads, are the two bright stars at the left end of Gemini, and are high and nearly in the east. Castor is on top, while Pollux is below. From them come two lines of stars that outline the two, extending horizontally toward Orion. In Greek mythology the lads were half brothers, Castor was fathered by a mere mortal, while Pollux was fathered by Zeus, but were born together as twins. When Castor was killed during the quest for the Golden Fleece, Pollux pleaded with Zeus to let him die also, so Zeus placed them together in the sky.
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
Gemini finder animation for 9 pm January 27th, showing just stars, constellation lines and star names, and figures of the lads. Click on the image to enlarge it. Created using Stellarium and GIMP.
01/24/2022 – Ephemeris – The Great Orion Nebula
This is Ephemeris for Monday, January 24th. Today the Sun will be up for 9 hours and 30 minutes, setting at 5:40, and it will rise tomorrow at 8:09. The Moon, 1 day before last quarter, will rise at 1:03 tomorrow morning.
The closest star nursery to us, places where stars are being born, is the Great Orion Nebula, 1,300 light years away. A light year is about 6 trillion miles, if you want to pace it out. It’s located in the constellation Orion’s sword that hangs below his belt. In as little as a pair of binoculars, it shines by emission and reflection of the light of a tiny clutch of four stars at its heart, which astronomers have called the Trapezium. These extremely hot young massive stars are not destined to live long. Unlike the Sun’s 10 billion year lifetime, these stars lifespans will be measured in millions of years. Yet do not mourn for them, even now stars are forming within their dusty cocoons in the nebula. The Trapezium stars’ deaths will provide heavy elements for new stars and planets.
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 lower part of Orion, with the Great Orion Nebula. Created using Stellarium.
The Great Orion Nebula (M42) long exposure photograph by Scott Anttila. Includes all the sword stars.
The inner and brightest part of the Great Orion Nebula. Also, visible are the four stars of the Trapezium, whose ultraviolet emissions light up the nebula. This is pretty much one’s perception of the nebula as seen in a small telescope, except it would appear colorless. In larger telescopes, one would perceive a greenish color. The red color of hydrogen is outside our night adapted visual range. The green emission is due to mainly doubly ionized oxygen and the green emission of hydrogen. Image by Scott Anttila.
01/21/22 – Ephemeris – A river in the sky, but not the Milky Way
This is Ephemeris for Friday, January 21st. Today the Sun will be up for 9 hours and 23 minutes, setting at 5:36, and it will rise tomorrow at 8:11. The Moon, halfway from full to last quarter, will rise at 9:31 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. And 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 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
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.
A model of Achernar by the European Southern Observatory (ESO).
01/20/2022 – Ephemeris – Taurus and the half sisters of the Pleiades
This is Bob Moler with Ephemeris for Thursday, January 20th. Today the Sun will be up for 9 hours and 21 minutes, setting at 5:34, and it will rise tomorrow at 8:12. The Moon, 3 days past full, will rise at 8:23 this evening.
High in the south-southeastern sky, and above-right of Orion, is the bright star Aldebaran. It’s at one tip of a letter V of fainter stars. The group of stars is the face of the constellation of Taurus the bull. Aldebaran is the angry bloodshot eye of the bull that’s charging Orion, whose defending himself with a lion skin shield and an upraised club. The stars in the V, and many more visible in binoculars, except for Aldebaran, belong to a star cluster called the Hyades. In Greek mythology, these are the half sisters of the Pleiades, visible as a tight group of stars above them. The V of stars is actually an upside down letter A, or Aleph, the first letter of the Hebrew and Mesopotamian alphabets. This was invented when Taurus, not Aries, was host to the Sun at the spring equinox.
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 Hyades (left) and the Pleiades (right) in this photograph I took January 4, 2016. Aldebaran is the bright star at the left tip of the Pleiades (right) of the Hyades.
Orion and Taurus finder animation for mid-January. 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.
Bob Moler's Ephemeris Blog 