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02/16/2017 – Ephemeris – The Winter Circle
Ephemeris for Thursday, February 16th. The Sun will rise at 7:40. It’ll be up for 10 hours and 32 minutes, setting at 6:12. The Moon, 2 days before last quarter, will rise at 12:17 tomorrow morning.
The winter skies are blessed with more first magnitude stars than any other season. These are the twenty-one brightest stars in the sky. Six of these stars lie in a large circle centered on the seventh. This circle is up all evening now that we are in the heart of winter. Starting high overhead is Capella in Auriga the charioteer. Moving clockwise, we come to Aldebaran in the face of Taurus the Bull. Then down to Orion’s knee we find Rigel. Down and left is the brightest star of all Sirius the Dog Star in Canis Major Orion’s large hunting dog, lowest of these stars in the south. Moving up and left there is Procyon in Canis Minor, Then above it is Pollux in Gemini the twins. All are centered on Betelgeuse in Orion.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Winter Circle of 1st magnitude stars. Created using my LookingUp program.
01/26/2017 – Ephemeris – Is it a dachshund or a hot dog?
Ephemeris for Thursday, January 26th. The Sun will rise at 8:07. It’ll be up for 9 hours and 36 minutes, setting at 5:43. The Moon, 1 day before new, will rise at 7:40 tomorrow morning.
The constellation Orion has two hunting dogs. We’ve seen Canis Major the greater dog at Orion’s feet with Sirius in its heart. The lesser dog, Canis Minor is level with Betelgeuse in Orion’s shoulder and off to the left. Just two stars mark it. Is it a dachshund or is it a hot dog? You decide. It’s brighter star’s name is Procyon which means “Before the dog”, an odd title. It means that though east of Sirius, it rises before Sirius, due to its more northerly position in the sky. In many ways Procyon is nearly a twin of Sirius. It shines with the same white color, although a bit cooler, and has a white dwarf companion like Sirius. It’s a bit farther away than Sirius’ 8 light years. Procyon is 11 and a half light years away. Procyon, Betelgeuse and Sirius make the winter triangle.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Procyon and Orion’s hunting dogs animation also showing the Winter Triangle asterism*. Created using Stellarium and GIMP.
* Asterism – an informal constellation like the Big Dipper, the Northern Cross, or the Summer Triangle. Not one of the 88 official constellations.
01/09/2017 – Ephemeris – Betelgeuse the bright red star in Orion
Ephemeris for Monday, January 9th. The Sun will rise at 8:18. It’ll be up for 9 hours and 3 minutes, setting at 5:21. The Moon, 3 days before full, will set at 6:06 tomorrow morning.
The bright red star in constellation Orion’s shoulder is Betelgeuse, 643 light years away give or take 146 light years. Betelgeuse is a shortened form of an Arabic phrase that means “Armpit of the central one”. Orion is seen in the south in the evening. Even at its great distance it’s the star whose surface is easiest seen, after the sun of course. That’s because it’s so big. Possibly larger around than the orbit of Jupiter, though that’s hard to determine. Recent telescopic observations of Betelgeuse have shown shells of gas surrounding the star. A star like Betelgeuse is so bloated that it can be described as a red-hot vacuum, thus its edge or limb is much darker than its center. The sun has limb darkening too, but it is much less noticeable.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Orion upright and due south. Created using Stellarium.
Betelgeuse and its nebula. From European Southern Observatory’s Very Large Telescope.
Betelgeuse is a single star like the Sun there is evidence that Betelgeuse may have eaten its companion star 100,000 years ago, yum! http://phys.org/news/2016-12-famous-red-star-betelgeuse-faster.html
12/27/2016 – Ephemeris – The stars of Orion
Ephemeris for Tuesday, December 27th. The Sun will rise at 8:19. It’ll be up for 8 hours and 49 minutes, setting at 5:09. The Moon, 2 days before new, will rise at 7:26 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. The whole of its constellation stars aren’t up at 9 p.m., but they will all clear the horizon by 10 p.m. Those three belt stars are in the center of an elongated rectangle of stars 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.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Orion, star names, and constellation art animation position for 9 p.m. December 27. Created using Stellarium and GIMP. Artist: Johan Meuris.
In the image above I’ve added the belt star names, though they are generally covered in a program of their own.
12/26/2016 – Ephemeris – Orion takes its place as the central winter constellation
Ephemeris for Monday, December 26th. The Sun will rise at 8:19. It’ll be up for 8 hours and 49 minutes, setting at 5:08. The Moon, 3 days before new, will rise at 6:33 tomorrow morning.
The great constellation of Orion the hunter has claimed his rightful position as the central winter constellation. It’s the most famous constellation of all. Think the Big Dipper is a big deal? They can’t even see it from the large population centers of Australia. Parts of Orion can be seen from every part of the Earth from pole to pole. Orion’s distinctive feature is his belt of three bright stars in a row. This tilted belt is in the center of a large rectangle of bright stars. The upper left star is Betelgeuse a red giant star. The lower right star is Rigel a blue giant star. Orion was an unlucky fellow of Greek myth. One wonders why he gets this splashy constellation in Winter while Hercules gets a dim upside down constellation in the spring sky.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Orion and the head of Taurus photograph by myself January 4, 2016 at 11:30 p.m. It’s a stack of unguided 20 second exposures.
Orion from mid latitudes north of the equator. Orion would be upside down if viewed south of the equator. Created using Stellarium.
The Ephemeris radio programs are very short (59 seconds) so I will visit Orion several times during the winter to explore its mythology and deep sky wonders within, or search past posts for Orion.
01/18/2015 – Ephemeris – Betelgeuse, a dying star
Ephemeris for Martin Luther King Day, Monday, January 18th. The Sun will rise at 8:15. It’ll be up for 9 hours and 16 minutes, setting at 5:31. The Moon, 2 days past first quarter, will set at 3:47 tomorrow morning.
Now that the Moon is getting brighter and making the fainter tars in the constellations harder to find, let’s look at the bright stars of Winter. Today, let’s look at Betelgeuse the reddish star in Orion the hunter’s shoulder. Lets get the basic facts out first. Betelgeuse is a red giant star 90 thousand to 150 thousand times brighter than the Sun and 7 to 20 times the Sun’s mass. It’s around a thousand times the diameter of the Sun, making it about the diameter of the orbit of Jupiter. It’s about 650 light years away, but that’s a bit uncertain. It is shedding gasses at a prestigious rate. Though only 7 million years old, it may explode as a supernova in the next million years. And yes, we’re far enough away.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Some of Orion’s named stars, including Betelgeuse. Orion at 8 p.m. Created using Stellarium.
Betelgeuse and its nebula. From ESO’s Very Large Telescope.
01/07/2016 – Ephemeris – The Orion entourage
Ephemeris for Thursday, 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 before new, will rise at 6:42 tomorrow morning.
The whole Orion entourage is now visible in the southeast at 9 p.m. Orion the hunter with stars at his shoulders and knees and has a belt of three stars in a straight line. He has one arm upraised holding a club from the reddish star Betelgeuse and in the other arm he’s holding a lion skin shield fending off an attack from Taurus the bull above and right of him. Following the belt stars to the lower left we come to the brightest night-time star Sirius the Dog Star in the heart of Canis Major, his great hunting dog. Making a nearly equilateral triangle with Sirius and Betelgeuse is Procyon the little dog star in Canis Minor, Orion’s other small hunting dog. Hunched at the distracted Orion’s feet is the small constellation of Lepus the hare.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Orion Entourage as seen at 9 p.m. January 7, 2016. Created using Stellarium
Orion and the head of Taurus photograph by myself January 4, 2016 at 11:30 p.m. It’s a stack of 5 untracked 20 second exposures.
Limiting magnitude is about 8, so you’re seeing stars you’d see with binoculars. The glow off to the left s from Traverse City, the center of which is 6 miles away to my northeast. I’m looking south here to get out of the glow, so Orion is more upright. I didn’t quite make it. My southwest through northwest is the darkest.
As you can probably guess I’ve got a new camera for my birthday/Christmas, a Canon EOS Rebel T5, and I’m investigating its astrophotographic capabilities. So expect some more “new” actual photographs on these posts.
01/04/2016 – Ephemeris – Some named stars in Orion and how to remember them
Ephemeris for Monday, January 4th. The Sun will rise at 8:20. It’ll be up for 8 hours and 55 minutes, setting at 5:15. The Moon, 2 days past last quarter, will rise at 3:49 tomorrow morning
Now that the Moon has fled let’s turn to the dark skies of winter and the magnificent constellation of Orion the hunter. At 9 p.m. he’s not yet completely upright in the southeast at 9 p.m. His seven bright stars make him easy to spot, starting with his belt of three stars in a straight line angling down to the left. It is inside a rectangle framing his shoulders and knees, leaning now to the left. The bright reddish star at the upper left corner is Betelgeuse, which according to a certain movie one shouldn’t say three-time in a row. The other shoulder star is a name familiar to Harry Potter fans, Bellatrix, though there’s nothing Lestrange about it. The lower right star is the bright blue-white Rigel. All in all a very impressive constellation.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Some of Orion’s star names. Orion at 9 p.m. January 4, 2016. Created using Stellarium.
12/15/2015 – Ephemeris – Procyon the star that’s “Before the dog”
Ephemeris for Tuesday, December 15th. The Sun will rise at 8:13. It’ll be up for 8 hours and 49 minutes, setting at 5:02. The Moon, 3 days before first quarter, will set at 9:48 this evening.
Visible low in the east at 9:30 p.m. appears the star Procyon to its lower left 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 9 tonight. Procyon is a star much like Sirius but is 32% farther away. It’s 11.4 to Sirius’ 8.6 light years away.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Procyon, Sirius and the stars of winter. Created using Stellarium
In the above chart, beside the constellation lines, we have the grid of right ascension, from lower left to upper right; and declination, from upper left to lower right. right ascension lines are like longitude on the Earth, while declination lines are latitude lines. They are tipped because I don’t live at either the equator or one of the poles. As the Earth rotates the Sun, stars and planets slide westward in the direction of the declination lines. Note that Sirius is closer to the horizon than Procyon. Also that Sirius is west of the 7 hour right ascension line. (Take my word for it.) Procyon is east of that line, thus Sirius is west of Procyon.
Other cool things can be seen in the chart. Note the declination line that touches the horizon at the east compass point and runs just above Orion’s belt. It is 0º declination, or the celestial equator. It extends to the west compass point on the western horizon. The Sun on the equinoxes will rise due east and set due west. The 6 hour right ascension line runs past Betelgeuse in Orion. At 23½º north declination, near Castor’s big toe in Gemini is where the Sun appears on the first day of summer, the summer solstice.
P.S. It was cloudy and rainy the last two days. Didn’t see a Geminid meteor again this year, keeping my record intact.
11/20/2015 – Ephemeris – Finding the bright stars of November
Ephemeris for Friday, November 20th. The Sun will rise at 7:46. It’ll be up for 9 hours and 24 minutes, setting at 5:10. The Moon, 1 day past first quarter, will set at 2:17 tomorrow morning.
The Moon is beginning to brighten up the sky making constellation spotting somewhat difficult, so I thought we’d look for the brightest stars. High in the west are the three stars of the Summer Triangle. At the bottom in the southwest is Altair, the first of these to set. A bit north of west the brightest, Vega. Highest in the west is Deneb, which won’t officially set for those Interlochen northward. Low in the south is the loneliest star Fomalhaut. In the northeast is the winter star Capella, which also doesn’t set for the IPR listener area, but spends summer nights hiding behind hills and trees in the north. Low in the east is the last of our bright stars, Aldebaran in Taurus the bull, which will be playing hide and seek with the Moon next week.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The bright first magnitude stars of autumn shown for 8 p.m. November 20, 2015. If you are closer to your time meridian, we’re 43 minutes behind ours, you will see two more bright stars in the east: Red Betelgeuse and blue-white Rigel. Created using Stellarium.
Bob Moler's Ephemeris Blog 