Archive
01/28/2016 – Ephemeris – This post has gone to the dogs
Ephemeris for Thursday, January 28th. The Sun will rise at 8:06. It’ll be up for 9 hours and 38 minutes, setting at 5:45. The Moon, 3 days before last quarter, will rise at 10:42 this evening.
The great winter constellation or star group Orion the Hunter, is located in the southern sky at 9:30 p.m. His elongated rectangle of a torso is vertical. In the center of the rectangle are three stars in a line that make his belt. As a hunter, especially one of old, he has two hunting dogs. The larger, Canis Major can be found by following the three belt stars of Orion down and to the left. There lies the brilliant star called Sirius, also known as the Dog Star. It’s in the heart of a stick figure dog facing Orion that appears to be begging. The smaller dog can be found by extending a line through Orion’s shoulder stars to the left. We find a bright star called Procyon. It and one other star make up the hot-dog shaped constellation of Canis Minor, the little dog.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Orion and his hunting dogs revealed in animation. Created with Stellarium and GIMP.
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.
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.
02/16/2015 – Ephemeris – The Winter Circle
Feb 16. This is Bob Moler with Ephemeris for President’s Day, Monday, February 16th. The sun will rise at 7:42. It’ll be up for 10 hours and 30 minutes, setting at 6:12. The moon, 2 days before new, will rise at 6:25 tomorrow morning.
The winter skies are blessed with more first magnitude stars than any other season. That’s a full one-third of the total are seen is a relatively small area. Six of these stars lie in a large circle centered on the seventh. This circle is up at 9 p.m. Starting high overhead is Capella in Auriga the charioteer. Moving down clockwise is 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, lowest of these stars in the south-southeast. Moving up and left is Procyon in Canis Minor, Above Procyon is Pollux in Gemini the twins. All these are centered on Betelgeuse the bright red star in Orion’s shoulder.
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
01/21/2014 – Ephemeris – Orion’s hunting dogs
Ephemeris for Tuesday, January 21st. The sun will rise at 8:11. It’ll be up for 9 hours and 24 minutes, setting at 5:36. The moon, 3 days before last quarter, will rise at 11:23 this evening.
The great winter constellation or star group Orion the Hunter, is located in the south-southeastern sky at 9 p.m. His elongated rectangle of a torso is almost vertical. In the center of the rectangle are three stars in a line that make his belt. As a hunter, especially one of old, he has two hunting dogs. The larger, Canis Major can be found by following the three belt stars of Orion down and to the left. There lies the brilliant star called Sirius, also known as the Dog Star. It’s in the heart of a stick figure dog facing Orion that appears to be begging. The smaller dog can be found by extending a line through Orion’s shoulder stars to the left. We find a bright star called Procyon. It and one other star make up the hot-dog shaped constellation of Canis Minor, the little dog.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Orion and his hunting dogs with pointers as seen at 9 p.m. on January 21, 2014. Created using Stellarium.
12/27/2013 – Ephemeris – The star Procyon: “Before the Dog”
Ephemeris for Friday, December 27th. The sun will rise at 8:18. It’ll be up for 8 hours and 50 minutes, setting at 5:08. The moon, 2 days past last quarter, will rise at 3:48 tomorrow morning.
Yesterday I talked about the brilliant star Sirius, the dog star pointed to by the stars of the belt of Orion. Today we’ll look at another dog star. Procyon, the bright star in Canis Minor, the lesser dog. It is pointed to by the top two stars in the Orion rectangle Bellatrix and Betelgeuse. One of the translations of Procyon means “Before the Dog”. This seemingly odd title is explained that even though Procyon is east of Sirius and all things being equal, well at least latitude or declination the eastern star should rise after the western star. However Procyon is north of Sirius and if one is sufficiently north of the equator, the eastern most star can rise first. This is what happens. Procyon is a bit farther away than Sirius and isn’t quite as bright either.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Procyon is already up as Sirius rises. Procyon also sets after Sirius. Created using Stellarium.
Note: Stellarium approximates atmospheric extinction, that is dims objects when they are near the horizon an effect due to looking through more of the Earth’s atmosphere when looking close to the horizon. That’s why Sirius looks rather fainter than in yesterday’s image.
02/04/2013 – Ephemeris – The celestial unicorn
Ephemeris for Monday, February 4th. The sun will rise at 7:57. It’ll be up for 9 hours and 58 minutes, setting at 5:56. The moon, 1 day past last quarter, will rise at 3:41 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 southeastern sky at 9 p.m. bounded by Orion on the right, Canis Major, the great dog below and Canis Minor, the little dog to the left. Unfortunately for observers without optical aid Monoceros, though large, 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 telescope it is a feast of faint nebulae or clouds of gas and dust, the birth place of stars, including the red rose of the Rosette Nebula, and the strange and tiny Hubble’s Variable Nebula. It has a wealth of wonders below the surface so to speak.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Moniceros the unicorn. Created using Stellarium.
01/29/2013 – Ephemeris – Procyon, the Little Dog Star
Ephemeris for Tuesday, January 29th. The sun will rise at 8:04. It’ll be up for 9 hours and 43 minutes, setting at 5:47. The moon, 3 days past full, will rise at 8:52 this evening.
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 maybe a hot dog? 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 at a distance of 11.46 light years. 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
Winter Circle and Jupiter with Procyon to the far left. Created using Stellarium.
12/20/11 – Ephemeris – Procyon, the “Little Dog Star”
Tuesday, December 20th. The sun will rise at 8:15. It’ll be up for 8 hours and 48 minutes, setting at 5:04. The moon, 3 days past last quarter, will rise at 4:45 tomorrow morning.
Visible low in the east at 9 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. Procyon is a star much like Sirius but farther away. [It’s 11.41 to Sirius’ 8.6 light years away. And like Sirius it even has a small white dwarf star in its system.]
* Times, as always are for the Traverse City/Interlochen area of Michigan. Text in brackets was omitted in the audio program due to time constraints.
Addendum
Procyon, Sirius and the stars of winter. Created using Stellarium
The grid lines are right ascension and declination, analogous to longitude and latitude on the earth. Looking eastward the right ascension lined run from the upper left to the lower right. Thus Procyon is definitely farther east than Sirius.
Bob Moler's Ephemeris Blog 