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Posts Tagged ‘Canis Minor’

02/20/2020 – Ephemeris – The Winter Triangle

February 20, 2020 Comments off

Ephemeris for Thursday, February 20th. Today the Sun will be up for 10 hours and 41 minutes, setting at 6:17, and it will rise tomorrow at 7:34. The Moon, 3 days before new, will rise at 6:53 tomorrow morning.

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 equally invisible constellation of Monoceros the unicorn. The Summer Triangle has three bright stars with no other close competition. The Winter Triangle has 4 other bright stars near it. Any three of these would make a nice triangle. One of these stars, Betelgeuse has been the news recently because it is dimming to an unprecedented degree.

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

Addendum

Winter Triangle

The Winter Triangle. It enclose a pretty blank space where Monoceros the unicorn lies. Created using Stellarium with my annotations for the Winter Triangle. By the way, Betelgeuse is currently only as bright as Bellatrix, the star next to the “n” in Orion.

02/17/2020 – Ephemeris – A look at Orion and his hunting dogs

February 17, 2020 Comments off

Ephemeris for President’s Day, Monday, February 17th. Today the Sun will be up for 10 hours and 32 minutes, setting at 6:13, and it will rise tomorrow at 7:39. The Moon, 2 days past last quarter, will rise at 4:27 tomorrow morning.

The great winter constellation or star group Orion the Hunter, is located in the southern sky at 9 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 lower in the south facing Orion that appears to be begging. Canis Minor is just two stars found by extending Orion’s shoulder stars eastward where we find bright Procyon, the little dog star in the southeast.

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

Addendum

Orion and his hunting dogs

Orion and his hunting dogs with pointers as seen at 9 p.m. in mid February. Created using Stellarium.

12/19/2019 – Ephemeris – What does the bright star Procyon’s name mean?

December 19, 2019 Comments off

Ephemeris for Thursday, December 19th. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:04, and it will rise tomorrow at 8:16. The Moon, at last quarter today, will rise at 1:42 tomorrow morning.

Visible low in the east at 8:30 p.m. will appear the star Procyon, sometimes called the little Dog Star. It’s in the constellation of Canis Minor, the little dog. It will rise at 8:05 p.m. for the Traverse City Interlochen area. Yet to rise at that time is the Dog Star itself, Sirius, the brightest night-time star. It won’t rise until 8:40 p.m., 35 minutes later even though Sirius is west of Procyon. I bring this up because the name Procyon means Before the Dog. At our latitude Procyon rises before any part of Canis Major, the big dog, Canis Major, that Sirius is in the heart of. This is sensitive to one’s latitude. At the equator, say in Ecuador. Sirius would rise first due to its westerly position by 54 minutes. You see Procyon is also north of Sirius and that makes all the difference.

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

Addendum

Procyon rising before Sirius

Stars and constellations in the east at 9 p.m., about 4 hours after sunset, on December 19th. This only works for locations above 30 degrees north latitude. Created using Stellarium.

Procyon and Sirius will for observers located at 30º 30′ north latitude.  South of that latitude Sirius will rise first.

01/28/2019 – Ephemeris – The celestial unicorn

January 28, 2019 Comments off

Ephemeris for Monday, 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, 1 day past last quarter, will rise at 2:52 tomorrow morning.

Within a triangle bounded by stars Betelgeuse in Orion, Sirius in Canis Major and Procyon in Canis Minor, called the Winter Triangle appears a nearly starless patch of sky to the naked eye. In here is the constellation Monoceros, the unicorn. 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 also contains beautiful telescopic triple star system, Beta (β) Monocerotis.

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

Addendum

Monoceros

Monoceros finder chart animation. Created using Stellarium and GIMP.

Rosette Nebula

Rosette Nebula in the infrared from the Spitzer Space Telescope. Credit: NASA/JPL/Caltech

Hubble's Variable Nebula

Hubble’s Variable Nebula photographed appropriately enough by the Hubble Space Telescope. Credit: NASA/ESA and The Hubble Heritage Team (AURA/STScI).

Monoceros DSO finder chart

Looking at some faint objects in Monoceros. NGC 2239 is the star cluster in the center of the Rosette Nebula. The nebula itself is extremely faint. It shows in photographs, but I’ve never seen it visually. The green circle shows Beta Monocerotis, the triple star. All these stars are extremely blue-white hot. Created using Cartes du Ciel (Sky Charts).

Beta Monocerotis

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.

 

01/25/2019 – Ephemeris – Let’s find Orion’s hunting dogs

January 25, 2019 Comments off

Ephemeris for Friday, January 25th. Today the Sun will be up for 9 hours and 32 minutes, setting at 5:41, and it will rise tomorrow at 8:08. The Moon, 2 days before last quarter, will rise at 11:27 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 tilting toward the 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 low in the southeast facing Orion that appears to be begging. Canis Minor is just two stars found by extending Orion’s shoulder stars eastward where we find bright Procyon, the little dog star.

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

Addendum

Orion and his hunting dogs

Orion and his hunting dogs with pointers as seen at 9 p.m. in late January . Created using Stellarium.

12/18/2017 – Ephemeris – The little dog shall lead

December 18, 2017 1 comment

Ephemeris for Monday, December 18th. The Sun will rise at 8:14. It’ll be up for 8 hours and 49 minutes, setting at 5:03. The Moon is new today, and won’t be visible.

The constellation Orion has two hunting dogs. At 9 p.m. we’ll see one of them, the lesser dog, Canis Minor whose bright star Procyon is low in the East. Just two stars mark the constellation. Is it a dachshund or maybe a hot dog? The name Procyon means “Before the dog”, an odd title. It means that though east of Sirius, the bright dog star in Orion’s large dog, Canis Major, it rises before Sirius, due to its more northerly position in the sky. At 9 Sirius is just rising in the east-southeast. 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’ 8.6 light years. Procyon is at a distance of 11.46 light years.

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

Addendum

Procyon rising before Sirius

Stars and constellations in the east at 9 p.m., about 4 hours after sunset, on December 18th. This only works for locations above 30 degrees north latitude. Created using Stellarium.

03/23/2017 – Ephemeris – a single headed Hydra

March 23, 2017 Comments off

Ephemeris for Thursday, March 23rd.  The Sun will rise at 7:39.  It’ll be up for 12 hours and 19 minutes, setting at 7:59.  The Moon, 3 days past last quarter, will rise at 5:48 tomorrow morning.

In the southern evening sky can be found the constellation of Hydra the water snake.  Unlike the mythical monster Hercules fought of the same name this Hydra has but one head, which is its most distinctive part.  At 9 p.m. look to the south.  The head of Hydra is located directly to the left of Procyon the bright star in Orion’s little dog Canis Minor, and to the right of the star Regulus in Leo.  Hydra’s head is a small distinctive group of 6 stars that make a loop and the snake’s slightly drooping head.  At that time the sinuous body of Hydra sinks below the horizon in the southeast.  As it gets later in the evening the rest of Hydra’s body will slither to just above the southeastern horizon below the planet Jupiter this year and the bright star Spica in the constellation of Virgo.

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

Addendum

Hydra

Finding Hydra animation for 9 p.m. March 23rd 2017. Created using Stellarium.  Click on image to enlarge.

02/16/2017 – Ephemeris – The Winter Circle

February 16, 2017 Comments off

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

The Winter Circle of 1st magnitude stars. Created using my LookingUp program.

01/26/2017 – Ephemeris – Is it a dachshund or a hot dog?

January 26, 2017 Comments off

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

Orion and hunting dogs

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.

02/16/2015 – Ephemeris – The little Dog Star

February 16, 2016 Comments off

Ephemeris for Tuesday, February 16th.  The Sun will rise at 7:42.  It’ll be up for 10 hours and 29 minutes, setting at 6:12.   The Moon, 1 day past first quarter, will set at 3:45 tomorrow morning.

Procyon is  the bright star to the east or left of Betelgeuse in the sky tonight, which puts it in the east-southeast at 9 tonight.  Procyon is the brightest of the two stars in Canis Minor, Orion’s little hunting dog.  Procyon is sometimes called the Little Dog Star for that reason.  The Dog Star Sirius is a ways below and right of it.  The name Procyon means “Before the Dog”, because Procyon, though east of Sirius, rises before it due to its more northerly position.  This only works if one is north of 30 degrees north latitude.  South of that, Sirius rises first.  Procyon is a white star 11 and a half light years away, 3 light years farther than Sirius, and like Sirius it has a faint white dwarf companion.  It’s a bit less than half the Sun’s age.

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

Procyon, Sirius and the stars of winter. Created using Stellarium

Note that at their rising Procyon is higher in the sky than Sirius.

There are some grid lines on the chart.  The ones running from lower left to upper right are lines of declination, which are like latitude lines on the Earth.  On this chart they are 10º apart.  The line that intersects the horizon at the east compass point is the celestial equator.  It will meet the western compass point at the horizon.  As the Earth rotates the stars and planets will move westward in the direction of these declination lines.  The lines that run from upper left to lower right are hour lines of right ascension.  Here they are 15 degrees or one hour apart,  The Earth rotates 360º in a sidereal* day.  360 divided by 24 hours gives 15º an hour.  So the celestial sphere of stars and planets will slide 15º westward in a sidereal hour.

*  A sidereal day, rotation with respect to the stars, is about 4 minutes shorter that the solar day, the day and time we keep based on the Sun.  The Sun moves about one degree eastward each day, so the rotation has to catch up that one degree each day.  The rotation of one degree takes 4 minutes.  I’ll let you work that one out for yourself.