Archive

Posts Tagged ‘Big Dipper’

04/19/2018 – Ephemeris – The Big Dipper’s stars Mizar and Alcor

April 19, 2018 Leave a comment

Ephemeris for Thursday, April 19th. The Sun rises at 6:51. It’ll be up for 13 hours and 41 minutes, setting at 8:32. The Moon, 3 days before first quarter, will set at 12:47 tomorrow morning.

The most interesting star in the Big Dipper is Mizar and its dim companion Alcor. It is the second star from the end of the handle, where the bend in the handle takes place. Folks with good vision can see the dimmer star right next to Mizar. In ancient times it was used as an eye test for visual acuity for warriors as such it was known as the “Horse and the Rider”.

Mizar is second magnitude, in the second rank of star brightness invented by the Greek astronomer Hipparchus in the 2nd century BC. He ranked stars in 6 classes, from first magnitude for the brightest to 6th for the dimmest visible to the naked eye. Alcor comes in at 4th magnitude. It does suffer a bit by being close to Mizar which is 6 times brighter.

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

Addendum

The Big Dipper with Mizar & Alcor

The Big Dipper, almost overhead at 10 p.m. April 19 with Mizar and Alcor pointed out. Created using Stellarium.

Telescopic Mizar and Alcor

A view of Mizar and Alcor as seen in a telescope. Mizar is itself a binary star. In actuality both components of Mizar and Alcor are spectroscopic binaries, which are too close to split, but their presence is detected by their Doppler motions with spectrographs. Created using Stellarium.

Advertisements

04/09/2018 – Ephemeris – Follow the arc to Arcturus

April 9, 2018 Comments off

Ephemeris for Monday, April 9th. The Sun will rise at 7:09. It’ll be up for 13 hours and 11 minutes, setting at 8:20. The Moon, 1 day past last quarter, will rise at 4:40 tomorrow morning.

The fourth brightest night-time star is now up in the east. It is Arcturus, a bright star with an orange hue. It can be found otherwise by finding the Big Dipper and tracing out and extending the curve of the handle and remembering the line “Follow the arc of the handle to Arcturus”. To remember the name of the star and how to find it. Arcturus is about 37 light years from us and is moving quite rapidly across the sky, compared to most stars, though one would not notice it to the naked eye in one’s lifetime. Arcturus is slightly more massive than our Sun, and about 7 billion years old, and is entering its red giant stage of life after using all the hydrogen fuel in its core. Our Sun, being slightly less massive will survive on hydrogen a bit longer.

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

Addendum

Arc to Arcturus

Look high in the east on a spring evening to follow the arc of the Big Dipper’s handle to Arcturus. Created using Stellarium ans GIMP.

Categories: stars Tags: ,

02/13/2018 – Ephemeris – The Big Dipper as a pointer to other stars and constellations

March 13, 2018 Comments off

Ephemeris for Tuesday, March 13th. The Sun will rise at 7:58. It’ll be up for 11 hours and 47 minutes, setting at 7:46. The Moon, 4 days before new, will rise at 6:42 tomorrow morning.

With the Big Dipper up in the northeastern sky it is a sign that spring is coming. At 9 p.m. The Big Dipper can be used to find other stars and constellations. The Big Dipper’s most famous function is in locating Polaris the North Star. It’s a good way of finding directions at night. The altitude of Polaris, that is angle above the horizon, will give one’s approximate latitude north of the equator. Another constellation that can be found is Leo the lion. It is rising in the east in the evening, but it can also be found from the Big Dipper by imagining that a hole were drilled in the bottom of the bowl to let the water leak out. It would fall on Leo’s back. The Big Dipper can be used to find two more stars, but they have not yet risen.

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

Addendum

The Big Dipper

The Big Dipper points to Polaris, the, North Star, and to Leo the lion at 9 p.m., March 13th. In another hour the 4th brightest night-time star Arcturus will appear above the eastern horizon pointed to by the arc of the handle of the Big Dipper. We’ll revisit the Big Dipper next month when Arcturus and Spica will also be found by the use of the Big Dipper. Created using Stellarium and Libre Office.

03/12/2018 – Ephemeris – The Fisher is rising as spring approaches

March 12, 2018 Comments off

Ephemeris for Monday, March 12th. The Sun will rise at 8:00. It’ll be up for 11 hours and 44 minutes, setting at 7:45. The Moon, 4 days past last quarter, will rise at 6:05 tomorrow morning.

Now in the evening the Big Dipper has moved up in the northeast. The Anishinaabek peoples around the Great Lakes, like the Ottawa and Chippewa saw instead of a dipper or a bear: Ojiig the Fisher. It’s a magical weasel-like creature who, with some animal friends, brought summer to the Earth. The story is too long to relay here, but my telling of it is here. For his trouble he was slain, and was placed among the stars of the sky by the Great Spirit Manitou where we see him today. His blood is said to paint the trees with the fall colors. However as the Fisher rises in the northeast in late winter and early spring it is a signal for the maple trees to bring forth their sweet sap.

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

Addendum

The Fisher rising

Finding the Big Dipper and the Fisher at 9 p.m., March 12, 2018. Click on the image to enlarge. Created using Stellarium and GIMP.

The Anishinaabek constellation drawings are from Ojibwe Sky Star Map Constellation Guide  by Annette S. Lee, William Wilson, Jeffrey Tibbets and Carl Gawboy available locally and online.  They are part of the latest editions of Stellarium, a free planetarium program.  Links to it are on the left.  Other information and links are available within the Sky Lore tab.

Here’s one of the links: http://www.nativeskywatchers.com/.  It also contains links to Lakota star maps and lore.

02/13/2018 – Ephemeris – Looking out the thin side of the Milky Way’s disk

February 13, 2018 Comments off

Ephemeris for Fat Tuesday, February 13th. The Sun will rise at 7:46. It’ll be up for 10 hours and 22 minutes, setting at 6:08. The Moon, 2 days before new, will rise at 7:07 tomorrow morning.

With Orion and the winter stars grabbing our attention in the south, let’s look to the northeast to southeast where the stars are not as many, and with the exception of the Big Dipper and some other stars, not as bright. The inner stars of the Big Dipper are part of a sparse star cluster only about 80 light years away. The reason for the sparseness is that here we are looking out the thin side of the Milky Way’s disk.  It will be our spring sky. To the west is the autumn evening skies. The thick part of the disk runs from the south-southeastern horizon, to just west of the zenith to the northwestern horizon. The reason the Milky Way isn’t as bright as the summer sections, is that we are looking away from the center to the outer spiral arms. We are in a small arm with the Great Orion Nebula.

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

Addendum

he dome of the sky

The dome of the sky at 9 p.m. February 13, 2018 showing an enhanced Milky Way. Showing also the drop off in stars off that band to the east and west. Click on image to enlarge.  Created using Stellarium.

Our place in the Milky Way.

Our place in the Milky Way. Note that we appear to be in a barred spiral galaxy.  The arms are numbered and named.  3kpc is the 3 kiloparsec arm. 1 parsec = 3.26 light years. The Sun is about 27,000 light years from the center. Credit NASA and Wikimedia Commons, via EarthSky.org

Our galactic neighborhood

Our galactic neighborhood on the Orion spur or arm. Credit R. Hurt on Wikimedia Commons, via EarthSky.org.

The summer and winter Milky Way viewing directions.

The summer and winter Milky Way viewing directions. During Spring and Autumn, we look out the sides to the universe beyond. Credit: NASA with annotations by Bob King at Universe Today.

 

11/09/2017 – Ephemeris – Cassiopeia the queen and her husband

November 9, 2017 1 comment

Ephemeris for Thursday, November 9th. The Sun will rise at 7:31. It’ll be up for 9 hours and 49 minutes, setting at 5:20. The Moon, 1 day before last quarter, will rise at 10:59 this evening.

The stars of the autumn skies hold forth now, but one prominent autumn constellation never leaves us, here in northern Michigan. Look high in the northeastern sky by 8 p.m. and you can find the W shaped constellation of Cassiopeia the queen. It is opposite the pole star Polaris from the Big Dipper, slinking low in the north-northwest. There’s a dim star that appears above the middle star of the W which turns the W into a very crooked backed chair. Above and left of Cassiopeia is a dim upside down church steeple shaped constellation of Cepheus the king. The Milky Way flows through a corner of Cepheus and Cassiopeia toward the northeastern horizon and through the constellation of Perseus the hero, and the bright star Capella in Auriga the Charioteer.

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

Addendum

Cassiopeia and friends

Cassiopeia and constellations along the Milky Way in the northeast these autumn evenings. (8 p.m. November 9, 2017). Click on image to enlarge. Created using Stellarium and GIMP.

10/17/2017 – Ephemeris – The Fisher paints the autumn leaves red

October 17, 2017 1 comment

Ephemeris for Tuesday, October 17th. The Sun will rise at 8:00. It’ll be up for 10 hours and 53 minutes, setting at 6:54. The Moon, 2 days before new, will rise at 6:35 tomorrow morning.

This morning, if it’s clear the red planet Mars will appear just to the right of the thin crescent Moon. Mars isn’t the only thing that’s red now. So are the maple leaves as we advance into autumn. The native Anishinaabek peoples have a story about how that came to be. Of how a magical weasel-like creature called the Fisher or Ojiig brought summer to the Earth from Skyland. For his trouble he was shot with an arrow in his only vulnerable spot, the tip of his tail. As he fell to Earth the Great Spirit, Manitou caught him and placed him in the sky where we see the Great Bear (Ursa Major) and the Big Dipper. Every autumn we see his tail swoop down to the ground where his tail paints the leaves red with his blood.

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

Addenda

The Moon and the morning planets this morning

The Mon with the morning planets

The Moon and Mars at 6:30 this morning October 17, 2017. Click on image to enlarge. Created using Stellarium.

At 00:21 UTC on the 18th Venus will be south of the Moon.  It will be visible from Asia.

The Fisher (Ojiig) paints the trees with the autumn colors

Autumn colors

Autumn colors. My image.

Fisher brushing his tail along the horizon

An animation of Fisher brushing his tail along the horizon on autumn nights. Click on image to enlarge. Created using Stellarium.

The constellation art is part of the latest versions of Stellarium. Ojibwe (Anishinaabek) constellation art by Annette S Lee and William Wilson from Ojibwe Sky Star Map Constellation Guide, ISBN 978-0-615-98678-4.

See the version of the story I learned:  The story of the Fisher Star.

There are other variations of the story, and other adventures of the Fisher.  Perform an Internet search for: Fisher or Fisher Star or Ojiig.