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Posts Tagged ‘Polaris’

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.

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08/28/2017 – Ephemeris – Polaris the North Star

August 28, 2017 1 comment

Ephemeris for Monday, August 28th. The Sun will rise at 7:00. It’ll be up for 13 hours and 25 minutes, setting at 8:25. The Moon, 1 day before first quarter, will set at 12:19 tomorrow morning.

The bright star Polaris is a very important star. It is also known as the North Star and the Pole Star. Its unique position is nearly directly at the zenith at the Earth’s north pole, making it a very important navigational star. It’s about 40 minutes of arc, or about one and a third Moon diameters away from the extension of the Earth’s axis into the sky. As a rule of thumb, it’s angular altitude above the northern horizon is approximately one’s latitude, and it stands about at the due north compass point. Polaris is found using the Big Dipper, using the two stars at the front of the dipper bowl to point to it. It’s located at the tip of the handle of the very dim Little Dipper, which this time of year in the evening appears to standing on its handle.

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

Addendum

Polaris Finder Chart

Polaris finder chart for 10 p.m., August 28th. Created using my LookingUp program

Rotation of the sky around Polaris

Animation of the rotation of the sky around Polaris on the night of August 28/29, 2017. Created using Stellarium and Filmora.

I’ve left the constellation lines off.  The Big Dipper is seen easily as is Cassiopeia’s “W” opposite it around the stationary Polaris.

 

 

05/26/2016 – Ephemeris – Polaris the North Star

May 26, 2016 Comments off

Ephemeris for Thursday, May 26th.  Today the Sun will be up for 15 hours and 12 minutes, setting at 9:16, and will rise tomorrow at 6:03.   The Moon, 3 days before last quarter, will rise at 1:02 tomorrow morning.

The star Polaris is perhaps the most important star in the northern hemisphere sky.  That’s because it is nearly over the Earth’s north pole.  It’s also called the North Star or the Pole Star.  Polaris can be found by using the two stars at the front of the bowl of the Big Dipper,  These two stars, we call Pointer Stars do point very accurately to Polaris.  It is not the brightest star as some think, but a brighter than average star in a most unique position in the sky.  During the lifetimes of those now living Polaris will be getting slowly closer to the pole.  It won’t reach it, but in 100 years will begin to recede from the pole.  The altitude of Polaris in degrees approximately equals ones latitude.

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

Addendum

How to fing Polaris

Looking North at the Big Dipper pointing at Polaris. Created using my Looking Up program.

Polaris and the pole

Closeup of Polaris and the Celestial North Pole. The declination lines are 1 degree apart. Created using Cartes du Ciel (Sky Charts).

08/18/2015 – Ephemeris – The autumn queen is rising

August 18, 2015 Comments off

Ephemeris for Tuesday, August 18th.  The Sun rises at 6:48.  It’ll be up for 13 hours and 55 minutes, setting at 8:44.   The Moon, half way from new to first quarter, will set at 10:31 this evening.

A look to the northeast at 10 p.m. or later will reveal a letter W pattern of stars.  This is the constellation of Cassiopeia the queen.  Cassiopeia is so far north that it never sets for us in Michigan.  It is opposite the pole star Polaris from the Big Dipper.  So as the Big Dipper is rotating down the sky in the northwest, Cassiopeia is rotating up in the northeast.  The pivot is the star Polaris, the north star.  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 Cassiopeia is a dim church steeple shaped constellation of Cepheus the king.  The Milky Way flows through Cassiopeia and a corner of Cepheus and up through Cygnus, and on to the south.

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

Addendum

Cassiopeia

Cassiopeia and nearby constellations mentioned in the above program. Created using Stellarium.

03/27/2015 – Ephemeris – The North Star, Polaris

March 27, 2015 Comments off

Ephemeris for Friday, March 27th.  The Sun will rise at 7:33.  It’ll be up for 12 hours and 30 minutes, setting at 8:03.   The Moon, at first quarter today, will set at 3:49 tomorrow morning.

Tonight we turn our eyes northward to Polaris, the North Star.  It is the closest bright star to the north pole of the sky.  It appears nearly stationary as all the other stars appear to revolve around it as the Earth rotates.  Some folks, think that Polaris is the brightest star in the sky.  It’s not.  It is a good solid second magnitude star, about the brightness of a Big Dipper star.  The Big Dipper can be used to point to it, by using the two stars at the front of the bowl.  Polaris is at the end of the handle of the Little Dipper.  The Little Dipper has four dim stars in its rather oddly bent handle and back of its bowl.  The two stars at the front of the bowl of the Little Dipper are Kochab and the dimmer Pherkad, which are also called the Guard Stars or the Guardians of the Pole.

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

Addendum

Polaris finder chart

How to find Polaris. The grid is the equatorial grid showing the proximity to the pole. Created using Stellarium.

08/22/2014 – Ephemeris – Cassiopeia Rising

August 22, 2014 Comments off

Ephemeris for Friday, August 22nd.  The sun rises at 6:53.  It’ll be up for 13 hours and 43 minutes, setting at 8:36.   The moon, 3 days before new, will rise at 5:08 tomorrow morning.

Now in the northeastern sky at 10 p.m. or later is the constellation of Cassiopeia the queen, which looks like, in its current orientation like the letter W.  The Milky Way runs through it, if you trace the Milky Way from the zenith back to the northeast.  The milky band isn’t as bright here as it is in the teapot shaped Sagittarius to the south.  That’s because in looking to the south we are looking toward the star clouds of the dense spiral arm toward the center of the galaxy.  In Cassiopeia, and in the winter sky, we are looking out to the less populated galactic arms farther out from the center of the Milky Way.   Cassiopeia can be found using the Big Dipper.  A line from the star Mizar at the bend of the handle of the dipper through Polaris points to Cassiopeia.  Cassiopeia doesn’t set for us in northern Michigan.

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

Addendum

Finding Cassiopeia

Finding Cassiopeia using the Big Dipper or Ursa Major at 10 p.m. August 22, 2014 using the angle measurement tool as a pointer. Created using Stellarium.

06/02/2014 – Ephemeris – The Big Dipper points to other stars and constellations

June 2, 2014 Comments off

Ephemeris for Monday, June 2nd.  Today the sun will be up for 15 hours and 21 minutes, setting at 9:21.   The moon, 3 days before first quarter, will set at 12:41 tomorrow morning.  Tomorrow the sun will rise at 5:59.

The Big Dipper points to other stars and constellations.  Right now the Big Dipper is nearly overhead.  The front bowl stars point to Polaris, the North Star which never seems to move in the sky.  The handle can be used to find two stars.  First follow the arc of the handle away from the bowl to find the fourth brightest night time star Arcturus in the base of the kite shaped constellation of Boötes.  Straighten the arc to a spike and continue to the south and you will come to the bright blue-white star Spica in Virgo the virgin.  Don’t confuse it with reddish Mars to the right of it now.  You can remember these stars with the phrase “Follow the arc of the handle to Arcturus and then spike to Spica”

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

Addendum

Big Dipper

The Big Dipper can be used to point to other stars and constellations in the spring sky. Credit: My LookingUp program.