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Posts Tagged ‘Cepheus’

09/18/2020 – Ephemeris – A closer look at Cepheus the king’s most famous star

September 18, 2020 Comments off

This is Ephemeris for Friday, September 18th. Today the Sun will be up for 12 hours and 20 minutes, setting at 7:46, and it will rise tomorrow at 7:27. The Moon, 1 day past new, will set at 8:52 this evening.

There’s a faint constellation in the northeast above the W shaped constellation of Cassiopeia. It’s a nearly upside down church steeple of a constellation called Cepheus the king, and husband of queen Cassiopeia. Cepheus’ claim to astronomical fame is that one of its stars, Delta (δ) Cephei, is the archetype for the important Cepheid variable stars. Delta is the bottom most of a trio of stars at the right corner of the constellation. In the early 20th century Henrietta Leavitt discovered that Cepheids in the nearby galaxy the Large Magellanic Cloud varied in brightness with a period that was related to their average brightness. This meant that Cepheids could be used as standard candles to measure the great distances to other galaxies.

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

Addendum

Cassiopeia and Cepheus finder animation

Cassiopeia and Cepheus finder animation looking in the northeast at 9 pm or about an hour after sunset in mid-September. Created using Stellarium and GIMP.

Delta Cephei (circled) finder for mid-September at 9 pm or about an hour after sunset looking northeast. The brighter stars are marked by their Bayer Greek letters. Numerical designations are Flamsteed numbers. Created using Cartes du Ciel (Sky Chart).

Delta_Cephei_lightcurve

Light Curve of Delta Cephei. The pulsation period is 5.367 days. Credit: ThomasK Vbg – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=13887639

09/17/2020 – Ephemeris – Finding Cassiopeia the queen and Cepheus the king

September 17, 2020 Comments off

This is Ephemeris for Thursday, September 17th. Today the Sun will be up for 12 hours and 24 minutes, setting at 7:48, and it will rise tomorrow at 7:25. The Moon is new today, and won’t be visible.

The stars of the autumn skies are slowly replacing the summer stars from the east. Look midway up in the northeastern sky in the evening and you can find the W shaped 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 handle of Big Dipper. There’s a dim star that appears above the middle star of the W which turns it into a very crooked backed chair, Cassiopeia’s throne. Above and left of Cassiopeia is a dim upside down church steeple shaped constellation of Cepheus the king, her husband. The Milky Way flows through Cassiopeia toward the northeastern horizon. She is a character in an autumn star story with five other constellations.

For my retelling of the Greek myth that links these autumn constellations click here.

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

Addendum

Cassiopeia and Cepheus finder animation

Cassiopeia and Cepheus finder animation looking in the northeast at 9 pm or about an hour after sunset in mid-September. Created using Stellarium and GIMP.

 

Ephemeris Extra – The Great Star Story of Autumn

September 18, 2019 Comments off
Autumn Star Story Constellations

The constellations of the great star story of autumn. Looking southeast on October 31 at 10 p.m. Created using Stellarium.

The great star wheel of the sky rolls on. In the evening sky gone are the stars of spring, and going are the southern stars of summer. In the morning sky before sunrise the stars of an early winter evening.

A constant in both skies are the stars of autumn: rising in the evening and setting in the morning. In no other part of the sky do so many constellations take part in a single story

The constellations, as seen above are Cepheus, Cassiopeia, Andromeda, Perseus, Pegasus, and Cetus. And their story goes like this:

In distant Ethiopia a crisis was brewing. King Cepheus and Queen Cassiopeia were at wits end as how to stop it. A giant sea monster named Cetus was ravaging the country’s coastal cities destroying them and devouring the inhabitants.

The king and queen consulted the temple oracle as to what happened and what could be done to save their country. The oracle intoned gravely that the fault was Cassiopeia’s. Suddenly the queen knew what happened. Cassiopeia was very beautiful and she had vainly boasted to all who could hear that she was more beautiful than even the sea nymphs, the lovely daughters of the sea god Poseidon.

The sea nymphs had heard of Cassiopeia’s boast and complained to their father. Poseidon, like any father, was angered, and being a god was able to do something about. Being a god means never having to say your sorry when you do something really mean. He loosed the monster Cetus upon the Ethiopians.

The oracle said that to appease the monster and Poseidon Cassiopeia would have to sacrifice her daughter the Princess Andromeda to the monster. That is how young Andromeda was chained to the rocks on the sea shore to await her doom…

Far away in ancient Greece a wedding was about to take place between the beautiful Princess Danaë and King Polydectes. Danaë’s son Perseus, fathered by Zeus, but that’s another story, wasn’t too happy about the proposed union, and Polydectes wanted the boy gone.

When Perseus asked Polydectes what he wanted for a wedding gift, he said, “I want the head of Medusa.” The boy immediately and foolhardedly agreed to get it for him.

Merdusa, it turns out, was one of three sisters, the Gorgons, who had snakes for hair. They were so ugly that one glimpse of them would turn the beholder to stone. Medusa was the only mortal one.

Luckily Perseus had the favor of the god Hermes and Athene. They armed him with Hermes’ winged sandals, a helmet that made him invisible, a pouch that would expand to hold an object of any size, a shiny mirror shield, and a sword.

Thus armed Perseus was told to find the Graiae or the gray women, who could tell him where the lair of the Gorgons was. They were three in number and shared but one eye and one tooth among them which they passed from one to another to use.

The Graiae refused to help Perseus. But he was able to force them to help by snatching their one eye while it was being passed from one to another. They told him that the Gorgons dwelt in the shore of the river Ocean at the edge of the world in perpetual twilight.

In approaching the lair of the Gorgons Perseus put on the helmet of invisibility. He approached Medusa stepping backwards, cautiously peering only at Medusa’s indistinct image in his shield. Perseus then swept his sword in a backhanded way and managed to sever Medusa’s head. It is said that Athene guided his hand.

Amazingly, springing full grown from Medusa’s blood was the winged white stallion Pegasus. After placing Medusa’s head in the pouch, Perseus mounted Pegasus for the trip home.

Cruising high in the sky over the Ethiopian coast Perseus spotted a horrific sight. There far below the beautiful Andromeda, in chains; her screams reaching his ears. Then he spotted why she was screaming. A short distance away, crawling out of the surf was the monster Cetus, heading towards Andromeda. Perseus immediately sizes up the situations and swooped with Pegasus down to a spot between Andromeda and the monster. Then, burying his head in his shoulder drew out the head of Medusa from the pouch and held it in front of Cetus. The head was as lethal in death as in life, and the monster was promptly turned to stone. Replacing the head in the pouch, Perseus freed Andromeda. They flew off to, well supposedly, live happily ever after.

Oh yes. Perseus did present the head of Medusa to his step father Polydectes. He, of course, was also turned to stone when he laid eyes on it.

There you have it a story connecting the autumn constellations of Cepheus, Cassiopeia, Andromeda, Perseus, Pegasus and Cetus.

Cepheus is a dim church steeple of a constellation. Its dim star Delta is a variable star, the prototype of an important class of distance measuring stars called Cephieds in its honor. Cassiopeia is the famous W shaped constellation that along with Cepheus doesn’t set at our latitude.

Perseus looks to me more like the cartoon roadrunner than a hero. As the ancients saw him, he is holding the head of Medusa, whose still glittering eye is the star Algol, a variable star which ghastly winks at us every 2 days and 21 hours.

Andromeda’s modern claim to fame is the great galaxy that lies beyond her stars, the Great Andromeda Galaxy which has the designation M31. The galaxy is faintly visible to the unaided eye on dark nights. The farthest you can see without optical aid. The galaxy lies some 2.5 million light years away.

Pegasus can be easily found by the square of stars the form his body. It’s called the Great Square of Pegasus.

What can be said about Cetus. It now represents a whale, not a monster. Its star Mira, which means “Wonderful”, slowly varies in brightness over 330 days from a star barely visible in binoculars to a 2nd or 3rd magnitude star.

Look up on an autumn evening and recapture the wonder the ancients had as they looked upward at the stars.

11/05/2018 – Ephemeris – Cassiopeia the Queen

November 5, 2018 Comments off

Ephemeris for Monday, November 5th. The Sun will rise at 7:26. It’ll be up for 9 hours and 59 minutes, setting at 5:26. The Moon, 2 days before new, will rise at 6:00 tomorrow morning.

The stars of the autumn skies are replacing the summer stars from the east. Look in the northeastern sky by 7 p.m. and you can find the W shaped 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. There’s a dim star that appears above the middle star of the W which turns it into a very crooked backed chair, Cassiopeia’s throne. Above and left of Cassiopeia is a dim upside down church steeple shaped constellation of Cepheus the king, her husband. The Milky Way flows through Cassiopeia toward the northeastern horizon and through the constellation of Perseus the hero, which kind of looks, to me anyway, like the cartoon roadrunner.

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 5). Click on image to enlarge. Created using Stellarium and GIMP.

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.

1122/2016 – Cepheus the king and its one really important star

November 22, 2016 Comments off

Ephemeris for Tuesday, November 22nd.  The Sun will rise at 7:49.  It’ll be up for 9 hours and 18 minutes, setting at 5:08.  The Moon, 1 day past last quarter, will rise at 1:56 tomorrow morning.  |  There’s a faint constellation in the north above Polaris.  It’s a nearly upside down church steeple of a constellation called Cepheus the king, and husband of queen Cassiopeia the W shaped constellation right of it.  Cepheus’ claim to astronomical fame is that one of its stars, Delta (δ) Cephei, is the archetype for the important Cepheid variable stars.  Delta is in a trio of stars at the top corner of the constellation, and the one on the right.  In the early 20th century Henrietta Leavitt discovered that Cepheids in the nearby galaxy the Large Magellanic Cloud varied in brightness with a period that was related to their average brightness.  This meant that Cepheids could be used as standard candles to measure great distances to other galaxies.

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

Addendum

Cepheus

Cepheus animated finder chart for 8 p.m. November 22, 2016. Created using Stellarium and GIMP.

Delta Cephei finder chart

Delta Cephei finder chart. This is the same orientation as the chart above, but created using Cartes du Ciel (Sky Charts). A green line points to Delta (δ) Cephei.

A word about star designations in the chart above.  In general only the brightest stars have proper names.  And those usually come from antiquity, and most of those are Arabic.  Star designations which are Greek lower case letters come from Johann Bayer’s Uranometria star atlas from 1603.  He designated the stars by order of brightness.  In constellations with a lot of stars he moved to the Latin alphabet after running out of Greek letters.  These were, of course, naked eye stars; the atlas being produced a few years before the invention of the telescope.  Stars with numbers are Flamsteed designations from John Flamsteed’s 1725 star catalog.  He numbered his stars from west to east in a particular constellation, but only those stars that could be seen from Great Britain.  A single star can have many catalog designations.  For instance the bright star Vega in Lyra the harp is Alpha (α) Lyrae, Bayer designation; 3 Lyrae, Flamsteed designation; HD 172167, Henry Draper catalog; BD +38 3238,  Bonner Durchmusterung, a German catalog; HIP 91262, Hipparcos catalog, and so on.

 

10/03/2016 – Ephemeris – Cassiopeia the celestial queen, and a look at Venus with the Moon

October 3, 2016 Comments off

Ephemeris for Monday, October 3rd.  The Sun will rise at 7:43.  It’ll be up for 11 hours and 34 minutes, setting at 7:18.  The Moon, 3 days past new, will set at 8:55 this evening.

The stars of autumn are in the northeastern to southeastern part of the evening sky.  Look half way up the sky in the northeast at 9 p.m. and you can find the W shaped constellation of Cassiopeia the queen.  Cassiopeia never sets for us in Michigan.  It is opposite the pole star Polaris from the Big Dipper.    Above Cassiopeia is a dim church steeple shaped constellation of Cepheus the king.  The steeple is toppled to the left.  The Milky Way flows through Cassiopeia and through a corner of Cepheus to the bright star Deneb in Cygnus the Swan, or Northern Cross, overhead. Below Cassiopeia it flows through the constellation of Perseus the hero, which kind of looks like a chicken, to the bright star Capella near the horizon.

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

Addendum

The crescent Moon will appear above Venus tonight.

Venus and the Moon

Looking very low in the west-southwest at 7:38 p.m., 20 minutes after sunset, October 3, 2016. The thin crescent Moon will appear about 4 degrees 15 minutes (8 1/2 moon diameters) above Venus. Created using Stellarium.

Cassiopeia and the Milky Way

Cassiopeia with Cepheus, Cygnus and Perseus in the Milky Way in the northeastern sky. Created using Stellarium.

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.

09/10/2012 – Ephemeris – The constellation Cepheus the king

September 10, 2012 Comments off

Ephemeris for Monday, September 10th.  The sun will rise at 7:16.  It’ll be up for 12 hours and 45 minutes, setting at 8:01.   The moon, 2 days past last quarter, will rise at 2:25 tomorrow morning.

The stars of autumn are taking over the eastern evening sky as the equinox approaches.  Looking to the northeastern sky at 10 p.m. we find the W shaped constellation of Cassiopeia the queen.  It is opposite the pole star Polaris from the Big Dipper.  Above Cassiopeia is a dim church steeple shaped constellation of Cepheus the king.  The steeple is toppled to the left.  It also lies on the line between the bright star Deneb, the northeastern most star of the Summer Triangle and Polaris.  Cepheus is a king and the husband of the more notorious Cassiopeia.  The Milky Way flows through a corner of Cepheus.  One of its stars is Delta Cephei is the first of a type of variable star that have allowed us to measure distances to the galaxies.

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

Addendum

The constellation Cepheus.  Created using Stellarium.

The constellation Cepheus at 10 p.m. September 10th. Created using Stellarium.

Click image to enlarge.