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Posts Tagged ‘Pleiades’

12/15/20187 – Ephemeris – Taurus, Bullish on Winter

December 15, 2017 1 comment

Note:  The title of this post I’ve taken from an article I wrote for the December 1999 issue of the Stellar Sentinel, the monthly newsletter of the Grand Traverse Astronomical Society, which I will reprint with some tweaks, as the addendum to this post.  Winter will arrive in six days, though I’m not particularly bullish on it, but it fits the constellation I’m talking about today.

Ephemeris for Friday, December 15th. The Sun will rise at 8:12. It’ll be up for 8 hours and 50 minutes, setting at 5:02. The Moon, 3 days before new, will rise at 6:25 tomorrow morning.

Low in the east-southeast at 9 p.m. is the constellation of Orion the giant hunter. Above him is Taurus the bull. His face is a letter V shape of stars lying on its side with the bright orange-red star Aldebaran at the bottom tip of the V as its angry blood-shot eye. Orion is depicted in the sky facing him with club in one hand and a shield in the other the approaching and in some depictions charging Taurus. The V of stars is a star cluster called the Hyades. The Pleiades are in his shoulder above. Taurus, in Greek mythology, was the guise the god Zeus when he carried off the maiden Europa. Europa’s still with him, sort of, as the intriguing satellite with a buried ocean orbiting Zeus’ Roman equivalent the planet Jupiter.

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

Addendum

Taurus and Orion

Three views of Taurus the bull and Orion the hunter for about  p.m. in December.

Hyades and Pleiades

The Hyades (lower left) and the Pleiades (upper right). My photograph from many years ago BD (Before Digital).

The first constellation of winter to appear is probably a toss-up between Auriga the charioteer and Taurus the Bull. Auriga never quite disappears, or at least Capella its brightest star is circumpolar and never quite sets here in Northern Michigan. But Auriga sneaks up slowly in the northeast. Taurus on the other hand makes a grand entrance on autumn evenings preceded by the Pleiades, the Seven Sisters star cluster.

Taurus’ brightest star is Aldebaran, the bull’s angry bloodshot eye. It is at the left tip of a letter V of stars that is the bull’s face. Above the V are single stars that form the tips of its very long horns. Other stars below form the front legs of this beast. That’s it. Only the front part of the bull appears in the sky. In its shoulder are the Pleiades.

According to Greek mythology Taurus represents the god Zeus, the Roman Jupiter, who, in the disguise of a bull abducted the beautiful maiden Europa. This isn’t the only celestial disguise of Zeus. Cygnus is the disguise of Zeus in the famous Leda and the swan affair.

The Pleiades and the Hyades, the V-shaped star cluster of Taurus’ head also have their places in Greek Mythology. The Hyades and Pleiades are half sisters of each other who share Atlas as their father. But it is the Pleiades which are more prominent and have more stories about them. It is the Pleiades that are pursued by Orion the hunter, the central constellation of winter. And since the Pleiades are west of Orion it does appear that Orion continues to chase them around and around the sky daily. To the Kiowa Indians the Pleiades were also young maidens. As the story goes they were being chased by a large bear. The Great Spirit placed them on what we know today as Devil’s Tower in Wyoming to keep them out of reach of the bear. It is said that even today the sides of this tower show the scars of the bear’s claws. Devil’s Tower was the prominent landmark in the movie Close Encounters of the Third Kind. To the Anishinaabek native peoples around here the Pleiades is the “Hole in the Sky” or the seven sweating stones that are heated for the sweat lodge ceremony.

What do we know about Taurus today? Aldebaran is an orangish giant star which lies at a distance of 65 light years. It doesn’t belong to the Hyades, which is about 151 light years away. Aldebaran’s diameter is 40 times the Sun’s, about the diameter as the orbit of Mercury. It’s only 1.7 times tha mass of the Sun. Aldebaran shines at 153 times the Sun’s output.

Aldebaran appears to be part of the Hyades cluster, but it is less than half the distance to this most important star cluster. Though less prominent as the Pleiades, the Hyades is the most important star cluster in the heavens. The reason is because the Hyades was until recently the only star cluster close enough to get an accurate distance measurement by direct means. That direct means is parallax, measuring the shift of the star’s position in the sky due to the earth’s changing position in orbit of the Sun. The Hipparcos satellite has been refining these parallaxes over the past few years. Its measurement of the distance of the Hyades cluster is 151 light years give or take a bit less than a light year. The Hyades distance is the basis for all more distant measurements to the ends of the known universe.

The Hyades is a good binocular object with over 100 stars visible. The cluster actually overflows the binocular’s field of view. This cluster is also known as the Taurus Moving Cluster because its stars are receding towards a point northeast of Orion’s Betelgeuse.

Of course the splashiest part of Taurus is the Pleiades. For people with good vision 6 or more stars can be seen. I can see 4 or 5 stars and fuzz, which are unresolved stars. Many, who see the Pleiades for the first time, think the tiny pattern of stars is the Little Dipper. The stars do indeed look like a tiny dipper, with a nice bowl and a sawed off handle. And that’s what I call it: the Tiny Dipper. The big surprise of the Hipparcos distance measurements is the distance of the Pleiades. The generally accepted distance was about 410 light years. Hipparcos measured 375 light years. This means that the stars of the Pleiades are somewhat dimmer than believed before. Pleiades prior measurement was based on photometric or brightness measurements with the stars of the Hyades and other stars of the same type and known brightness and distance. So it turns out in the case of the Pleiades that the former measurements weren’t as accurate as thought, and means we have more to understand about stellar evolution as it relates to star brightness. Or perhaps Hipparcos is wrong. And interesting debate and more measurements are sure to follow.

The age of the Pleiades is thought to be around 100 million years, young compared to the Sun’s 4.6 billion years. Long exposure photographs and some telescopes can still spot the remaining wisp’s of the nebulae they were born from. The material is probably dust simply reflecting the light of the stars in the cluster.

Taurus is a great constellation to scan with a pair of binoculars.

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11/10/2017 – Ephemeris – The North Taurid Meteors are reaching peak this weekend

November 10, 2017 1 comment

Ephemeris for Friday, November 10th. The Sun will rise at 7:32. It’ll be up for 9 hours and 46 minutes, setting at 5:19. The Moon, at last quarter today, will rise at 12:07 tomorrow morning.

One of the little known meteor showers for most of us are the North and South Taurid meteor showers. The shower that will reach peak this weekend is the North Taurids. They may show only 5 an hour when their radiants are overhead, but they are reported to be very bright. The radiant, the place where the meteors will appear to come from is just south of the Pleiades, will be up just about all night. Saturday night the Moon will rise at 1:15 a.m. Sunday night it will rise at 2:21 a.m. Both Taurid meteor showers are thought to be related to Encke’s Comet, the periodic comet with a period of only 3.3 years, the shortest known. A posting on Space.com about this years shower talked about the possibility that one of these meteorites might reach the ground.

Space.com has an excellent article about the Taurid meteor showers:  https://www.space.com/34587-taurid-meteor-shower-guide.html

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

Addendum

Northern Taurid meteor radiant

Northern Taurid meteor radiant near the Pleiades in Taurus the bull. Note the face of Taurus, the letter V or stars and Aldebaran. The stars in the face without Aldebaran is a star cluster called the Hyades. Created using Stellarium.

11/06/2017 – Ephemeris – Taurus’ angry red eye, Aldebaran

November 6, 2017 1 comment

Ephemeris for Monday, November 6th. The Sun will rise at 7:27. It’ll be up for 9 hours and 57 minutes, setting at 5:24. The Moon, 3 days past full, will rise at 7:52 this evening.

Last night the Moon passed in front of or occulted the bright star Aldebaran. Above right of Moon tonight is Aldebaran the bright orange star with a V shape of other stars in the face of Taurus the bull. Aldebaran appears at the lower left tip of that letter V laying on it’s side. With the bright Moon, it might take binoculars to pull out the faint stars of the V. Aldebaran isn’t actually part of the group, called the Hyades star cluster. The cluster is about 153 light years away, while Aldebaran is 65 light years away. The star has an orange hue because its surface is cooler than the Sun’s. However Aldebaran is 44 times larger in diameter, and shines 425 times brighter than the Sun. The name Aldebaran means “Follower” because it follows the Pleiades star cluster above it.

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

Addendum

Aldebaran

Aldebaran in the Hyades (unlabeled), with also the Pleiades, unlabeled, at the top and the Moon. at 9 p.m., November 6, 2017. Created using Stellarium.

07/04/2017 – Ephemeris – Happy birthday America! Tomorrow morning Venus will appear near the Pleiades

July 4, 2017 1 comment

Ephemeris for Independence Day, Tuesday, July 4th. Today the Sun will be up for 15 hours and 27 minutes, setting at 9:30, and it will rise tomorrow at 6:03. The Moon, 4 days past first quarter, will set at 3:46 tomorrow morning.

This is the 241st anniversary of the signing of the Declaration of Independence. Venus is our morning star now, and back in 1776 it too was a morning planet, but a lot closer to the rising Sun, and harder to spot.

Tonight Venus will pass south of the famous Pleiades star cluster, so that tomorrow morning at about 4:30 it will be dark enough to see the Pleiades above and left of our brilliant Morning Star.

Planets to us appear as stars to the naked eye due to their distance, though they are close enough to appear as disks in small telescopes. Very few of the largest telescopes can ever see the disk of a star, other than the Sun,, and only if that star is really huge, like Betelgeuse in the winter constellation of Orion.

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

Addendum

Venus and the Pleiades

The eastern sky at 5 a.m. July 5, 2017 with the Pleiades above and left of Venus. Created using Stellarium.

We’ll be seeing the Pleiades in the evening sky in four months when summer is a memory.

July 4, 1776

The morning sky to the east and Venus about 20 minutes before sunrise that auspicious morning July 4, 1776 from Philadelphia. Created using Stellarium.

Excuse the fact that the landscape is the same in both images.

Betelgeuse disk

This is the disk of the star Betelgeuse in Orion. It is not an image from an optical telescope of an image created in submillimeter microwaves by the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. Credit: ALMA (ESO/NAOJ/NRAO)/E. O’Gorman/P. Kervella.

Betelgeuse, though it is 600 light years away has a radius of slightly more than the orbit of Jupiter.  The bump on the left side of the image may be a plume of gas erupting from the star.

04/21/2017 – Ephemeris – Mars is passing south of the Pleiades today

April 21, 2017 Comments off

Ephemeris for Friday, April 21st.  The Sun rises at 6:47.  It’ll be up for 13 hours and 47 minutes, setting at 8:35.  The Moon, 2 days past last quarter, will rise at 4:54 tomorrow morning.

Mars in its ever eastward trek through the constellations of the Zodiac is now just south of the Pleiades or Seven Sisters star cluster in the western evening twilight.  By 10 p.m. Mars will be 10 degrees above the western horizon.  That’s the width of a fist held at arm’s length.  Because of our location on the Earth, the setting sky is tilted, so Mars being south of the Pleiades is to the lower left of it.  The bright star Aldebaran, now brighter than Mars is to the left of it with the V-shaped star cluster called the Hyades, in mythology, half sisters of the Pleiades, filling out the face of Taurus the bull.  Mars will finally be overtaken by the Sun on July 26th.  After that it will spend more than a year to come closer to us than at any time since August 2003.

First star party of the year at the Sleeping Bear Dunes National Lakeshore

Tomorrow night the Rangers of the Sleeping Bear Dunes National Lakeshore and the Grand Traverse Astronomical Society will host a Star Party at the Dune Climb featuring the planet Jupiter, and the stars of spring.  It starts at 9 p.m.

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

Addendum

Mars passes the Pleiades

Mars and the Pleiades at 10 p.m. April 21, 2017. Aldebaran and the Hyades which is the face of Taurus the bull is to the left of them. Created using Stellarium.

Note that the nebulosity in the Pleiades exists, but is not visible to the naked eye.

03/16/2017 – Ephemeris – Curly Tail, The Great Underwater Panther

March 16, 2017 Comments off

Ephemeris for Thursday, March 16th.  The Sun will rise at 7:52.  It’ll be up for 11 hours and 57 minutes, setting at 7:50.  The Moon, half way from full to last quarter, will rise at 12:03 tomorrow morning.

The Anishinabek people of the Great Lakes Region, which includes the Ottawa, Chippewa and Ojibwe Indians have two constellations of winter that I know of.  The first is The Winter Maker which uses many of Orion’s stars plus Procyon the Little Dog Star.  It rises in the eastern skies in the evening as winter is beginning.  The second is the Curly Tail, the Great Underwater Panther.  Which uses the stars of Leo the lion’s backward question mark as its tail and the small knot of stars that are the head of Hydra the water snake below Cancer as its head.  I imagine this constellation was a warning to youngsters to keep off the thinning ice of spring, lest they fall in and be snatched by the great underwater panther that lives beneath the ice.

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

Addendum

Ojibwe constellations

An animated GIF rotating between an unannotated star field facing south at 10 p.m. March 16th.; Western constellation names and lines for Orion, Hydra, and Leo; Western constellation art, Ojibwe constellation names and lines; and Ojibwe constellation art. Created using Stellarium. The Ojibwe constellation art is supplied as part of the latest version of Stellarium.  Click on the image to enlarge.

The source for the Ojibwe constellation art is from Ojibwe Sky Star Map Constellation Guide (An introduction to Ojibwe Star Knowledge) by Annette S. Lee, William Wilson, Jeffrey Tibbetts, and Carl Gawboy, ISBN 978-0-615-98678-4.  The illustrations are by Annette S. Lee and William Wilson.  There is also a poster sized star map available.  It should be available in book stores locally, or at Amazon.  I found my copy at Enerdyne in Suttons Bay.

Also shown is the Pleiades, which to the Ojibwe is Hole in the Sky, which has to do with the Shaking Tent Ceremony.  The Pleiades is also known as the Sweating Stones, the heated stones used in the Sweat Lodge Ceremony.  In the later spring sky the Sweat Lodge itself is seen in the stars of the Western Corona Borealis.

Note:  As far as tribe names go:  Ottawa = Odawa, and Chippewa = Ojibwe.

02/24/2017 – Ephemeris – Winter star party at the Sleeping Near Dunes tomorrow night

February 24, 2017 2 comments

Ephemeris for Friday, February 24th.  The Sun will rise at 7:27.  It’ll be up for 10 hours and 56 minutes, setting at 6:23.  The Moon, 2 days before new, will rise at 6:53 tomorrow morning.

Tomorrow night the Grand Traverse Astronomical Society and the Rangers of the Sleeping Bear Dunes National Lakeshore will hold a star party at the Dune Climb parking lot from 7 to 9 p.m. but only if it is clear.  Last Saturday night it happened to be clear, so I went out there to do some photography of the heavens, and the sky was spectacular with the brilliant constellation Orion dominating the southern sky.  Its great star forming region, the Great Orion Nebula displaying its bright heart and wispy outer tendrils of gas and dust heading away from that nest of bright baby stars that are illuminating it. Venus is a shining beacon in the west until it sets into the dune.  We might even be able to spot the faint Zodiacal Light in the west.

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

Addendum

Orion

Orion in a 30 second exposure taken at the Sleeping Bear Dunes National Lakeshore Dune Climb February, 18, 2017 by Bob Moler. Click on image to enlarge a bit.

Centered on Perseus

Area of the sky from the Hyades and Pleiades on the left to the Double Cluster on the right. While processing the image for this post I discovered two possible meteor trails on the left and below center. A 2 minute exposure taken at the Sleeping Bear Dunes National Lakeshore Dune Climb February, 18, 2017 by Bob Moler. Click on image to enlarge and see all the deep sky goodies in it..