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imported_Jerry
2003-Nov-27, 06:30 AM
take a good look at the Pleiades (M45) they are very easy to find, a small group of stars that look a lot like a small version of the Big Dipper sometimes called the seven sisters, the seven Atlantic Sisters and even the Seven evil Sisters! The Pleiades is a open cluster made up of over 200 star s that lies about 400 Light Years from us but with most back yard Scopes you may only see upwards to 45 stars, Binoculars are the best at seeing the full size of the cluster; using a telescope using the lowest power you might even see some nebulosity around some of the young blue stars. Most of these stars are less than 50 million years old, think about it for a minute, the dinosaurs were said to have died off around 65 million years ago. Now I want all of you to add to this subject, I have left a whole bunch of really neet little things!

Haglund
2003-Nov-27, 10:15 PM
The Pleiades is a great object indeed, and yes I saw the nebula gas around the stars while observing through a telescope, although it was very faint. 50 million years? That's just a brief period of time in universe!

seeker372011
2003-Nov-27, 11:19 PM
Last night was fine -in the North and East especially -for observing at my suburban Sydney location and the Pleides were particularly good through my 7 x 50 binoculars..

Not far away are the Hyades, which also made good binocular targets last night. Less than half as far away (150 light years to be precise) as the Pleides, so this cluster covers a significant area of the sky. The Hyades is a very easy cluster to locate, because its stars form the triangular 'face' of the bull, behind the 'eye' star Aldebaran. (To me it looks like a giant V with a big red jewel embedded in it),

I had trouble viewing the Andromeda galaxy which is also not too far away because of trees but the Orion nebula was exceptionally good viewing even through a binoculars. I felt I could make out the stars in the Trapezium but this may have been my imagination!! :)

Such nights are few and far between in the city unfortunately.

seeker



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Agro
2003-Nov-28, 04:22 AM
Hi Jerry,

I agree - I cannot see the nebulosity with my scope even at low magnification. However it is clear (on a good night) though in my 12x40 binos.
The young age of the stars in the cluster suggests to me (perhaps in my ignorance!) that the nebular material is not the result of stars aging and sloughing off their outer layers, so I guess is must be the remains of the stuff that the stars were made from. Is that correct?
Is the nebulosity so faint because there is little of it left or is it faint because the radiation from it is not (mainly) in the visible spectrum? ;)

chicagoastronomer
2003-Nov-29, 10:38 AM
Fellow Astronomers...

I enjoyed reading about one of my favorites, The Seven Sisters, or the Pleiades Open Star cluster. In one of my earlier astronomical newsletters, I sent out a piece on the Pleiades. I thought I would share this with you all, but I wish I could include the beautiful graphics and prints in the post, but this shall do. A fellow Chicago astronomer sent me info on the Subaru symbol, in that it represented the Pleaides. Stuff I never knew about.

Hope you enjoy the background as much as I did writing about it.

Respectfully,

Joe
Chicago Astronomer----------------------------------------------


Vol.1 - #17

Fellow Chicago Astronomers...

"Many a night I saw the Pleiads, rising thro' the mellow shade,
Glitter like a swarm of fireflies tangled in a silver braid."


- Alfred, Lord Tennyson

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While saying my goodbyes last night after a late night rendezvous of eat, drink and merryment, we had noticed that the Chicago night skies were incredibly clear, dark and deep. I was asked about a particular smudge high in the SouthEastern sky. With the Moon in the east, and my hands quite full, I pointed out that the smudge was in fact the Seven Sisters, better known as the Pleiades Open Star Cluster - (M45).

The Pleiades star cluster is a conspicuous object in the night sky with a prominent place in ancient mythology, (See below). The cluster contains hundreds of stars, of which only 6 are commonly visible to the unaided eye. The stars in the Pleiades are thought to have formed together around 100 million years ago, making them 1/50th the age of our sun, and they lie some 425+- light years away. From our perspective they appear in the constellation of Taurus, and the cluster is above and to the right of Orion the Hunter as one faces south. It transits, reaches its highest point in the sky around midnight in November, and 8pm in January.






A beautiful star cluster, they stand out like white-blue jewels burning in a cloud mist, for all to enjoy in a low-powered telescopic eyepiece or binoculars.


This is an Hubble image of the clouds or nebula around the star cluster - (Courtesy of NASA).

Below is a short explanation of the mythology of the Pleiades...


F. E. Fillebrown engraving of The Dance of the Pleiades by Elihu Vedder
Courtesy of Art Connections

In Greek mythology the Pleiades are seven sisters and children of gods Atlas and Pleinoe. They were attendants of Artemis, had violet hair and were relentlessly pursued by the lusty and amorous hunter Orion. They were rescued by the gods from the unwanted attentions of Orion, and turned into stars.

From the Monache Indians in central California. A group of women who love onions more than their husbands enter the sky to become the Pleiades. Their husbands pursue them and become the constellation Taurus. There are many variations on the Pleiades myth from cultures all over the world. Below are two good links to myth sources.

http://www.kitezh.com/sevensisters/pleiades.htm

http://www.pleiade.org/pleiades_02.html

Amateur Astronomer Douglas emails in more information on the Pleiades Open Star Cluster (M45), in regards to my last astronomical topic:

Doug writes: "Also known as Subaru in Japanese which is why the logo for the
Japanese car of that name has seven stars."
I did some research on Doug's insight, and lo and behold:

*************

Note that there are only six (6) stars instead of seven showing on the auto symbol,
common mythology says:
The Lost Pleiad
The `lost Pleiad' legend came about to explain why only six are easily visible to the unaided eye
This sister is variously said to be Electra, who veiled her face at the burning of Troy, appearing to mortals afterwards
only as a comet; or Merope, who was shamed for marrying a mortal; or CelŠno, who was struck by a thunderbolt.

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Now of course, I would never drive anything but pure 1960's muscle and iron, but it is indeed nice that someone named a car after the Pleiades. If anyone wishes to yank their symbol from their vehicle, I'll proudly attach it to my telescope. Thanks to Douglas for the enlightenment. Till next time... Chicago Astronomer

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Got to get to bed eariler.

Till next time....

Joe
Chicago Astronomer

imported_Jerry
2003-Nov-29, 11:17 PM
Pleiades is commonly known as M 45 among amateur astronomers. Melotte 22 is another designation. The brighter stars (beginning at the upper left-hand side of the dipper and down to its end) are Asterope, Taygeta, Celaeno, Maia, Electra, Alycone, Merope, Pleione, and Atlas. This dipper-shaped asterism is also known as The Seven Sisters and consists of six larger nebulous bright, blue-white stars, plus, many smaller and fainter stars that can be seen with either binoculars or a telescope.

It has been discovered that the nebulosity surrounding M45 is not associated with the cluster, but is passing through it. The cluster and the nebulae both have different radial velocities and proper motion, and, in addition the nebula is a reflection type and not an emission type as found in M42. Some recent studies present evidence that contradicts this traditional view of the Pleiades. It is now suspected that this is an older cluster than formerly believed, and that the surrounding nebulosity is not a source of new stellar condensation.( Astronomical Journal, vol.87, p. 1507, 1982

I have read stories that call them the seven Halloween sisters because they were so evil. And the Atlantic sisters were to have lead sailors to their deaths. They were thought to be pretty nasty in some of the stories. Ron wrote that he has also heard of the Pleiades being connected with Indian tribes long ago. Claimed that 7 special women all died at the same time and went into the sky to become the Pleiades and watch over the land for the Indians. Some tribes worshipped them as Gods.


TRIVIA - According to Bob Berman, who wrote Secrets of the Night Sky, the ancient Japanese name for the Pleiades was "Subaru." Apparently, six Japanese car companies had merged to build the Subaru in the early 1950's and had named their car after the Pleiades.

Another good topic, how many can you see with you’re naked eye?

zephyr46
2003-Dec-02, 01:17 AM
Does anyone know of an online Java 3d model of the pleiades?

imported_Jerry
2003-Dec-03, 06:02 PM
Her you go zephyr46, I think these might help some!


Some of this is far-out stuff ... beware:

http://www.igd.fhg.de/~wkresse/pern/

Yep, Dragonriders of Pern. Very interesting use of the Hipparcos catalog data. Really!

http://www.rssd.esa.int/gaia/interactive/m...tml/sec13p1.htm

... is a 3D "image" you form by staring at the monitor and relaxing your eyes to focus at infinity ... works, though ...

http://www.booklocker.com/books/1282.html

... is an eBook (PDF) for $15 that shows you how to make your own 3D models of the solar system, the Pleiades, etc. ...

http://javanovae.chez.tiscali.fr/java/pleiades.htm

... is a Map of the Pleiades rendered via a Java applet (I suppose you could get the applet and data from the author) ... I saved the best for last!