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Wally
2001-Oct-31, 04:33 PM
Today's USA TODAY's weather fact mentions the "Seven Sisters" and the fact they'll be at their Zenith tonight (although it didn't bother to say at what time). 2 things bothered me. 1) No where did it give the proper name of the Pleides star cluster, and 2) It went on to mention that the miyan's (sp) and other's viewed this occurrance as signaling some cataclysmic world event. Kinda bad timing considering world events, I thought. . .

MongotheGreat
2001-Oct-31, 05:27 PM
To my understanding, zenith is the point in the sky that is 90 degrees from the horizon at your location. What the heck does it mean that the Pleides will be at their zenith tonight? If it means that they will be at the highest point in the sky, that's not a one night occurrance. Maybe post a link to the article.

Wally
2001-Oct-31, 05:46 PM
On 2001-10-31 12:27, MongotheGreat wrote:
To my understanding, zenith is the point in the sky that is 90 degrees from the horizon at your location. What the heck does it mean that the Pleides will be at their zenith tonight? If it means that they will be at the highest point in the sky, that's not a one night occurrance. Maybe post a link to the article.




Good catch Mongo. "Zenith" was my bad. The paper reports that it'll be at it's "highest point" tonight (furthest north, I assume). The hardcopy didn't mention a time, but the website article says at midnight, along with the full moon nontheless. Link included below (if I do it right. . .). Still no attempt to call the the grouping by its proper name, however.

http://www.usatoday.com/weather/news/2001/2001-10-31-halloweenfullmoon.htm#more

aurorae
2001-Oct-31, 07:07 PM
If I read my software correctly, M45 is going to transit at a little after 1 am tonight. So it looks like it will be at it's highest in the south (I live in the northern hemisphere) not at midnight, but around 1 am.

But maybe I've got things set up wrong due to coming off daylight savings time.

Azpod
2001-Oct-31, 11:18 PM
From what I remember from astrology (yes, I was into that garbage when I was younger), a constellation is said to be at its zenith when it is directly overhead (or as close as it can get) at midnight. I am not familiar with the meaning of the "Seven Sisters" constellation (yes, it irked me that they didn't use its real name) from my time as an astrologer, but if what the article said is true, then I wouldn't doubt that there are plenty of people who will be in fearful expectation of the End of the World tonight.

Shame on them. There already is enough fear to go around, they didn't need to create more. /phpBB/images/smiles/icon_evil.gif

Silas
2001-Nov-01, 12:19 AM
I heard the same thing on CNN Headline News (yeah, it's on tv, but I don't watch, I just listen...) They gave the business about this being a "blue moon," and noted that this is the first full moon on Hallowe'en in 46 years (the next being in 2020.)

Then they said, "Coincidentally," the Seven Sisters would be overhead, and that the Seven Sisters were traditionally associated with respect for the dead.

Coincidentally? Only every year for the past and next millenium...

Nitpick? Yeah...

Silas

Ben Benoy
2001-Nov-01, 12:48 AM
May be by coincidentally, he meant that they are reaching their highest point (and so being as close to over head as possible) on Halloween, a night traditionally associated with dead people. So the coincidence wasn't that they would be there, but that they would be so high on this day.

Yeah, that was pretty obvious, but that's what I'm good at. The obvious. er.. ok.

My question is, do the aforementioned sisters ever actually dip below the horizen in the States? I just don't know how high they are, I guess..

Ok,

Ben Benoy

David Simmons
2001-Nov-01, 01:18 AM
On 2001-10-31 19:48, Ben Benoy wrote:

My question is, do the aforementioned sisters ever actually dip below the horizen in the States? I just don't know how high they are, I guess..



Could be subject to interpretation. The Pleiades are in Taurus which is one of the signs of the Zodiac and is on the celestial equator, sort of. So they are not visible part of the year.

In the Northern Hemisphere they rise above the horizon in the spring mornings and they set below the horizon in the autumn mornings.

Link Pleiades (http://education.yahoo.com/search/be?lb=t&p=url%3Ap/pleiades)

<font size=-1>[ This Message was edited by: David Simmons on 2001-10-31 20:19 ]</font>

James
2001-Nov-01, 01:22 AM
I'm surprised that my hometown newspaper got everything right.


A GOBLIN MOON TONIGHT

For the first time in 46 years, Halloween goblins can trick or treat by the light of a full moon. They won't get another chance until 2020.
Tonight's full moon will look like a jack-o'-latern as it rises, appearing orange at the horizon because it's seen through denser layers of the atmosphere.
Pleiades, or the Seven Sisters, a constellation associated with calamity, also will be at the top of tonight's sky.
The Aztecs and Mayans believed that the open cluster of stars, which looks like a cluster of grapes, would be overhead at midnight when the world ends.
The Seven Sisters and the full moon will be directly overhead at midnight.

CJSF
2001-Nov-01, 01:29 PM
Overhead at midnight WHERE? Local midnight or midnight per time zone? Does that mean the world will only end for the line of longitude that is at "midnight" when the Pleadies are at their highest point? Or just whatever timezone that is? Does the world end 3 timezones over?

grrrrrr........

CJSF

(OK, rant over)

Hat Monster
2001-Nov-01, 02:47 PM
Since when was the cluster a constellation?

Matherly
2001-Nov-01, 03:05 PM
Since the Greeks decided that it looked like something from mythology (in this case, the Seven Sisters)

I mean, why are ANY of the constillations constillations? Because ultimatly, somebody just decided they were.

(edit: yea, yea, I know more than just the Greeks thought it made a pretty constillation. but thats where 'Pleadies' comes from, so I used Greeks.)

<font size=-1>[ This Message was edited by: Matherly on 2001-11-01 10:06 ]</font>

Kaptain K
2001-Nov-01, 03:51 PM
FWIW

1) M45 is an open cluster (several hundred stars).

2) The Pleiades (Seven Sisters) is an asterism (the brighteast stars of M45, which are visable to the unaided eye).

3) the correct term for the highest point reached by a celestial object is *culmination*.

/phpBB/images/smiles/icon_smile.gif Nit-pickingly yours /phpBB/images/smiles/icon_smile.gif KK

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<font size=-1>[ This Message was edited by: Kaptain K on 2001-11-01 10:53 ]</font>

David Simmons
2001-Nov-01, 04:36 PM
On 2001-11-01 08:29, Christopher Ferro wrote:
Overhead at midnight WHERE?



It is possible that I'm screwed up. But, let's say the Pleiades are directly overhead at midnight in Greenwich, Eng. The star cluster stands still and the earth rotates. One hour later, a point 15 deg west of Greenwich will have the Pleiades directly overhead and it will be midnight there. And so on, and so on ...

This isn't strictly true if you can measure accurately enough because the earth will have traveled a few miles in its orbit in the intervening hour. Solar vs. sidereal and all that, but I'm pretty sure that wouldn't be noticeable.

Daylight savings, or British Summer Time, when imposed by local authorities, will change this by an hour here and there. You are on your own to account for that.

<font size=-1>[ This Message was edited by: David Simmons on 2001-11-01 11:39 ]</font>

Wally
2001-Nov-02, 11:53 AM
On 2001-11-01 10:05, Matherly wrote:
Since the Greeks decided that it looked like something from mythology (in this case, the Seven Sisters)

I mean, why are ANY of the constillations constillations? Because ultimatly, somebody just decided they were.

(edit: yea, yea, I know more than just the Greeks thought it made a pretty constillation. but thats where 'Pleadies' comes from, so I used Greeks.)

<font size=-1>[ This Message was edited by: Matherly on 2001-11-01 10:06 ]</font>


I think the point Hat Monster is making is that the news kees calling the Pleides a constellation, when in fact it's an open cluster in the constellation of Taurus (and therefore not a constellation of its own). Regardless, the news missed out on a great opportunity to educate common folk on what the Pleides actually is. They could have even suggested people take a peek at 'em thru some binoc's. It's pretty darn impressive that way!

James
2001-Nov-02, 12:04 PM
Guess nothing happened or we would have heard about it by now.

_________________
Calling evolution a religion is like calling baldness a hair color.

[edit: typing too damn early in the morning...]

<font size=-1>[ This Message was edited by: James on 2001-11-02 07:05 ]</font>

Matherly
2001-Nov-02, 01:03 PM
On 2001-11-02 06:53, Wally wrote:
I think the point Hat Monster is making is that the news kees calling the Pleides a constellation, when in fact it's an open cluster in the constellation of Taurus (and therefore not a constellation of its own).

But it is a constellation! A bunch of Greeks decided it was a long time ago (just like they decided a big W looking pattern was a B***h Queen). Now, it might also be an 'Open Cluster', but by any reasonable definition, it is a contellation.

Kaptain K
2001-Nov-02, 03:33 PM
But it is a constellation! . . .
No it is not!!! The Pleaides is an asterism consisting of the brightest members of the open cluster M45 in the constellation Taurus.

Just like the Big Dipper is an asterism consisting of seven prominent stars (plus a faint one) in the constellation Ursa Major.

Please. These things have precisely defined, accepted definitions. Calling the Pleaides a constellation is (by definition) *Bad Astronomy*. /phpBB/images/smiles/icon_rolleyes.gif /phpBB/images/smiles/icon_rolleyes.gif /phpBB/images/smiles/icon_rolleyes.gif

Matherly
2001-Nov-02, 03:52 PM
O.K., I'll bite.

What is the precisely defined definition of a constellation?

SeanF
2001-Nov-02, 04:42 PM
Yeah, come on, people. Calling the Pleaides a constellation is like calling Pluto a planet!

Sheesh!

/phpBB/images/smiles/icon_wink.gif

aurorae
2001-Nov-02, 06:46 PM
On 2001-11-02 10:52, Matherly wrote:
O.K., I'll bite.

What is the precisely defined definition of a constellation?



Well, in my Webster's, it says "any of 88 stellar groups named after and thought to resemble various mythological characters, inanimate objects, and animals."

I'd say the above isn't quite correct, because I think Berenice was supposed to have been a real person.

Anyway, here are the constellations:

http://www.seds.org/messier/map/map.html

http://www.dibonsmith.com/stars.htm

And here is an explanation:

Despite the many mentions of the stars in Greek and early Roman texts, by far the most thorough star catalogue from ancient times belongs to the Roman Ptolemy of Alexandria, who grouped 1022 stars into 48 constellations during the 2nd century A.D. Although Ptolemy's Almagest does not include the constellations which may only be seen from the southern hemisphere, it forms the basis for the modern list of 88 constellations officially designated by the International Astronomical Union. The influence of both the Greek and Roman cultures may be plainly seen; the myths behind the constellations date back to ancient Greece, but we use their Latin names.

Matherly
2001-Nov-02, 07:05 PM
{grins}

Sorry, no dice. It has to be a strictly defined and accepted definition.

I found this definition in the Cambridge International Dictonary of English:

"constellation
noun [C]
any of the groups of stars in the sky which seem from Earth to form a pattern, many of which have name, for example Leo

(often humorous) A constellation is sometimes used when describing a group of famous or admired people gathered in one place.
Gathered here tonight at this annual ceremony we have a whole constellation of film stars/actors/acting talent/directors."

(The link to that dictionary is here- http://dictionary.cambridge.org/ )

Looks like we still haven't found the definition that...err... definitivly sets which patterns of starts are true contellations.

********************************************
Edit to add an additional thought...

Y'know, there just might be someone here on this board who just happens to have a Ph.D in astronomy. Maybe he knows the asnwer to our predicament. /phpBB/images/smiles/icon_smile.gif

(And just to be sure he notices it I'm gonna flame him-)

HEY BA! YOUR MOTHER! SHE'S OLDER THAN YOU!!!! SO THERE!
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<font size=-1>[ This Message was edited by: Matherly on 2001-11-02 15:11 ]</font>

David Hall
2001-Nov-02, 09:24 PM
I think the idea is not that there is a precise definition of "constellation", but rather that the constellations have been precisely defined.

We can all agree I'm sure that constellations are simply groups of stars that we have assigned a certain pattern and name to. By that simple definition the Big Dipper and the Pleiades could both be considered constellations (though the Pleiades strikes me more as a deep-sky object), but they are not accepted as such by modern astronomy. The Big Dipper is just part of a larger "officially" accepted constellation. The Pleiades are just a cluster of stars in Taurus. Other cultures have had their own interpretations of the constellations, but we don't use them either.

Thus the Pleiades could be a constellation, but it's not currently thought of as one by modern society.

Here's a nice constellation FAQ I just found:

http://www.physics.csbsju.edu/astro/asp/constellation.faq.html
_________________
David Hall
"Dave... my mind is going... I can feel it... I can feel it." (http://www.occn.zaq.ne.jp/cuaea503/whatnots/2001_feel_it.wav)

<font size=-1>[ This Message was edited by: David Hall on 2001-11-02 16:26 ]</font>

aurorae
2001-Nov-03, 09:22 PM
On 2001-11-02 14:05, Matherly wrote:
Looks like we still haven't found the definition that...err... definitivly sets which patterns of starts are true contellations.


We've already stated that the constellatoins are officially defined by the IAU.

That is the internationally recognized body that standardized them.