Two astronomy questions

1. Are the constellations within the Milky Way?

2. Do we have a clue as to where the earth resides in the Milky Way?
I gather we are quite a ways from the dense center, but how far away?
(center? outer edge?)
Thanks,
-Tom

Hello Tom,

Tom wrote:

1. Are the constellations within the Milky Way?

I'm not sure what exactly is your question. If you are asking if the
bright stars that form the constellations lie in our galaxy, the answer
is "yes". If you are asking if the constellations lie only or
predominantly on the band of the night sky called the Milky Way, the
answer is "no".

2. Do we have a clue as to where the earth resides in the Milky Way?
I gather we are quite a ways from the dense center, but how far away?
(center? outer edge?)

This page will give you the answer you are looking for:

http://encyclopedia.thefreedictionary.com/Milky%20Way
http://img.thefreedictionary.com/wik...arp.250pix.jpg

Regards,

- Alex

"Tom" wrote in message
...
1. Are the constellations within the Milky Way?

The constellations have no astronomical significance. They are just
arbitrary sections of the night sky. The stars in a constellation can be any
distance from the earth (the closest star is about 4 light years away), and
the stars in a constellation are unrelated to each other and will be a
mixture of near and far objects. The only reason they are in the same
constellation is that they are in the same rough direction from Earth. Its
like you standing on your front porch and seeing your neighbour's kitchen
light, the lights from a shopping centre 1 km away, and the lights of the
city 10kms away and calling them a constellation because they are all in the
same direction. Indeed, a lot of the objects we see as stars are not even
really stars, they are nebula (collections of stars).

Having said that, with the naked eye there are only 3 objects that you can
see which are not part of the milky way - two sattelite galaxies of the
Milky Way called the Magellenic clouds, visible only in the southern
hemisphere, which look a bit like little bits of the Milky Way, and the
Andromeda galaxy which looks like an extremely faint star and is visible
only in the Northern Hemisphere.

So at a practical level all of the objects that you can see at night that
look like stars (with one tiny exception) are contained in the Milky Way.

-
2. Do we have a clue as to where the earth resides in the Milky Way?
I gather we are quite a ways from the dense center, but how far away?
(center? outer edge?)
Thanks,
-Tom



http://seds.lpl.arizona.edu/messier/more/mw.html

The Milky Way is about 50,000 light years in radius (depending upon how you
define the edge); we lie about 26,000 kms from the centre.

Peter Webb

"Alexander Avtanski" wrote in message
...
Hello Tom,

Tom wrote:

1. Are the constellations within the Milky Way?

I'm not sure what exactly is your question. If you are asking if the
bright stars that form the constellations lie in our galaxy, the answer
is "yes". If you are asking if the constellations lie only or
predominantly on the band of the night sky called the Milky Way, the
answer is "no".

Yes, I was wondering if the constellations were within a portion of
the Milky Way. Would some fainter stars within our view be outside
the MW alltogether, as in, on their own in the vast void?.

2. Do we have a clue as to where the earth resides in the Milky Way?
I gather we are quite a ways from the dense center, but how far away?
(center? outer edge?)

This page will give you the answer you are looking for:

http://encyclopedia.thefreedictionary.com/Milky%20Way
http://img.thefreedictionary.com/wik...arp.250pix.jpg

A pic is worth a thousand words. Thanks.
-Tom

"Tom" wrote in message
...

Yes, I was wondering if the constellations were within a portion of
the Milky Way. Would some fainter stars within our view be outside
the MW alltogether, as in, on their own in the vast void?.

Everything you see is in our own galaxy, except for one specific "star"
which is actually the Andromeda galaxy..

Keep in mind also that, with us being inside our own galaxy, most of the
stars we see are in the general neighborhood. For example, the 3 stars
that make up Orion's Belt aren't near each other, but they're all under 2000
light years or so away.

The galaxy is some 100,000+ light years across, so, it's rather like being
in a forest, we're not seeing the trees on the far side.

Also, keep in mind that when you see "maps" of our galaxy, they're often
largely theoretical. We don't really know the exact shape of the galaxy,
being inside of it. Looking towards the core it gets harder to
distinguish individual stars, and we don't see what's on the other side of
that.

There's an estimated 200-400 billion stars in our galaxy, so obviously we're
only seeing a fraction of that when we look in the night sky (or, what we're
seeing as one star is really multiple stars).

The Andromeda galaxy is one that we can see and surmise, in all likelihood,
our galaxy is shaped a lot like that....

we're an estimated 25,000-28,000 light years from the center of the galaxy.

Peter Webb posted:

Having said that, with the naked eye there are only 3 objects that you can
see which are not part of the milky way - two sattelite galaxies of the
Milky Way called the Magellenic clouds, visible only in the southern
hemisphere, which look a bit like little bits of the Milky Way, and the
Andromeda galaxy which looks like an extremely faint star and is visible
only in the Northern Hemisphere.

Actually, there are a few other objects which are not part of the Milky Way's
disk but which are visible to the unaided eye under good to excellent
conditions. The brightest globular star clusters (which, like the Magellanic
Clouds orbit the Milky Way) such as M13, M22, M4, 47 Tucanae (NGC 104), and
Omega Centauri are all visible to the unaided eye from a dark sky site.
Another galaxy visible to the unaided eye is the relatively nearby spiral
galaxy M33, which is fairly easy to see under 6th magnitude skies (ie: you can
see stars as faint as 6th magnitude). Under extremely good conditions from
dark moderate altitude sites, the more distant spiral galaxy M81 (mag. 6.9)
can sometimes be glimsed as a very faint star. As for the Andromeda galaxy,
it is visible from both the Northern hemisphere *and* large parts of the
Southern hemisphere, including Australia, southern Africa, and the northern
2/3rds of South America. It appears as a fuzzy star of about the 4th
magnitude, which isn't exactly all that bright, but isn't exactly a very faint
star either. Clear skies to you.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************

THE GALAXY SONG
By Python,M, et al.
Just remember that you're standing on a planet that's evolving
and revolving at 900 miles an hour,
It's orbiting at 19 miles a second, so it's reckoned,
the sun that is the source of all our power.
The Sun and you and me, and all the stars that we can see,
are moving at a million miles a day,
In the outer spiral arm, at 40,000 miles an hour,
of the Galaxy we call the Milky Way.
Our Galaxy itself contains 100 billion stars,
it's 100,000 light-years side-to-side,
It bulges in the middle, 16 000 light-years thick,
but out by us it's just 3 000 light-years wide.
We're 30,000 light-years from galactic central point,
we go round every 200 million years,
And our galaxy is only one of millions of billions
in this amazing and expanding universe.
The universe itself keeps on expanding and expanding,
in all of the directions it can whizz,
As fast as it can go, at the speed of light you know,
twelve million miles a minute, and that's the fastest speed
there is.
So remember, when you're feeling very small and insecure,
how amazingly unlikely is your birth,
Pray that there's intelligent life somewhere up in space,
because there's bugger all down here on Earth.




--
http://mysite.wanadoo-members.co.uk/jc_atm/



---
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On Wed, 28 Jul 2004 19:41:29 +0100, John Carruthers wrote:

THE GALAXY SONG
By Python,M, et al.


Ya got to love the Python!

John Carruthers wrote:

THE GALAXY SONG
By Python,M, et al.
[ ... ]

:-) This is the song that made me remember once for all the
sizes and distances around the Galaxy. The trouble is that when
the estimates change and I'm stuck with old data.

However, the more pressing problem right now is that I cannot
take the melody out of my head!!! It's your fault John! :-)
Time to some musical therapy. "Cats" should help. I usually
end up stuck with "Jellicle Cats" or "Macavity" but, hey,
that's better than a non-stop loop of The Galaxy Song!

- Alex

"John Carruthers" wrote in message
...
THE GALAXY SONG
By Python,M, et al.
Just remember that you're standing on a planet that's evolving
and revolving at 900 miles an hour,
It's orbiting at 19 miles a second, so it's reckoned,
the sun that is the source of all our power.
The Sun and you and me, and all the stars that we can see,
are moving at a million miles a day,
In the outer spiral arm, at 40,000 miles an hour,
of the Galaxy we call the Milky Way.
Our Galaxy itself contains 100 billion stars,
it's 100,000 light-years side-to-side,
It bulges in the middle, 16 000 light-years thick,
but out by us it's just 3 000 light-years wide.
We're 30,000 light-years from galactic central point,
we go round every 200 million years,
And our galaxy is only one of millions of billions
in this amazing and expanding universe.
The universe itself keeps on expanding and expanding,
in all of the directions it can whizz,
As fast as it can go, at the speed of light you know,
twelve million miles a minute, and that's the fastest speed
there is.
So remember, when you're feeling very small and insecure,
how amazingly unlikely is your birth,
Pray that there's intelligent life somewhere up in space,
because there's bugger all down here on Earth.




--
http://mysite.wanadoo-members.co.uk/jc_atm/

Thanks for the lyrics

there's a link to an mp3 version here
http://groups.yahoo.com/group/Meade4504Telescopes/


PS John, your 'Mendicant Astronomer' block has you located at
N 51d 14m 41s E 1d 18m 01s

Is the Easting once around the block and back again ?