Andromeda three times bigger than previously thought

Well there you go....now you know

http://pr.caltech.edu/media/Press_Releases/PR12703.html

On Tue, 31 May 2005 15:00:29 +0200
Charles D. Bohne wrote:

On Tue, 31 May 2005 10:37:24 +0100, Ray Vingnutte
wrote:
=20


Well there you go....now you know

http://pr.caltech.edu/media/Press_Releases/PR12703.html
=20
Thanks, Ray!!
C.
=20
=B0 Scott Chapman, from the California Institute of Technology, and
Rodrigo Ibata, from the Observatoire Astronomique de Strasbourg in
France, have led a team of astronomers in a project to map out the
detailed motions of stars in the outskirts of the Andromeda galaxy.
Their recent observations with the Keck telescopes show that the
tenuous sprinkle of stars extending outward from the galaxy are
actually part of the main disk itself. This means that the spiral
disk of stars in Andromeda is three times larger in diameter than
previously estimated.


Thats just the sort of info Darla could have given us without any fear
of us using it as a weapon, if she had then we would now all be going
WOOOOAAAAA it's all true.....

=20

Hi Ray That begs the question can we relate this with our Milky Way?
Should we now say Andromeda is 4 times bigger than the Milky way. I
wonder if it could be a little closer too bert

In message , Ray Vingnutte
writes


Well there you go....now you know

http://pr.caltech.edu/media/Press_Releases/PR12703.html


Thanks Ray.
The paper at http://xxx.lanl.gov/abs/astro-ph/0504164 says it's about
4 degrees across in the sky, eight times the apparent diameter of the
Moon.
--
Remove spam and invalid from address to reply.

On Tue, 31 May 2005 18:58:19 +0100
Jonathan Silverlight
wrote:

In message , Ray Vingnutte
writes


Well there you go....now you know

http://pr.caltech.edu/media/Press_Releases/PR12703.html


Thanks Ray.
The paper at http://xxx.lanl.gov/abs/astro-ph/0504164 says it's
about 4 degrees across in the sky, eight times the apparent diameter
of the Moon.

Thanks, can I ask how you find those papers, from the link I gave I
can't see how you get from that to the paper on the site you posted.

--
Remove spam and invalid from address to reply.

In message , Ray Vingnutte
writes
On Tue, 31 May 2005 18:58:19 +0100
Jonathan Silverlight
wrote:

In message , Ray Vingnutte
writes


Well there you go....now you know

http://pr.caltech.edu/media/Press_Releases/PR12703.html


Thanks Ray.
The paper at http://xxx.lanl.gov/abs/astro-ph/0504164 says it's
about 4 degrees across in the sky, eight times the apparent diameter
of the Moon.

Thanks, can I ask how you find those papers, from the link I gave I
can't see how you get from that to the paper on the site you posted.


Remarkably quickly.
I was expecting to have to do a search because it looked interesting,
but the press release has a link to Scott Chapman's home page at
http://www.astro.caltech.edu/~schapman/m31.html and that has a link to
"Want Details?" at http://www.astro.caltech.edu/%7Eschapman/halo.html.
From there to "THE BONUS: MEASURING THE HALO" at
http://www.astro.caltech.edu/%7Eschapman/halo.html and then to Ibata
et al. 2005 under "THE DISK". I've just noticed that the link to
Chapman's own paper at http://xxx.lanl.gov/abs/astro-ph/0506232
doesn't work!

On Wed, 1 Jun 2005 18:51:07 +0100
Jonathan Silverlight
wrote:

In message , Ray Vingnutte
writes
On Tue, 31 May 2005 18:58:19 +0100
Jonathan Silverlight
wrote:

In message , Ray Vingnutte
writes


Well there you go....now you know

http://pr.caltech.edu/media/Press_Releases/PR12703.html


Thanks Ray.
The paper at http://xxx.lanl.gov/abs/astro-ph/0504164 says it's
about 4 degrees across in the sky, eight times the apparent
diameter of the Moon.

Thanks, can I ask how you find those papers, from the link I gave I
can't see how you get from that to the paper on the site you posted.


Remarkably quickly.
I was expecting to have to do a search because it looked interesting,
but the press release has a link to Scott Chapman's home page at
http://www.astro.caltech.edu/~schapman/m31.html and that has a link
to "Want Details?" at
http://www.astro.caltech.edu/%7Eschapman/halo.html.
From there to "THE BONUS: MEASURING THE HALO" at
http://www.astro.caltech.edu/%7Eschapman/halo.html and then to Ibata
et al. 2005 under "THE DISK". I've just noticed that the link to
Chapman's own paper at http://xxx.lanl.gov/abs/astro-ph/0506232
doesn't work!

Thanks again, I'll keep eyes open next time.

Just saw on the news, missed most of it, about a five year long
simulation of the universe, can;t find any more about it yet, no doubt a
link will turn up in a while;-)

"Ray Vingnutte" wrote...
in message ...

Well there you go....now you know

http://pr.caltech.edu/media/Press_Releases/PR12703.html

'Lo Ray --

I just caught this... and i don't get it.

This says that it was previously thought that Andromeda
was only 70,000 to 80,000 ly in diameter, or somewhat
smaller in size than our Milky Way which "weighs in" at
about 100,000 ly across. And that now we believe that
Andromeda is 220,000 ly across.

When i was a kid i remember reading that Andromeda
was believed to be 2 or 3 times as big as the Milky Way.
And this was confirmed for me many years ago by the
SEDS website...

"Under "normal" viewing conditions, the apparent size of
the visible Andromeda Galaxy is about 3 x 1 degrees (our
acurate value, given above, is 178x63 arc minutes, while
NED gives 190x60'). Careful estimates of its angular
diameter, performed with 2-inch binoculars, by the French
astronomer Robert Jonckhere in 1952-1953, revealed an
extension of 5.2 times 1.1 degrees (reported by Mallas),
corresponding to a disk diameter of over 250,000 light
years at its distance of 2.9 million light years, so that this
galaxy is more than double as large as our own Milky Way
galaxy !"

Ref.: http://www.seds.org/messier/m/m031.html

So why do these people think that Andromeda is larger
than we've believed it to be ever since we found out that
it's a galaxy?

The funny thing is, when i looked at the title of this thread,
i went, "WOW, Andromeda is about 750,000 light years
across???"

We already *knew* Andromeda was about 220,000 ly
in diameter (which is actually 30,000 ly LESS than the old
SEDS figure). So what's the big fuss???

happy days and...
starry starry nights!

--
Space so scary, quite contrary,
How does your nothing grow?
A just as hairy corollary...
What makes your nothing flow?

Indelibly yours,
Paine http://www.savethechildren.org/

On Wed, 15 Jun 2005 15:40:42 GMT
"Painius" wrote:

"Ray Vingnutte" wrote...
in message ...

Well there you go....now you know

http://pr.caltech.edu/media/Press_Releases/PR12703.html

'Lo Ray --

I just caught this... and i don't get it.

This says that it was previously thought that Andromeda
was only 70,000 to 80,000 ly in diameter, or somewhat
smaller in size than our Milky Way which "weighs in" at
about 100,000 ly across. And that now we believe that
Andromeda is 220,000 ly across.

Well I would expect anything and almost everything to change, even the
size of our own galaxy maybe.


When i was a kid i remember reading that Andromeda
was believed to be 2 or 3 times as big as the Milky Way.
And this was confirmed for me many years ago by the
SEDS website...

See above comment ;-)


"Under "normal" viewing conditions, the apparent size of
the visible Andromeda Galaxy is about 3 x 1 degrees (our
acurate value, given above, is 178x63 arc minutes, while
NED gives 190x60'). Careful estimates of its angular
diameter, performed with 2-inch binoculars, by the French
astronomer Robert Jonckhere in 1952-1953, revealed an
extension of 5.2 times 1.1 degrees (reported by Mallas),
corresponding to a disk diameter of over 250,000 light
years at its distance of 2.9 million light years, so that this
galaxy is more than double as large as our own Milky Way
galaxy !"

Sounds all perfectly normal really, a lot of this is likely all subject
to change, there's no real firm consensus on the number of stars in our
own galaxy, figures vary and vary with all measurements I think. So it
would come as no surprise to find different values for all sorts of
things, it's just normal it seems.


Ref.: http://www.seds.org/messier/m/m031.html

So why do these people think that Andromeda is larger
than we've believed it to be ever since we found out that
it's a galaxy?

According to the article about 3,000 stars that were not
considered part of the main disk are now considered as such



The funny thing is, when i looked at the title of this thread,
i went, "WOW, Andromeda is about 750,000 light years
across???"

We already *knew* Andromeda was about 220,000 ly
in diameter (which is actually 30,000 ly LESS than the old
SEDS figure). So what's the big fuss???

Hmm, see what you mean, tricky, and interesting, I have no idea ;-)
but would like to know.



happy days and...
starry starry nights!

--
Space so scary, quite contrary,
How does your nothing grow?
A just as hairy corollary...
What makes your nothing flow?

Indelibly yours,
Paine http://www.savethechildren.org/