Magnesium and silicon in a pair of colliding galaxies

NASA's Chandra X-ray Observatory has discovered rich deposits of magnesium
and silicon in a pair of colliding galaxies known as The Antennae. The
deposits are located in vast clouds of hot gas, and when the clouds cool,
say scientists, a great number of stars and planets should form. These
results may foreshadow the fate of our own Milky Way and its future
collision with the Andromeda Galaxy.

FULL STORY at

http://science.nasa.gov/headlines/y2...htm?list768530

Bruce Scott wrote:

They note our galaxy is on a collision course with M31 (Andromeda).
Don't worry... the time scale is 3 Gyr :-)

I wish these guys would quit saying this as if it were a fact. Although the
radial velocity of M31 is towards us, we have absolutely no idea what the
transverse velocity (proper motion) is, so M31 could just as easily either
pass us with merely a glancing blow in the far future or miss hitting our
galaxy completely with plenty of room to spare. It will take probably a
couple of centuries before we can accurately measure any transverse motion in
M31 optically, so the statement that our galaxy and M31 are really going to
collide is more than a little premature!

Question to the amateurs: how visible is this in small scopes?
(Mine is a 10 cm Meade SC)

Well, I don't quite know what "small" is anymore, but the galaxy in question
is NGC 4038-9 (a.k.a. "the Ringtail Galaxy"), a 10th magnitude interacting
spiral in western Corvus about 3.6 degrees southwest of Gienah (Gamma Crv).
It is visible in a 4 inch under really good conditions, but seeing its
"ring-tail" form requires something a bit larger, like an 8 or 10 inch. In
moderate to large apertures at moderate power, it looks like an oval puff with
a bit of a "hook" off the southeast side. In my ten inch Newtonian at 178x,
the main galaxy (NGC 4038) shows a patchy oval ring-like form in the hazy
glow, while the other galaxy (NGC 4039) appears mostly as a diffuse flowing
extension off the east end of the main galaxy which hooks to the south. Some
people have said that this object looks like a shrimp, and that is not far
from the truth!
The very faint outer tidal tails (the "antennae") of this object are not
usually visible in most amateur telescopes, although they can be imaged fairly
easily by a long exposure using a moderate aperture and a good CCD setup.
This object is on the Herschel 400 listing, so if you ever do that observing
project, you will run into it. 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 *
**********************************************

Bruce Scott wrote:

They note our galaxy is on a collision course with M31 (Andromeda).
Don't worry... the time scale is 3 Gyr :-)

I wish these guys would quit saying this as if it were a fact. Although the
radial velocity of M31 is towards us, we have absolutely no idea what the
transverse velocity (proper motion) is, so M31 could just as easily either
pass us with merely a glancing blow in the far future or miss hitting our
galaxy completely with plenty of room to spare. It will take probably a
couple of centuries before we can accurately measure any transverse motion in
M31 optically, so the statement that our galaxy and M31 are really going to
collide is more than a little premature!

Question to the amateurs: how visible is this in small scopes?
(Mine is a 10 cm Meade SC)

Well, I don't quite know what "small" is anymore, but the galaxy in question
is NGC 4038-9 (a.k.a. "the Ringtail Galaxy"), a 10th magnitude interacting
spiral in western Corvus about 3.6 degrees southwest of Gienah (Gamma Crv).
It is visible in a 4 inch under really good conditions, but seeing its
"ring-tail" form requires something a bit larger, like an 8 or 10 inch. In
moderate to large apertures at moderate power, it looks like an oval puff with
a bit of a "hook" off the southeast side. In my ten inch Newtonian at 178x,
the main galaxy (NGC 4038) shows a patchy oval ring-like form in the hazy
glow, while the other galaxy (NGC 4039) appears mostly as a diffuse flowing
extension off the east end of the main galaxy which hooks to the south. Some
people have said that this object looks like a shrimp, and that is not far
from the truth!
The very faint outer tidal tails (the "antennae") of this object are not
usually visible in most amateur telescopes, although they can be imaged fairly
easily by a long exposure using a moderate aperture and a good CCD setup.
This object is on the Herschel 400 listing, so if you ever do that observing
project, you will run into it. 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 *
**********************************************

Bruce Scott wrote:

They note our galaxy is on a collision course with M31 (Andromeda).
Don't worry... the time scale is 3 Gyr :-)

I wish these guys would quit saying this as if it were a fact. Although the
radial velocity of M31 is towards us, we have absolutely no idea what the
transverse velocity (proper motion) is, so M31 could just as easily either
pass us with merely a glancing blow in the far future or miss hitting our
galaxy completely with plenty of room to spare. It will take probably a
couple of centuries before we can accurately measure any transverse motion in
M31 optically, so the statement that our galaxy and M31 are really going to
collide is more than a little premature!

Question to the amateurs: how visible is this in small scopes?
(Mine is a 10 cm Meade SC)

Well, I don't quite know what "small" is anymore, but the galaxy in question
is NGC 4038-9 (a.k.a. "the Ringtail Galaxy"), a 10th magnitude interacting
spiral in western Corvus about 3.6 degrees southwest of Gienah (Gamma Crv).
It is visible in a 4 inch under really good conditions, but seeing its
"ring-tail" form requires something a bit larger, like an 8 or 10 inch. In
moderate to large apertures at moderate power, it looks like an oval puff with
a bit of a "hook" off the southeast side. In my ten inch Newtonian at 178x,
the main galaxy (NGC 4038) shows a patchy oval ring-like form in the hazy
glow, while the other galaxy (NGC 4039) appears mostly as a diffuse flowing
extension off the east end of the main galaxy which hooks to the south. Some
people have said that this object looks like a shrimp, and that is not far
from the truth!
The very faint outer tidal tails (the "antennae") of this object are not
usually visible in most amateur telescopes, although they can be imaged fairly
easily by a long exposure using a moderate aperture and a good CCD setup.
This object is on the Herschel 400 listing, so if you ever do that observing
project, you will run into it. 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 *
**********************************************

Sam Wormley wrote in
:

our own Milky Way and its future collision with the Andromeda Galaxy.

Our galaxy is a lot larger than the Andromeda galaxy, and I expect that we
will simply absorb Andromeda, as we are absorbing the dwarf Sagittarius
galaxy right now. I'm sure it will disrupt our structure somewhat, but I
believe that the Milky Way will stabilize after that. We seem to be large
enough to be the galaxy that does the absorbing, rather than the one that
is being absorbed.

Sam Wormley wrote in
:

our own Milky Way and its future collision with the Andromeda Galaxy.

Our galaxy is a lot larger than the Andromeda galaxy, and I expect that we
will simply absorb Andromeda, as we are absorbing the dwarf Sagittarius
galaxy right now. I'm sure it will disrupt our structure somewhat, but I
believe that the Milky Way will stabilize after that. We seem to be large
enough to be the galaxy that does the absorbing, rather than the one that
is being absorbed.

Sam Wormley wrote in
:

our own Milky Way and its future collision with the Andromeda Galaxy.

Our galaxy is a lot larger than the Andromeda galaxy, and I expect that we
will simply absorb Andromeda, as we are absorbing the dwarf Sagittarius
galaxy right now. I'm sure it will disrupt our structure somewhat, but I
believe that the Milky Way will stabilize after that. We seem to be large
enough to be the galaxy that does the absorbing, rather than the one that
is being absorbed.

To my understanding it's the other way around: Andromeda is larger than the
Milky Way.
Glenn Thureson

"John Schutkeker" wrote in message
4...
Sam Wormley wrote in
:

our own Milky Way and its future collision with the Andromeda Galaxy.

Our galaxy is a lot larger than the Andromeda galaxy, and I expect that we
will simply absorb Andromeda, as we are absorbing the dwarf Sagittarius
galaxy right now. I'm sure it will disrupt our structure somewhat, but I
believe that the Milky Way will stabilize after that. We seem to be large
enough to be the galaxy that does the absorbing, rather than the one that
is being absorbed.

To my understanding it's the other way around: Andromeda is larger than the
Milky Way.
Glenn Thureson

"John Schutkeker" wrote in message
4...
Sam Wormley wrote in
:

our own Milky Way and its future collision with the Andromeda Galaxy.

Our galaxy is a lot larger than the Andromeda galaxy, and I expect that we
will simply absorb Andromeda, as we are absorbing the dwarf Sagittarius
galaxy right now. I'm sure it will disrupt our structure somewhat, but I
believe that the Milky Way will stabilize after that. We seem to be large
enough to be the galaxy that does the absorbing, rather than the one that
is being absorbed.

To my understanding it's the other way around: Andromeda is larger than the
Milky Way.
Glenn Thureson

"John Schutkeker" wrote in message
4...
Sam Wormley wrote in
:

our own Milky Way and its future collision with the Andromeda Galaxy.

Our galaxy is a lot larger than the Andromeda galaxy, and I expect that we
will simply absorb Andromeda, as we are absorbing the dwarf Sagittarius
galaxy right now. I'm sure it will disrupt our structure somewhat, but I
believe that the Milky Way will stabilize after that. We seem to be large
enough to be the galaxy that does the absorbing, rather than the one that
is being absorbed.