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Stars of Constellations exist in what Spiral Arm of the Milky Way Galaxy?

by Philosophaie
Tags: constellations, exist, galaxy, milky, spiral, stars
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Philosophaie
#1
Nov26-12, 02:44 PM
P: 371
The Milky Way is a Barred Spiral Galaxy 100,00 -120,000 Across.

I was wondering if there is a website or list of what Stars of Constellations exist in what Spiral Arm.

I there exists:
Orion-Cygnus Arm
Perseus Arm
Scutum-Centaurus Arm
Norma and Outer Arm
Carina-Sagitarius Arm

http://en.wikipedia.org/wiki/Milky_way gives some of the stars in the constellations without locations.

Is the a more comprehensive list?
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mathman
#2
Nov26-12, 03:30 PM
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My guess: The stars in the constellations are all in the same arm as the sun. I suspect stars in other arms would not be observable individually.
Vanadium 50
#3
Nov26-12, 09:55 PM
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Virtually every naked-eye star is in the Orion arm. Eta Leonis is an exception, but these are rare.

Bandersnatch
#4
Nov27-12, 06:35 AM
P: 740
Stars of Constellations exist in what Spiral Arm of the Milky Way Galaxy?

Quote Quote by Vanadium 50 View Post
Eta Leonis is an exception, but these are rare.
Are you sure about this?
It's ~1200ly away(http://simbad.u-strasbg.fr/simbad/sim-id?Ident=HD+87737), and according to this (http://messier.seds.org/more/mw_arms.html) list of objects associated with each arm, it'd have to be some ~4kly away to be considered as lying in another arm.
age123
#5
Nov27-12, 06:53 AM
P: 10
Have many people reported observing a super nova in real time. And if so, could you observe such an event with the naked eye, or could you only observe it with a high powered telescope!
age123
#6
Nov27-12, 06:58 AM
P: 10
Have many people have reported observing a super nova in real time. And if so, could you observe such an event with the naked eye, or would you require a high powered telescope? And if you did observe a super nova, with the naked eye, would of it occurred in the Milky Way galaxy, or another galaxy!
mfb
#7
Nov27-12, 09:28 AM
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You can observe a supernova in other arms with the naked eye, if there is one, and if there is not too much gas in the line of sight. No supernova in our galaxy was observed since 1604, however.
age123
#8
Nov27-12, 04:08 PM
P: 10
Interesting. I live in the Southern Hemisphere and I think I may of witnessed a type m super nova about 15 years ago. Has there been any reports of stars going missing around 1996-97. I have been thinking a lot about what I observed that year. And the only thing which seems to fit with what I observed is the current theory surrounding the events of a type m super nova! Other people have been helpful, but feel that I maybe witnessed a meteor shower or perhaps imagined it. Thankyou.
mfb
#9
Nov28-12, 05:08 AM
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A supernova would appear like a (very) bright star over hours or days, unlike a meteor shower.
phyzguy
#10
Nov28-12, 01:16 PM
P: 2,195
Quote Quote by age123 View Post
Have many people reported observing a super nova in real time. And if so, could you observe such an event with the naked eye, or could you only observe it with a high powered telescope!
Supernova 1987A, which occurred in the Large Magellanic Cloud (a satellite galaxy that orbits the Milky Way) was visible to the naked eye. It peaked at about visual magnitude +3, which is a medium bright star. I'm waiting for Betelgeuse to go supernova - it could be as bright as the full moon!
russ_watters
#11
Nov28-12, 04:01 PM
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Quote Quote by age123 View Post
Interesting. I live in the Southern Hemisphere and I think I may of witnessed a type m super nova about 15 years ago. Has there been any reports of stars going missing around 1996-97. I have been thinking a lot about what I observed that year. And the only thing which seems to fit with what I observed is the current theory surrounding the events of a type m super nova! Other people have been helpful, but feel that I maybe witnessed a meteor shower or perhaps imagined it. Thankyou.
What exactly did you see? A very naked-eye supernova that nobody else saw would be pretty much impossible 15 years ago.

Today, so many astrophotographers are taking pictures that a supernova in any of the nearest few hundred galaxies would be noticed by several, independently.
Bandersnatch
#12
Nov28-12, 06:07 PM
P: 740
(S)He described the memory of the event here:
http://www.physicsforums.com/showthr...73#post4174973
age123
#13
Dec6-12, 01:07 AM
P: 10
The event I witnessed was very different to a star shinning really brightly. It envolved two stars, that were position very close together. One in particular was flickering dull then bright on and off for about 10 seconds. Then the other one appeared to shoot at the other one, about 4-5 times. Then the star that did all the shooting exploded along the trajectory of the particles that it fired off and engulfed the entire star. It's quite difficult to explain. What do you think it was? I looked up a type m supernova, and the way it is described sounds very similar to what I witnessed.
mfb
#14
Dec6-12, 04:01 AM
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Quote Quote by age123 View Post
I looked up a type m supernova, and the way it is described sounds very similar to what I witnessed.
You cannot see binary stars as separate objects without a telescope, that is way beyond the physical limit of an eye. In addition, the timescale would be wrong.

Maybe you saw some airplane-related effects, or an optical illusion in some way. But not variable stars.
glappkaeft
#15
Dec6-12, 05:40 AM
P: 84
Quote Quote by mfb View Post
You cannot see binary stars as separate objects without a telescope, that is way beyond the physical limit of an eye.
While I agree with your other points this couldn't be more wrong. You don't even need a telescope to split double stars. For instance the naked eye is enough to split the two main components of the quadruple system Mizar and Alcor in the Big Dipper's handle. With a small telescope you can split thousands of double stars.
Bandersnatch
#16
Dec6-12, 07:14 AM
P: 740
Quote Quote by glappkaeft View Post
While I agree with your other points this couldn't be more wrong. You don't even need a telescope to split double stars. For instance the naked eye is enough to split the two main components of the quadruple system Mizar and Alcor in the Big Dipper's handle. With a small telescope you can split thousands of double stars.
I admit that I'm not up to date with recent astronomy, but last time I checked, at over one light year apart, Alkor and Mizar form a binary in the same sense(and with similar certainty) that Alpha and Proxima Centauri do.

Still, we can use that example to show age123 why he coudn't possibly see a supernova acting like he saw.

Alkor and Mizar are ~80ly away, and ~1ly apart. They are separated by a 4arcminutes angle on the sky. This is some 3 times under the limit of human eye resolution(1.2 arcmin).
So, at that distance, it is in principle possible to separate two stars orbiting each other at 1/3rd of a light year.
This in turn, is some 10000 times farther than the orbital radius of binary stars that undergo the Ia supernova event age123 is alluding to.
Even if we imagined some mass transfer between the two stars at such a distance, it'd take a larger part of a year, not a few seconds. Otherwise the mass would have to travel faster than light.
Additionally, if a supernova exploded 80ly away from Earth, we'd all be dead, most likely.

But let's say the supernova is ~800ly away, at which distance we'd be pretty safe (although it would be close enough to have a good chance to outshine the Moon), and the binary elements are 6AU apart.
The angular separation between the binary components would now be 4arcmin/105 ≈ 0.00024 arcsec
or roughly thirty thousand times beyond human eye resolution capabilities.

Seeing the binary components of a Ia supernova with a naked eye would be similarly impossible as seeing the fine structure of DNA.

So, if somebody told you that they saw something vaguelly like a double helix in their cup of coffee, you would be just as sure as we are that whatever it was, it wasn't DNA.
mfb
#17
Dec6-12, 10:23 AM
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Quote Quote by glappkaeft View Post
While I agree with your other points this couldn't be more wrong. You don't even need a telescope to split double stars. For instance the naked eye is enough to split the two main components of the quadruple system Mizar and Alcor in the Big Dipper's handle. With a small telescope you can split thousands of double stars.
Ok, I should have been more specific at "binary stars". There are systems which are gravitationally bound and can be resolved by the naked eye. But gravitationally bound is not the point. If stars are so close that they interact with each other in a significant way (with mass flow, tidal forces or similar effects), you cannot resolve that system with the naked eye.
glappkaeft
#18
Dec6-12, 04:02 PM
P: 84
Quote Quote by mfb View Post
Ok, I should have been more specific at "binary stars". There are systems which are gravitationally bound and can be resolved by the naked eye. But gravitationally bound is not the point. If stars are so close that they interact with each other in a significant way (with mass flow, tidal forces or similar effects), you cannot resolve that system with the naked eye.
Definitely. Or if you could separate them they would be way too close for comfort...


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