How long does it take our solar system to orbit the galaxy?

[bolloman]

This may be a simple question for some.<br /><br />I'm going to guess about 3 billion years based on other orbit/diameter ratios....assuming our solar system is about 45,000 light years from the center of our galaxy. I'm not sure my assumptions are correct.<br /><br />Does anyone have a more accurate answer?

 

[Saiph]

actually, I think its about 200 to 250 million years. <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>

 

[vogon13]

Close enough.<br /><br />Tired of the view here?, Just wait.<br /><br /><img src="/images/icons/wink.gif" /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[Saiph]

that, and it isn't a simple proportion. <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>

 

[spaceinvador_old]

But as we orbit our galaxy, doesn't our inner our outer position change? Are we getting closer to the center or further?

 

[nexium]

The peculiar thing is orbital speed decreases for stars closer to the galactic hub and the ourskirts of our galaxy are orbiting about twice our speed. If r = 60,000 light years; C = 6.28 times 60,000 light years = 377,000 light years in 200,000,000 years: 1.88 light years per thousand years. Two or three light years per thousand years, due to the up down motion. The naked eye scene does not change much as nearby stars are orbiting close to the same speed and direction.<br />If near the hub orbits that fast, the galaxy winds up so tight, the spiral arms disappear in about two turns. Neil

 

[newtonian]

nexium - Yes, galactic rotation is peculiar - in fact, most astronomers take the rotational properties as proof of the existence of dark matter.<br /><br />One would expect star velocities to decrease beyond our sun's distance from the galactic core. Actually, those velocities increase - from about 230 km/sec for our sun [at about 28,000 light years from galactic core] to about 300km/sec at a radius of 60,000 light years.<br /><br />Those numbers are found in "The World of Science," 1991, by Andromeda Oxford Ltd. [distributed by Britannica], Volume 8, pp. 68,69.<br /><br />The latter source states it takes about 220 million years for our sun to orbit the core.<br /><br />It also estimates Milky Way mass to be between 1 trillion and 2 trillion solar masses - much greater than what can be observed - hence indicating much dark matter.<br /><br />We are very interested in solving that scientic question, as the following quote exemplifies:<br /><br />"The Andromeda galaxy, like all spiral galaxies, rotates majestically in space as if it were a giant hurricane. Astronomers can calculate the rate of rotation for many galaxies from the light spectra, and when they do, they discover something puzzling. The rotation rates seem to be impossible! All spiral galaxies seem to rotate too fast. They behave as if the visible stars of the galaxy were embedded in a much larger halo of dark matter, invisible to the telescope. “We do not know the forms of the dark matter,” admits astronomer James Kaler. Cosmologists estimate that 90 percent of the missing mass is unaccounted for. They are frantic to find it, either in the form of massive neutrinos or some unknown but superabundant type of matter." - "Awake!," 1/22/96, p. 14.<br /><br />

 

[vogon13]

Look at a good picture of the Great Galaxy in Andromeda. Are there one or two spiral arms?<br /><br />Weird, huh?<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[newtonian]

vogon13 - Could be one arm circlling more than once?<br /><br />Can you link to a good photo - like, for example, a Hubble photo?

 

[vogon13]

One arm circling more than once is one arm. <img src="/images/icons/wink.gif" /><br /><br />My internet skills are sufficient to knock out service globally should I ever try to load a picture. There is probably a good one here somewhere, and hopefully someone will happen by and tell us where it is.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[newtonian]

vogon13 - Here's an SDC link for Andromeda photos:<br /><br />http://www.space.com/bestimg/index.php?guid=4295f2d41fe2e&cat=galactic

 

[pyoko]

Is it spinning at all? It looks like a spinny thing, but it is spinning relative to what? A stationary point, but stationary relative to what? Sorry if this is a foolish question. <div class="Discussion_UserSignature"> <p> </p><p> </p><p><span style="color:#ff9900" class="Apple-style-span">-pyoko</span> <span style="color:#333333" class="Apple-style-span">the</span> <span style="color:#339966" class="Apple-style-span">duck </span></p><p><span style="color:#339966" class="Apple-style-span"><span style="color:#808080;font-style:italic" class="Apple-style-span">It is by will alone I set my mind in motion.</span></span></p> </div>

 

[spaceinvador_old]

I think everything is moving. The earth goes around the sun. The sun goes around another object and so on... We are constantly moving, since we are affixed to this planet which is also moving. Everything is in some kind of motion. Movement=time

 

[pyoko]

It is spinning around the center. How did we measure this spin around the supposed supermassive black hole and the dark matter? <div class="Discussion_UserSignature"> <p> </p><p> </p><p><span style="color:#ff9900" class="Apple-style-span">-pyoko</span> <span style="color:#333333" class="Apple-style-span">the</span> <span style="color:#339966" class="Apple-style-span">duck </span></p><p><span style="color:#339966" class="Apple-style-span"><span style="color:#808080;font-style:italic" class="Apple-style-span">It is by will alone I set my mind in motion.</span></span></p> </div>

 

[Saiph]

we measure it by observing how other stars move around us, and how stars move around the core of the galaxy.<br /><br />Then, we compare those to keplars and newtons laws, to see what is required to make things move that way. <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>

 

[jatslo]

This is not a simple question, but an important question. I would be curious to know if our solar system is receding from the center of our galaxy, or if it is getting drawn into it. It is doubtful that we are on an equilibrium plain.

 

[vogon13]

Eccentricity of the sun's orbit about the galaxy is not known precisely, but a large value would be evident in the stellar kinematics statistics. A large value (IMO) would be e=0.1. <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[vogon13]

Thanx! <br /><br />{almost missed that}<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[jatslo]

<blockquote><font class="small">In reply to:</font><hr /><p>If the universe appears to be accelerating then we could be receding or losing velocity relative to the universe, and we should be able to use similar measurements to extrapolate this speculation.<blockquote><font class="small">In reply to:</font><hr /><p>Eccentricity of the sun's orbit about the galaxy is not known precisely, but a large value would be evident in the stellar kinematics statistics. A large value (IMO) would be e=0.1.<p><hr /></p></p></blockquote><p><hr /></p></p></blockquote>

 

[pyoko]

We are all getting sucked into the supermassive black hole in the center of the Milky Way! The Milky Bars are on me!!!! (jk) <div class="Discussion_UserSignature"> <p> </p><p> </p><p><span style="color:#ff9900" class="Apple-style-span">-pyoko</span> <span style="color:#333333" class="Apple-style-span">the</span> <span style="color:#339966" class="Apple-style-span">duck </span></p><p><span style="color:#339966" class="Apple-style-span"><span style="color:#808080;font-style:italic" class="Apple-style-span">It is by will alone I set my mind in motion.</span></span></p> </div>