Where are we?

[parallaxicality]

Our solar system is in the Milky Way galaxy, which is part of a local group of galaxies in orbit about each other. It consists of a star that has planets in orbit around it. Does the same apply to stars? Does the Solar System have any stars to which it is gravitationally linked?

[Noclevername]

Not linked, no. We're not close enough.

[parallaxicality]

So could there be said to be such a thing as the local solar neighborhood?

[AndreasJ]

So could there be said to be such a thing as the local solar neighborhood?
The phrase "solar neighbourhood" usually means "the space close enough to the Sun for present purposes", which exists because else we wouldn't be considering it. For a meaningful answer, you'll have to specify what you mean by a "local solar neighborhood". :)

[parallaxicality]

Alright. Can there, in any way, be said to be a local group of stars, in the same way that there is a local group of galaxies?

[AndreasJ]

No, nothing analoguous to the local group on the stellar level. Some stars move around the galaxy in coherent clusters, orbiting the cluster's common centre of mass as that orbits the galaxy's, but the Sun goes round the galaxy independently, and its present neighbours will drift away on galactically speaking short timescales.

[Kullat Nunu]

Our solar system is in the Milky Way galaxy, which is part of a local group of galaxies in orbit about each other. It consists of a star that has planets in orbit around it. Does the same apply to stars? Does the Solar System have any stars to which it is gravitationally linked?

Well, since gravity field is theoretically infinite and it propagates at the speed of light, the Sun affects gravitationally any star that is close enough that light from the Sun has reached it. That makes great many millions on of billions of stars in total. ;) On the other hand, the gravitational effect the Sun causes on even the closest stars is extremely tiny because stellar distances are so huge. You can calculate it by yourself and compare to the force binary stars cause to each other. As you can see, binary stars are not stable if their distances are light years (intergalactic space aside).

[grant hutchison]

The sun was presumably "born" in gravitational linkage with other stars in its stellar nursery. But these clusters tend to evaporate over time, both because of gravitational interactions between the members, and because a large mass of residual gas and dust is blown off when the stars first light up within the parent molecular cloud: this loss of mass gravitationally "unbinds" the cluster.
So, AFAIK, the other members of the Sun's natal family are long since dispersed around the galaxy.

Grant Hutchison

[01101001]

I think I've mentioned an article a couple of times before in other threads. I like the animation (http://www.space.com/php/multimedia/imagedisplay/img_display.php?pic=040406_milkyway_anim_02.gif&cap=Sun%27s+last+250-million-year+orbit+around+the+center+of+the+galaxy.+BAUT Forum rulez.+Credit%3A+ESO) showing how the widely spread-out bunch of stars came to be the current close neighbors over the sun's last Milky Way orbit.

Space.com: The Crazy Cosmos: Stars Near Sun are Wild & Wayward (http://www.space.com/scienceastronomy/milkyway_movement_040406.html)


European astronomers spent 15 years making 1001 nights of observations to detail the motions of more than 14,000 stars that are currently in the solar neighborhood, a tiny corner of the Milky Way. Tracing the movements back in time with a computer, the researchers found that most of the stars were once much farther from the Sun than they are today.

[Noclevername]

Stars just don't have enough gravity individually to hold to each other unless they're very close. But galaxies, with the collective mass of billions of stars, can hang on to each other over millions of light-years.