Does the sun move ?

[Dinesh_college]

Our Earth is rotating the sun along with Moon.

 

Similarly does the sun rotates around something else?

Or it is stable?

[pgrmdave]

The sun moves through the galaxy, and rotates around the center of galaxy, although it takes a very long time for it to do so.

[Tormod]

Additionally, the Sun orbits the combined center of mass of the solar system.

 

The Earth actually pulls at the Sun. This pull, however, is so small that the common center of mass in the Sun-Earth system lies close the the centre of the Sun. All of the planets tug at the Sun in this way, making the Sun wobble slightly. This is one way planets around distant stars are detected.

[Boerseun]

...and then, to make matters worse, the galaxy is orbiting the center of mass of a whole host of other galaxies, which in turns orbits the center of mass of a whole Supergroup of galaxies which in turns orbits... you get the picture, I'm sure.

 

You are now, as you sit behind your monitor, blasting away at one heck of a speed. Towards... uhm... somewhere. But it's hundreds of thousands of kilometers per hour.

[infamous]

...and then, to make matters worse, the galaxy is orbiting the center of mass of a whole host of other galaxies, which in turns orbits the center of mass of a whole Supergroup of galaxies which in turns orbits... you get the picture, I'm sure.

 

You are now, as you sit behind your monitor, blasting away at one heck of a speed. Towards... uhm... somewhere. But it's hundreds of thousands of kilometers per hour.

Absolutely Boerseun, and because there can be no absolute frame of reference, our velocity can even be much greater.

[Qfwfq]

Absolutely Boerseun, and because there can be no absolute frame of reference,

our velocity can even be whatever you like, between zero and almost c, in whichever direction you like! :hihi:

[nkt]

And don't forget that the sun itself rotates on its axis.

 

Once the solar system gets to the great mating ground, the question of which sex the turtle carrying the earth on its back will be pretty majorly important... how come no-one ever talks about it? :hihi:

[Tormod]

how come no-one ever talks about it? :hihi:

 

Because it's a gang-bang, with turtles all the way down! :hihi:

[C1ay]

Our Earth is rotating the sun along with Moon.

 

Similarly does the sun rotates around something else?

Or it is stable?

Like maybe another star? Take a glance at the Binary Research Institute where they think our star is part of a binary star system. I think their ideas are thought provoking.

[Qfwfq]

With which other star? Alpha centauri?

 

I really don't think it would have so far escaped notice.

[alxian]

it is said the sun may have a companion [brown dwarf] somewhere in the kuiper belt

 

jupiter could also have been a companion star had it amassed enough stellar dust and debris to ignite and become a star a la 2001.

[Qfwfq]

a la 2001.

Wasn't that 2010?

[Tormod]

Wasn't that 2010?

 

Yup. Thank heavens they didn't film 2061...

[nkt]

That binary star idea is one I've heard before, but thought was rubbish. However, I've just read through their website, and it is suprisingly sane, and very well funded. It is also plausible.

 

I've not done any of the maths nor checked the data they quote, but I can see that if you had a dwarf orbiting in the order of 8000 years+, human observation would have missed it if it was now far away. After all, we have only had telescopes for a few hundred years, and eye observations would have missed a not-bright object.

 

I do think, however, that IR observation would have found it. But has anyone looked? There is a heck of a lot of sky out there.

 

Any thoughts?

[Qfwfq]

Any thoughts?

Well, I must say, the brown dwarf hypothesis isn't impossible.

 

It took a good while to find the tenth planet. If it has a compareable mass to the Sun, surely parallax could help to estimate where to look. I haven't read much about it.

[nkt]

I've always wanted to get a telescope for astronomical use, but have never managed to justify it to myself. However, a 6" or 8" reflector isn't going to pick up something that dark unless it moves across something behind whilst you are looking at it. Even then, it is likely to be marginal.

 

Better calculations of the precise position would be useful, and shouldn't be too hard to mock-up in a computer simulation. How precise it could be is another matter, however.

 

Now if I could just build that starship in the garage, we could know for sure.

[Qfwfq]

Now if I could just build that starship in the garage, we could know for sure.

How sure?

 

A starship isn't enough. What you need is to make precise parallax measurements over a significant time compared with the pair's orbital period.