'First ever' snap emerges of something vaguely resembling our solar system 300 ly away. We'll take 10 tickets Astronomers say they have snapped a multi-planetary system containing a Sun-like star for the first time. Hundreds of stars harboring two or more orbiting exoplanets have been discovered, though taking decent photos of these systems is difficult. The brightness of the star normally drowns everything else, and less than one per …
The inner planet is 160AU and the outer 320AU???
For comparison, Jupiter is only 5AU from the Sun, Neptune is 30AU, Pluto at its furthest is only 49AU, heck the Heliopause kicks in at 123AU.
And this young Sun has two gas giants in its system massively beyond its Heliopause? There's not perhaps been an extra 0 mistakenly added on the end of those numbers, perhaps?
If those numbers are right, then just wow. I mean the Sun does manage to "hold" on to (for a given definition of hold) the Oort cloud which supposedly stretches beyond 100000 AU, but thats just small comets.
Gas Giants at 160 and 320AU must have only a relatively tentative grasp of their Suns gravity. I imagine it wouldnt take too much in the way of collisions or close encounters with other planetary bodies to send them hurtling away from their parent system.
The Universe never ceases to be amazing, does it?
Don't forget that the force due to gravity is a function of the masses of both objects, so the attraction of Gas Giants to their sun would be greater than that of small comets (assuming a giant has a giant mass, despite being gas), even at that great distance.
After all, galaxies manage to attract each other too at relatively vast distances. Gravity goes on forever, in theory.
My first reaction was that "very similar to our Solar System" relies on your definition of "very similar". But he goes on to say "but at a much earlier stage of its evolution". Does this mean that the early Solar System is considered to have been similarly widely spaced?
I don't know about what people think the orbits were like in the early Solar system, but I can't see how things would manage to lose that much energy to change orbit that much.
However I think the 'very similar to the Solar system' really means 'the star is like a young version of the Sun', not that the planets are similar to ours. However the ESO press release does say 'This discovery is a snapshot of an environment that is very similar to our Solar System, but at a much earlier stage of its evolution', so I'm not sure.
It's our solar system all the way until the suns gravity well is matched by the next star, Alpha Centauri, this being only a slightly bigger mass puts the solar system currently at a little over four light years across (roughly 250k AU).
For our system, A 6x-14x Jupiter mass orbiting only a degree off plane 160+AU out may take decades to deduce from the tiny effect it would have on anything we can see accurately at the moment*.
Just to stir the Pluto pot, as they're very new and most likely haven't cleared their orbital path yet these monsters would not be classed as 'planets' in our solar system.
* We have only observed one full orbit of Neptune (165 yrs) & less than half of Plutos (248 yrs).
Unless you live in Scotland where they have no such power. It is perfectly legal to declare you have no capable receiving equipment. There’s a very hard to find form on the BBC website you fill in. I did it and a nice young man rang me to check. When told my reasons were Scottish political (I object to being taxed to be lied and propaganded to) he was not in the least bit surprised.
Aunty will not release figures for how many folk up here have cancelled their TV licenses claiming (ha, ha) that they don’t collect country by country figures. But twitter and facebook are awash with folk saying they have done it and the website in question can easily be found along with instructions on how to fill it in.
You can still watch subscription only services such as Netflix, Prime etc but you can’t use a smart TV to it since they can get signals. So you will have to buy a nice big dumb computer screen if you want the family to watch together on one screen.
But when I see the time-lapse of the heavens wheeling above and around the observatory, and think of how small we hominins are, and yet we can look into that starry vastness and both measure and understand, from the most attenuated information the forms, distances and masses of systems, I stand amazed. The wonder of intelligence, curiosity, and science is breathtaking. What a privilege to live in this time.
At the moment we can only detect things that are fairly massive going around close or very massive going around further away, so of course that is what we will find.
Solar systems like ours may be among the commonest in the Universe for our star type, but at the moment we've got no way of detecting them. This is not to knock exoplanet research, though. It's really quite astonishing that finding planets around other stars is now almost routine.
As for the explanation of the sizes and masses, it's well known that younger stars, like younger people, like to throw their weight around and look big.
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