Astronomers Find the Farthest-Out Solar System Object Ever Seen!

Nothing to get excited about?

Maybe that dude is in the wrong business. I am not an astronomer and I think it's pretty cool.

Makes you wonder what else is 'really' out there versus what's 'expected' to be out there

originally posted by: ABNARTY
Nothing to get excited about?

Maybe that dude is in the wrong business. I am not an astronomer and I think it's pretty cool.

Makes you wonder what else is 'really' out there versus what's 'expected' to be out there

I concur. I think it's pretty exciting!

Already discussed here: www.abovetopsecret.com...

At least take a look at the first page of the forum before making a thread.

And In my hand I hold a card nicknamed the joker

a reply to: ABNARTY
As viewing and imagery equipment improve, it'll be exciting to see what else is out there beyond the galaxies!

originally posted by: CranialSponge
a reply to: Cosmic911

Interesting !

It's things like this that get me wondering just how far do the gravitational tentacles of our solar system reach out into the galaxy ?

It actually extends for as far as the Universe does. It just gets really weak.

originally posted by: OccamsRazor04

originally posted by: CranialSponge
a reply to: Cosmic911

Interesting !

It's things like this that get me wondering just how far do the gravitational tentacles of our solar system reach out into the galaxy ?

It actually extends for as far as the Universe does. It just gets really weak.

Yes, but in practical terms, every object's (or a system of objects') gravity eventually ceases to be relevant out to a certain distance where the gravity from other objects or systems becomes more prevalent. I think what Cosmic911 meant is the Solar System's sphere of gravitational influence. Such a region of space around any source of gravity is called the Hill sphere.

One simple view of the extent of the Solar System is the Hill sphere of the Sun with respect to local stars and the galactic nucleus: adsabs.harvard.edu... This linked paper gives the radius of the Sun's Hill sphere (with respect to the galactic core) as 230,000 AU which is approximately 3.6 light years. This is more than half-way to the nearest star system Alpha Centauri, which is approx twice as massive as the Sun, so the effective radius of the Sun's Hill sphere would be much smaller (perhaps out to 2 light years?)

a reply to: wildespace

Far more eloquently explained.

And come on! Over the weekend, and especially on Sundays, this forum literally grinds to a hault. I visit it and grow sad at the lack of posts or replies.

Get posting, people! Don't let the weekend hold you! m/

originally posted by: wildespace

originally posted by: OccamsRazor04

originally posted by: CranialSponge
a reply to: Cosmic911

Interesting !

It's things like this that get me wondering just how far do the gravitational tentacles of our solar system reach out into the galaxy ?

It actually extends for as far as the Universe does. It just gets really weak.

Yes, but in practical terms, every object's (or a system of objects') gravity eventually ceases to be relevant out to a certain distance where the gravity from other objects or systems becomes more prevalent. I think what Cosmic911 meant is the Solar System's sphere of gravitational influence. Such a region of space around any source of gravity is called the Hill sphere.

One simple view of the extent of the Solar System is the Hill sphere of the Sun with respect to local stars and the galactic nucleus: adsabs.harvard.edu... This linked paper gives the radius of the Sun's Hill sphere (with respect to the galactic core) as 230,000 AU which is approximately 3.6 light years. This is more than half-way to the nearest star system Alpha Centauri, which is approx twice as massive as the Sun, so the effective radius of the Sun's Hill sphere would be much smaller (perhaps out to 2 light years?)

My brain literally spun on it's axis reading your post! I am going to look up Hill Sphere. I am less than an amateur astronomer, understanding very little about the cosmos, though I am learning and soaking up what I can. Yes, you are correct in that I was asking about the gravitational forces created by our solar system.

Off note...I think it's incredibly boring that our moon is called The Moon and our sun is called The Sun. So generic, though I'm sure at the time they were named we could not have imagined there might be other suns and moons in the Universe, because, of course, Earth was the center of everything.

a reply to: stormcell

The limit to the gravitational influence of the sun is where the sun's gravity becomes as small as the random galactic gravity fluctuations. The galaxy has a gravitational field, as the sun does, but it is more irregular because instead of one ball of plasma, the galaxy is an irregular disk-shaped thing, with lots of blobs flying around in 3d, giant clouds and much more. So there are real irregularities in the gravitational force of the galaxy. The sun cannot hold onto anything that is far out enough that these irregularities influence the iceball or whatever more than the sun's gravity.

a reply to: wildespace

The Hill sphere is a fine concept for two stars or other concentrated objects, but for an irregular object like the galaxy, it's galactic gravitational irregularities that do it. Also, the sun and the iceball are both in the gravitational force of the smoothed average gravitational force of the galaxy, so only the differential effect would be relevant, and with the ratio between the galactic radius and the distance to the iceball being huge, this is negligible. In other words, both the sun and the iceball are in orbit around the galactic center, so the galaxy's gravity doesn't form a Hill sphere.

a reply to: StanFL
How long does it take for gravitational properties to form galaxies? To condense cosmic dust and bodies and reshape and reform them.

originally posted by: ABNARTY
Nothing to get excited about?

Maybe that dude is in the wrong business. I am not an astronomer and I think it's pretty cool.

Makes you wonder what else is 'really' out there versus what's 'expected' to be out there

Most astronomers "expect" there to be plenty of objects similar to this new one and other previously found objects, such as Eris, Sedna, Quaoar, Haumea, Orcus, Makemake, and others. They've been saying for several years now that many objects like this exist.

This newly found object is just one more example to add to that list -- albeit it is the farthest-out example to be found, for now.

The discovery of Eris (which is as large as Pluto and has its own moon) in 2005 is what convinced the International Astronomical Union to create a new class of objects (dwarf planets) and put Eris in Pluto in that class. The reason for doing so was that astronomers even then were pretty sure that 100s of other dwarf planet-like objects most likely exist in the Kuiper Belt and beyond.