Possible Birth of Tiniest Known Solar System??

ALPiNe · Post by **ALPiNe** » Sat Dec 03, 2005 10:04 pm

Astronomers report a tiny "failed star" possibly in the process of forming a solar system a hundredth the size of our own.

http://www.world-science.net/othernews/ ... larfrm.htm

Strange..But if those little bodies that might be born from the disk are considered planets, then the much controversial Pluto should be considered a planet too without doubt? If so, how are the asteroids in the asteroid belt different from these tiny 'planets' since they orbit around the sun? What then defines a planet anyway? :?

Just some of my thoughts on the discovery...

Cheers,
:cheers:
- ALPiNe

Post by **weixing** » Sun Dec 04, 2005 12:02 am

Hi,

What then defines a planet anyway?

I think we have a similar discussion on this before.

Anyway, there is currently no straightforward definition on what is consider as a planet and what is not. The general definition is: A large object orbit around a star that is not a star itself (doesn't give out it own light).

The problem is how "large" is needed to be consider it as a planet??

Have a nice day.

soulfrost · Post by **soulfrost** » Sun Dec 04, 2005 2:40 am

large and roundish perhaps? =3

its said that had jupiter and mars' gravity didnt interfered the belt, it would have became a planet itself. jupiter's gravity is so strong, it kept all the astroids apart.

added:

perhaps this instead: a roundish and large celestial body which has a core but doesnt produce heat or light like a star?

ALPiNe · Post by **ALPiNe** » Sun Dec 04, 2005 3:52 am

Hi,

Somehow, I feel that the use of size limitations as a factor to define an object as planet seems impractical. Like in this instance, the sun (brown dwarf) is so small that it is the size of a planet. In other words, there is an increased probability that some of its scaled down 'planets' may very well fall behind the parameters that we would use to consider them as planets. If so, then how can we even differentiate these tiny 'planets' from other non-planetary objects that might exist in the solar system itself? :? Even if a limit of 700 km is set (threshold diameter needed to allow gravity to shape an object into a sphere, depending on density), this doesn't prevent asteroids from being included in the list as well. A good example would be Ceres, found in our own Solar system. In fact, at 930 km (580 miles) wide, some astronomers are already having thoughts of reclassifying Ceres as one of the planets!

This is total madness!! :k-crazy:

Hence, I feel that if we were to continue basing our definition of planets on size, we might just end up with having more 'debris' as our planets! :bangwall: Madness! Surely there must be some alternative ways to classify planets other than size? Or is size the only best way to define a planet? :k-worried: Can someone please advice? Thanks!

Cheers,
:cheers:
- ALPiNe

Post by **Airconvent** » Sun Dec 04, 2005 4:12 am

actually the international body responsible for naming planets officially is drawing up a set of criteria on this. of course if you were to argue based on common sense, the cows would come home first...
there has to be a cut off point. so far, they have specified that the body must be so huge that its gravity can support a spherical shape. there is also some specifications about the body being at least 1000km in diameter.
this safely leaves Pluto as a planet (which it should for historical reasons) and would likely place Sedna and "Xena" as the 10th and 11th planet in our solar system. In anycase, Pluto now has at least 3 moons , something kuiper objects are not known to have...