Astronomers discover largest solar system (opens in new tab)

(bbc.com)

69 pointskrislig10y ago16 comments

16 comments

12 comments · 2 top-level

__michal10y ago· 7 in thread

Another system is no longer "solar", just planetary, as it evolves around another star, not the Sun. Or am I making this up?

laretluval10y ago

http://www.merriam-webster.com/dictionary/solar%20system

Full Definition of solar system : the sun together with the group of celestial bodies that are held by its attraction and revolve around it; also : a similar system centered on another star

jessriedel10y ago

Yea, this is a case where different communities (astronomers vs. laymen) have different definitions. Astronomers use the restrictive definition of "solar" for just for "sol", but they also have a more expansive definition of "metal" to mean "anything but hydrogen and helium".

jewel10y ago

It'd be nice to call it a stellar system for consistency, but that already means a group of interacting stars. Planetary system or exoplanetary system seems to be the right term to use.

sdrothrock10y ago

Huh, "planetary system" wouldn't been my first choice. By analogy, if a solar system is a system about the Sun, a planetary system would seem to me to be a system about a planet e.g. Jupiter and its moons.

2 more replies

overcast10y ago

I don't think most people understand that our star is called Sol.

gammarator10y ago

Yeah, usually astronomers say "extrasolar planet", or exoplanet for short.

hartror10y ago

You are correct.

aexaey10y ago· 3 in thread

> The planet, known as 2MASS J2126-8140, is between 12 and 15 times the mass of Jupiter.

Wouldn't object on the higher end of this range be regarded as a brown dwarf, making this system a binary star rather than a planet system?

mapt10y ago

The distinction is not a bright-line, and is not settled consensus: https://en.wikipedia.org/wiki/Brown_dwarf

slg10y ago

It seems the more we learn about the object out there, the more varied they appear, and the clearer it becomes that our naming conventions are completely arbitrary.

meric10y ago

Brown dwarfs are substellar objects[1]

Perhaps if it doesn't make it as a star, then it's not binary? It's not quite a planet system, but maybe one can call it a "Solar system"?

[1] https://en.wikipedia.org/wiki/Brown_dwarf

This might be interesting. In the same article, they call a pair of brown dwarves a "a binary system" rather than a binary star.

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