Astronomers discover largest solar system | Hacker News Reader

Astronomers discover largest solar system

bbc.com

69 pointskrislig16 comments

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

You are correct.

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

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.

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.

Maybe "planetary system" is a system of planets, but a "planet system", like the "Jupiter system", would be the system for a single planet. That would make "stellar system" sensible too. Furthermore, a planetary system associated with a single star is a "star system".

One more option: "exosolar system".

That makes a lot of sense!

How about a "star+planet(s) system". Unambiguous, but can't easily pronounce.

Nitpicks:

First, I would call it the Solar System. (Not any solar system, mind you.) That would be in line with existing nomenclature in which the Solar System¹ is the name of our planetary system².

Second, "moon" is not the best term (although I know it's in use like a lot of other "liberal English" words) and I would prefer "(natural) satellite"³ for this generic meaning and leave "moon" for the (Earth's) Moon⁴.

¹ https://en.wikipedia.org/wiki/Solar_System

² https://en.wikipedia.org/wiki/Planetary_system

³ https://en.wikipedia.org/wiki/Natural_satellite

⁴ https://en.wikipedia.org/wiki/Moon

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

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".

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

> 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?

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

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.

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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