Miniature Solar System

[Bill McBlueState]

From Universe Today

Scientists using a combination of ground-based and orbiting telescopes have discovered a failed star, less than one-hundredth the mass of the Sun, possibly in the process of forming a solar system. It is the smallest known star-like object to harbor what appears to be a planet-forming disk of rocky and gaseous debris, which one day could evolve into tiny planets and create a solar system in miniature. A team led by Kevin Luhman, assistant professor of astronomy and astrophysics at Penn State University, will discuss this finding in the 10 December 2005 issue of Astrophysical Journal Letters.

The discovered object, called a brown dwarf, is described as a "failed star" because it is not massive enough to sustain nuclear fusion like our Sun. The object is only eight times more massive than Jupiter. The fact that a brown dwarf this small could be in the midst of creating a solar system challenges the very definition of star, planet, moon and solar system.

"Our goal is to determine the smallest 'sun' with evidence for planet formation," said Luhman. "Here we have a sun that is so small it is the size of a planet. The question then becomes, what do we call any little bodies that might be born from this disk: planets or moons?" If this protoplanetary disk does form into planets, the whole system would be a miniaturized version of our solar system -- with the central "sun", the planets, and their orbits all roughly 100 times smaller.

Luhman's team detected the brown dwarf, called Cha 110913-773444, with NASA's Spitzer Space Telescope, the Hubble Space Telescope, and two telescopes in the Chilean Andes, the Blanco telescope of the Cerro Tololo Inter-American Observatory and the Gemini South telescope, both international collaborations funded in part by the National Science Foundation. Luhman led a similar observation last year that uncovered a 15-Jupiter-mass brown dwarf with a protoplanetary disk.

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[htuttle]

1. Does anything indicate the existence of 'dark matter'...

...other than the fact that there seems to be a lot of matter 'missing'?

If so, there might not be any dark matter at all, but instead the missing matter might be mostly tied up in non-luminous (or barely luminous) systems like this.

Just a thought I had reading this. :shrug:

[Salviati]

2. And you're not the first to think of this...

when you hear astrophysicists talking about MACHOs that's what they're talking about. The acronym stands for Massive Compact Halo Objects. Another type of dark matter candidate that you may hear about are WIMPs, i.e. Weakly Interacting Massive Particles. The discovery that neutrinos do indeed have a slight mass puts them in this catagory, and their mass has accounted for a small fraction of the theorized dark matter out there...

[rman]

3. very true;

In fact quite a bit of "dark matter" has been found since its existence was first proposed. Turned out to be normal matter that was undetectable because the detection equipment wasn't sensitive enough. Much of this matter is in the form of huge intergalactic clouds of hydrogen.
Though that still doesn't explain the way galaxies rotate.