When astronomers started reporting free-floating planetary mass objects in 2000, they dubbed them "isolated giant planets." That simple description set off a heated debate about whether the free-floaters should be bestowed planethood.
Thomas Haworth, an astrophysicist at the University of Cambridge, is delving deeper into how globulettes might transition from extremely tiny gas clouds to full-fledged free-floaters. His simulations show that the tiny globs of gas don't necessarily have enough gravity to collapse in on themselves and condense to form stars.
Such comparisons could reveal how different free-floaters formed and lend credence to Luhman's argument that if it formed like a star, it's a star, and if it formed like a planet, it's a planet.
NBC News reported that (http://www.nbcnews.com/science/astronomers-say-theyve-spotted-lonesome-planet-without-sun-8C11366309) similar free-floaters
have been spotted in the past but they were not easily identified if they were just falling stars or orphaned planets.
Scientists think that most them may have formed like stars, in isolation from contracting gas clouds, but some of the puniest free-floaters
may have formed like planets around a star and later been ejected.
aren't technically planets because they don't orbit a star.
These "free-floaters" or "planemos" remain controversial, because some astronomers argue that they are low-mass brown dwarfs.
They found that many very cool free-floaters in the Upper Scorpius Association exhibit narrow spectral lines, which indicates atmospheric pressure that one would expect in a planetary-mass object's relatively low-gravity environment (S&T: October 2004, page 20).
In theory, the roaming bodies and more than 100 other recently discovered "free-floaters," as researchers are calling them, could have orbited stars until sibling planets pushed them out.
That would imply that the least massive of the free-floaters could not have formed as stars do.
If the objects are as abundant in other clusters, the number of free-floaters dispersed through the Milky Way could rival the number of stars.
Roche of the University of Oxford examined another star cluster, Orion's Trapezium, they found hints of 13 free-floaters with planetlike masses.