The cool thing about science is that it isn't the normal everyday things that you learn new things from. It's the things that seem a little unusual. Unusual like a tiny star which goes by the name of 2M044144, a mere 450 light years away in the Taurus molecular cloud. Well... I say "star". Really, 2M044144 is barely a star at all. It's a brown dwarf. A stellar runt, too small to burn hydrogen. The interesting thing is that this tiny star has a planet in tow. Not just any planet, but a giant planet!In fact, with an estimated mass of between 5 and 10 jupiter masses, this is a sizeable planet. Much larger and it would be capable of being a brown dwarf itself. It's also estimated as being only around 1 million years old, which is about the same age estimated for the star itself. In short, there was no way that this planet (which is in a close orbit at only around 24 AU away) could have formed the way a "regular" planet does. It simply hasn't had the time.
Remarkably, that means that this planet must have condensed directly from the same cloud of gas and dust that the star did. Had it accumulated more mass, the whole system would have been a binary star. Astronomers found fairly recently that stars can form the way planets do. Apparently, planets can form the way stars do too!
Which makes you wonder how many interstellar planets might be drifting around in interstellar space, having formed directly. Born the way stars are, but forever dark and silent. Perhaps there may be many more planets in our galaxy than we realise.
The paper about the 2M044144 system is available from the Astrophysical Journal.
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