Brown dwarfs raise plenty of questions, not the least of which is how they form. Work up to some fifteen times Jupiter's mass and the planet in question starts to look more like a brown dwarf, a 'failed star' that cannot sustain fusion at its core. Somewhere around 75 Jupiter masses long-term fusion ignites and you're in the territory of a true star. This brown dwarf zone between the two poles makes these objects provocative -- do they form the way most planets seem to do by collecting more and more rocky materials and eventually a gas envelope? Or does a brown dwarf form, like a star, through the gravitational collapse of a gas cloud? The latter idea gets a boost from recent work from the Harvard-Smithsonian Center for Astrophysics. Astronomers have now found a stream of carbon monoxide flowing out from a young brown dwarf known as ISO-Oph 102. This gets interesting at several levels, the first being that the outflow from the dwarf resembles what happens in larger stars as they...

It hasn't been all that long since Hanny van Arkel, a Dutch school teacher, lent her name to the anomalous object since known as 'Hanny's Voorwerp.' Working with data from the Galaxy Zoo project, van Arkel was scanning galaxy images when she ran across what seemed to be a green blob of extremely hot gas with a hole in its center. That hole turned out to be 16000 light years across, its cause unknown, and the object itself seemed to be lit by an unseen source. Theories abounded, including a 'light echo' from a defunct quasar in a nearby galaxy. And then there was the fact that the remarkably hot object (15000 degrees Celsius or more) was not only enormous but also empty of stars. Baffling astronomers for the past year, Hanny's Voorwerp may now be swimming into sharper focus. An international team has been observing both the object and the nearby galaxy IC2497 using the Westerbork Synthesis Radio Telescope, with results that indicate the presence of a jet coming from a massive black...