Wednesday, January 9, 2013
More Planets Out There and Too Much Astronomy News
This week, 2800 astronomers are gathered in Southern California for the winter meeting of the American Astronomical Society and the news from the meeting is coming so fast and furious even seasoned astronomy fans are somewhat overwhelmed. Let me just list a few of the news stories for you for now and we will explore some of them further in future posts.
The picture I have attached above shows new information about the planet orbiting the star Fomalhaut, the 17th brightest star in the night sky (and, at a distance of only 25 light years, one of the closer stars to us.) The faint distant planet, one of the first planets outside the solar system to be actually photographed, is shown here in an image from the Hubble Space Telescope.
In the image, the bright star has been covered up by a dark disk (in the middle) that the Hubble telescope can use to block light. That allows us to see the planet and the huge dusty disk surrounding the star. The planet has an orbit that takes it around its star in about 2000 Earth years. (Compare that to a 1-year orbit for Earth and a 12-year orbit for Jupiter.) So some astronomical commentators are suggesting it might be more of a giant comet or a distant ice-dwarf (like Pluto) and not really the kind of planet we first think of when we talk about planets.
In a related story, the Kepler mission team, searching for planets that "eclipse" their stars (see earlier posts of mine on this mission), is reporting 461 new planet candidates, bringing their total number of possible planets to 2,740! Four of the new candidates are less than twice the size of Earth and orbiting where conditions are Earth-like.
Nest, teams of astronomers using orbiting telescopes have filed the most detailed "weather report" yet about clouds in the atmosphere of a "brown dwarf" -- the name we give to a failed star. These objects begin life like stars do, but can't keep making energy in the way our Sun and others stars can. It's amazing that we can now probe for the existence of Earth-sized clouds in the outer layers of these remote, faint objects.
Plus there is the possible discovery of floating icebergs on Saturn's moon Titan, an asteroid belt around the bright star Vega, and much more. (The reason there is so much news all at once is that astronomers save their discoveries for announcement at this annual winter meeting, so they can share the results with their colleagues and argue about them right then and there. With almost 3000 astronomers gathered in the same convention center, there is a good clump of experts to dissect and admire each discovery.)
More details in posts to come.