NEW in space: Astronomers detect distant solar system with five planets

Astronomers working at the European Southern Observatory (ESO) have discovered a planetary system 127 light-years away that contains at least five planets that orbit the star HD 10180 at distances that follow a regular pattern much like our own solar system.

"We have found what is most likely the system with the most planets yet discovered," said Christophe Lovis, lead author of the paper reporting the result. "This remarkable discovery also highlights the fact that we are now entering a new era in exoplanet research: the study of complex planetary systems and not just of individual planets."

The team of astronomers used ESO's 3.6-metre telescope at La Silla, Chile, for a six-year-long study of HD 10180 located in the southern constellation of Hydrus (the Male Water Snake). The astronomers detected the tiny back and forth motions of the star caused by the complex gravitational attractions from five or more planets. The five strongest signals correspond to planets with Neptune-like masses - between 13 and 25 Earth masses - which orbit the star with periods ranging from about 6 to 600 days. These planets are located between 0.06 and 1.4 times the Earth-Sun distance from their central star.

"We also have good reasons to believe that two other planets are present," says Lovis, adding that one would be a Saturn-like planet and the other would be the least massive exoplanet ever discovered, with a mass of about 1.4 times that of the Earth. The smaller planet is believed to be very close to its host star, at just 2 percent of the Earth-Sun distance. A year on this planet would last only 1.18 Earth-days."

The newly discovered system of planets around HD 10180 is unique in several respects. With at least five Neptune-like planets lying within a distance equivalent to the orbit of Mars, the system is more populated than our solar system in its inner region, and has many more massive planets there. Additionally, the system probably has no Jupiter-like gas giant. In addition, all the planets seem to have almost circular orbits.

Using the new discovery as well as data for other planetary systems, the astronomers found an equivalent of the Titius-Bode law that exists in our solar system: the distances of the planets from their star seem to follow a regular pattern. "This could be a signature of the formation process of these planetary systems," says team member Michel Mayor.

NASA's newest ideas for flying clean and green (photos)

IS A BLACK HOLE 'MIDDLE CHILD' FEASTING IN A DISTANT GALAXY?

                                                                      Black holes are everywhere. They can be left behind as the remnant of a massive star that exploded long ago, being just a few times the mass of our own Sun. Supermassive black holes, containing the mass of million or billions of Suns, sit at the centers of many galaxies. There has been controversy in the astronomical literature about the existence of intermediate mass back holes, and new evidence for one such "middle child" has been presented for an x-ray source in a distant galaxy.

"The candidate's name is HLX-1, and is a bright source of x-rays near a galaxy 300 million light years away. At that distance, it is too bright to be a stellar-mass black hole."

 

 

he emission from the accretion disk around a black hole is limited by the balance between the pressure of the stuff falling in and the pressure of the light itself pushing outwards. For it to be a "normal" black hole, such "ultraluminous" sources would have to have some extra effects thrown in to the model. But this "hyper-ultraluminous" one is really difficult to explain unless it is a few hundred times the mass of the sun, putting it in the elusive intermediate size family.

 

 

There is the possibility, however, that we're looking at a supermassive black hole in an even more distant galaxy that just happens to line up with the galaxy it appears to be in. A very accurate measurement of the x-ray source's position with the Chandra X-Ray Observatory found that it coincided with a source in visible light, and the ratio of the visible light to x-ray light was not consistent with this hypothesis. However, more evidence is necessary.

 

That's where the group led by Klaas Wiersema comes in. They used the Very Large Telescope in Chile to take a spectrum of the visible light of the object. (You can think of that as separating the light into its rainbow of colors.)

This is a tricky situation, as they had to subtract out the spectrum of the galaxy itself. After this, they detected an emission line of hydrogen coming from the mysterious source, and confirmed that it did indeed originate from the galaxy it was near by its redshift. This means that the color of the emission line is slightly redder than you would expect as a result of the galaxy moving away from us in the ever-expanding universe.

Astronomers still aren't sure what makes up with visible light source that coincides with HLX-1. It could be a globular star cluster or the remnants of a dwarf galaxy that was torn apart by host spiral galaxy. Either one is a place where intermediate mass black holes are thought to exist. Though the search for such beasts continues, this is looking like a strong case for their existence in the case of these incredibly bright x-ray sources.

This work has been published in Astrophysical Journal Letters and the preprint is available on arxiv.org. Thanks again to Ned Wright's Cosmology Calculator.(source: discovery channel)
 

Will they able to get success ?

NASA planning mission to visit the sun

We know it's hot up there, but NASA wants to know a bit more about the sun and its atmosphere. And so sometime before 2018, the agency intends to send a spacecraft into the solar atmosphere.

This will mark the first time that a spacecraft from Earth will actually visit a star.

The decision to chart a mission to the sun also realizes a dream that astronomers almost realized a half century ago, when the National Academy of Science's "Simpson Committee" in 1958 recommended a probe to investigate. Several studies were subsequently carried out to test the feasibility of the project, but nothing came of them.

Since NASA has never sent any vehicle this close to Earth's sun, the craft will have to be outfitted with a special shield designed to withstand radiation and temperatures exceeding 2,550 degrees Fahrenheit. A spokesman for NASA said scientists will depend on simulations to guarantee that the probe can cope with that sort of intense heat.