Exoplanets large and small, hot and cold...

[Rick]

Astronomers have used a new ground-based technique to study the atmosphere of a planet outside our Solar System.

The work could assist the search for Earth-like planets with traces of organic, or carbon-rich, molecules.

Gases have previously been discerned on exoplanets before, but only by using space-based telescopes.

Astronomers reporting in Nature say their method of spotting methane gas on exoplanets could be extended to many other, ground-based telescopes.

Methane was first spotted on an exoplanet named HD 189733b in 2008 by a group led by Mark Swain of Nasa's Jet Propulsion Laboratory in the US.

More: http://news.bbc.co.uk/1/hi/sci/tech/8493674.stm

[Mike]

Astronomers have discovered a planetary system containing at least five planets that orbit a star called HD 10180, which is much like our own Sun.

The star is 127 light years away, in the southern constellation of Hydrus.

The researchers used the European Southern Observatory (Eso) to monitor light emitted from the system and identify and characterise the planets.

They say this is the "richest" system of exoplanets - planets outside our own Solar System - ever found.

Christophe Lovis from Geneva University's observatory in Switzerland was lead researcher on the study. He said that his team had probably found "the system with the most planets yet discovered".

MORE......... http://www.bbc.co.uk/news/science-environment-11070991

[Tony G]

http://www.wimp.com/systemdiscovery/

Tony G

[Mike]

An Earth-size planet has been spotted orbiting a nearby star at a distance that would makes it not too hot and not too cold — comfortable enough for life to exist, researchers announced today (Sept. 29).

If confirmed, the exoplanet, named Gliese 581g,  would be the first Earth-like world found residing in a star's habitable zone — a region where a planet's temperature could sustain liquid water on its surface.



And the planet's discoverers are optimistic about the prospects for finding life there.

"Personally, given the ubiquity and propensity of life to flourish wherever it can, I would say, my own personal feeling is that the chances of life on this planet are 100 percent," said Steven Vogt, a professor of astronomy and astrophysics at the University of California, Santa Cruz, during a press briefing today. "I have almost no doubt about it."

His colleague, Paul Butler of the Carnegie Institution of Washington, in Washington, D.C., wasn't willing to put a number on the odds of life, though he admitted he's optimistic.

"It's both an incremental and monumental discovery," Sara Seager, an astrophysicist at the Massachusetts Institute of Technology, told SPACE.com. Incremental because the method used to find Gliese 581g already has found several planets most of the known planets, both super-Earths, more massive than our own world outside their stars' habitable zone, along with non-Earth-like planets within the habitable zone.

"It really is monumental if you accept this as the first Earth-like planet ever found in the star's habitable zone," said Seager, who was not directly involved in the discovery.

Vogt, Butler and their colleagues will detail the planet finding in the Astrophysical Journal.

The newfound planet joins more than 400 other alien worlds known to date. Most are huge gas giants, though several are just a few times the mass of Earth.

http://www.space.com/scienceastronomy/earth-like-exoplanet-possibly-habitable-100929.html

[Mike]

It would need a moon to stabilise it's wobble to make it viable for life. But it shows how it won't be long before Earth sized planets are routine discovery.

[Tony G]

A group of boffins claims to have spied the "first discovered terrestrial-mass exoplanet in the habitable zone", the BBC reports.

The planet in question is orbiting the much-studied star Gliese 581, some 20 light-years away in the constellation Libra. Of the possible worlds orbiting the red M-class sun, Gliese 581d had already been proposed as a repository of water, although studies suggested its distance from the solar system's centre means it would be too cold for liquid H2O.

http://www.theregister.co.uk/2011/05/17/blighty_exoplanet/

Tony G

PS......................................I don't suppose they would be doing any decent observing from there then.

[Rick]

NASA's Kepler Mission Discovers a World Orbiting Two Stars

The existence of a world with a double sunset, as portrayed in the film Star Wars more than 30 years ago, is now scientific fact. NASA's Kepler mission has made the first unambiguous detection of a circumbinary planet -- a planet orbiting two stars -- 200 light-years from Earth.

Unlike Star Wars' Tatooine, the planet is cold, gaseous and not thought to harbor life, but its discovery demonstrates the diversity of planets in our galaxy. Previous research has hinted at the existence of circumbinary planets, but clear confirmation proved elusive. Kepler detected such a planet, known as Kepler-16b, by observing transits, where the brightness of a parent star dims from the planet crossing in front of it.

More: http://www.nasa.gov/mission_pages/kepler/news/kepler-16b.html

[Rick]

Astronomers Find Elusive Planets in Decade-Old Hubble Data

In a painstaking reanalysis of images taken in 1998 by NASA's Hubble Space Telescope, astronomers have found visual evidence for two exoplanets that went undetected back then. Exoplanets are planets that orbit stars beyond our sun.

Finding these hidden gems in the Hubble archive gives astronomers an invaluable time machine for comparing much earlier planet orbital motion data to more recent observations. It also demonstrates a novel approach for planet hunting in archival Hubble data.

By finding the planets in multiple images spaced over years of time, the orbits of the planets can be tracked. Knowing the orbits is critical to understanding the behavior of multiple-planet systems because massive planets can perturb each other's orbits.

More: http://www.jpl.nasa.gov/news/news.cfm?release=2011-315

[Rocket Pooch]

Kepler 22-b: Earth-like planet confirmed

Astronomers have confirmed the existence of an Earth-like planet in the "habitable zone" around a star not unlike our own.

The planet, Kepler 22-b, lies about 600 light-years away and is about 2.4 times the size of Earth, and has a temperature of about 22C.

It is the closest confirmed planet yet to one like ours - an "Earth 2.0".

However, the team does not yet know if Kepler 22-b is made mostly of rock, gas or liquid.

During the conference at which the result was announced, the Kepler team said that it had spotted some 1,094 new candidate planets.

More: http://www.bbc.co.uk/news/science-environment-16040655

[JohnP]

Anyone know if it is possible to image the star that Kepler 22b orbits - if so what are the coords...?

[Mike]

Looks like it:

From Wikipedia....

Kepler 22 (aka Kepler-22a) is a G-type star, approximately 600 light years from Earth that holds within its solar system the first planet identified to be within an Earth-like habitable zone. Kepler 22 is slightly smaller and cooler than the Sun. It is located between the constellations Cygnus and Lyra at Right Ascension 19h 16m 52.2sec and Declination +47deg 53min 4.2sec.[2]

Apparently it is 11th Magnitude. So well within the reach of a modest scope and a fairly short exposure on a cooled cam.

[Rick]

Citizens Discover Four-Star Planet with NASA's Kepler

The discovery of planets continues to expand beyond the domain of professional astronomers. A joint effort of amateur astronomers and scientists has led to the first reported case of a planet orbiting a double star that, in turn, is orbited by a second distant pair of stars.

Aided by volunteer citizen scientists using the Planethunters.org website, a Yale-led international team of astronomers identified and confirmed discovery of the phenomenon, called a circumbinary planet in a four-star system. Only six planets are known to orbit two stars but none of these are orbited by a distant binary.

Coined PH1, the planet was identified by the citizen scientists participating in Planet Hunters, a Yale-led program that enlists the public to review astronomical data from NASA's Kepler spacecraft for signs of planet transits of distant stars.

More: http://www.jpl.nasa.gov/news/news.php?release=2012-324

[Rick]

Exoplanet around Alpha Centauri is nearest-ever

Astronomers have found the nearest planet outside our Solar System, circling one of the stars of Alpha Centauri just four light-years away.

The planet has at minimum the same mass as Earth, but circles its star far closer than Mercury orbits our Sun.

It is therefore outside the "habitable zone" denoting the possibility of life, as the researchers report in Nature.

However, studies on exoplanets increasingly show that a star with one planet is likely to have several.

At the very least, the work answers the question first posed in ancient times about planets around our nearest stellar neighbours.

The closest star to the Sun is Proxima Centauri, which is believed to be part of a three-star system that includes the brighter stars Alpha Centauri A and B.

The planet was found near Alpha Centauri B by the Harps instrument at the European Southern Observatory's La Silla facility in Chile.

More: http://www.bbc.co.uk/news/science-environment-19959531

[Rick]

Closest Star System Found in a Century

NASA's Wide-field Infrared Survey Explorer (WISE) has discovered a pair of stars that has taken over the title for the third-closest star system to the sun. The duo is the closest star system discovered since 1916.

Both stars in the new binary system are "brown dwarfs," which are stars that are too small in mass to ever become hot enough to ignite hydrogen fusion. As a result, they are very cool and dim, resembling a giant planet like Jupiter more than a bright star like the sun.

"The distance to this brown dwarf pair is 6.5 light-years -- so close that Earth's television transmissions from 2006 are now arriving there," said Kevin Luhman, an associate professor of astronomy and astrophysics at Penn State University, University Park, Pa., and a researcher in Penn State's Center for Exoplanets and Habitable Worlds.

More: http://www.jpl.nasa.gov/news/news.php?release=2013-090

[MarkS]

"The distance to this brown dwarf pair is 6.5 light-years -- so close that Earth's television transmissions from 2006 are now arriving there," said Kevin Luhman,

Cool! 

That means they can begin watching the first series of "Life on Mars". 
Seems kind of appropriate!