Exoplanets large and small, hot and cold...

[Rick]

Astronomers have sighted the smallest extrasolar planet yet orbiting a normal star - a distant world just three times the size of our own.

Discovering a planet with a similar mass to that of Earth is considered the "holy grail" of research into planets that lie outside our Solar System.

It is vital because researchers want to find other worlds that could host life.

The planet orbits a star which is itself of such low mass it may in fact be a "failed star", or brown dwarf.

More: http://news.bbc.co.uk/2/hi/science/nature/7432114.stm

[mickw]

European researchers said on Monday they discovered a batch of three "super-Earths" orbiting a nearby star, and two other solar systems with small planets as well.
They said their findings, presented at a conference in France, suggest that Earth-like planets may be very common.

"Does every single star harbour planets and, if yes, how many?" asked Michel Mayor of Switzerland's Geneva Observatory. "We may not yet know the answer but we are making huge progress towards it," Mayor said in a statement.

The trio of planets orbit a star slightly less massive than our Sun, 42 light-years away towards the southern Doradus and Pictor constellations. A light-year is the distance light can travel in one year at a speed of 186,000 miles (300,000 km) a second, or about 6 trillion miles (9.5 trillion km).

More:   http://uk.news.yahoo.com/rtrs/20080616/tsc-uk-space-planets-011ccfa.html

[mickw]

A trio of planets called super-Earths has been spotted orbiting a sun-like star, astrophysicists announced today at an international conference in France.

Super-Earths are more massive than Earth but less massive than Uranus and Neptune. Spotting true Earth-sized planets is challenging with current technology, but the presence of super-Earths suggests finding a world like ours is just a matter of time, researchers say.

More:  http://news.yahoo.com/s/space/20080616/sc_space/threesuperearthsfoundorbitingonestar

[Rick]

Astronomers have identified a trio of so-called "super-Earths" - rocky planets between two and 10 times the mass of Earth.

The three new planets were detected using the Harps instrument at the La Silla Observatory in central Chile.

The star they circle is slightly smaller than our Sun, and is located 42 light-years away near the southern Doradus and Pictor constellations.

The discoveries were announced at an astronomy conference in Nantes, France.

More: http://news.bbc.co.uk/2/hi/science/nature/7457307.stm

[mickw]

Little more than a decade ago, astronomers Michel Mayor and Didier Queloz announced the discovery of a planet in orbit about 51 Pegasi. It rushes around its sun in just over 4 days, seared to a temperature of 1,000 degrees Celsius (about 1,800 degrees Fahrenheit). Today, we call this sort of planet a "hot Jupiter." This was the first planet found orbiting a main sequence star — a star similar to our Sun. Earlier, the irregular beat of a pulsar revealed the cindered remains of planets orbiting the corpse of a dead star. Most likely, they formed after the supernova death of their parent star, which indicates that planet formation is a likely outcome from a disk of material. These pulsar planets are not good places to live. But discovering 51 Pegasi around a more ordinary star kicked off a great planetary gold rush.

More:   http://www.space.com/searchforlife/080619-seti-extrasolar-earths.html

[mickw]

Astronomers have taken what may the first picture of a planet orbiting a star similar to the sun.

This distant world is giant (about eight times the mass of Jupiter) and lies far out from its star (about 330 times the Earth-Sun distance). But for all the planet's strangeness, its star is quite like our own sun.

Previously, the only photographed extrasolar planets have belonged to tiny, dim stars known as brown dwarfs. And while hundreds of exoplanets have been detected by noting their gravitational tug on their parent stars, it is rare to find one large enough to image directly.

More:    http://www.space.com/scienceastronomy/080915-first-exoplanet-picture.html

[Whitters]

The NASA/ESA Hubble Space Telescope has taken the first visible light snapshot of a planet circling another star.

Estimated to be no more than three times Jupiter's mass, the planet, called Fomalhaut b, orbits the bright southern star Fomalhaut, located 25 light-years away in the constellation Piscis Austrinus (the Southern Fish).

Fomalhaut has been a candidate for planet hunting ever since an excess of dust was discovered around the star in the early 1980s by the US-UK-Dutch Infrared Astronomy Satellite (IRAS).

More: http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=43721

[Mike]

Amazing. Just makes you wonder what we will be seeing once there are orbiting sscopes good enough to see detail on earth sized planets!

[Rick]

The first pictures of planets outside our Solar System have been taken, two groups report in the journal Science.

Visible and infrared images have been snapped of a planet orbiting a star 25 light-years away.

The planet is believed to be the coolest, lowest-mass object ever seen outside our own solar neighbourhood.

More: http://news.bbc.co.uk/1/hi/sci/tech/7725584.stm

APOD:  http://apod.nasa.gov/apod/ap081114.html

[Rick]

The Hubble space telescope has captured the first visible-light image of an exoplanet orbiting a star - a body no greater than three Jupiter masses, gravitationally-bound to Fomalhaut in the constellation Piscis Australis.

Dubbed Fomalhaut b, the planet lies at 10.7 billion miles from Fomalhaut and 1.8 billion miles inside the inner edge of a debris disk surrounding the star, described by NASA as "similar to the Kuiper Belt".

More: http://www.theregister.co.uk/2008/11/14/fomalhaut_b/

[Carole]

What's the strange gap at 11 o'clock.  I would have thought this could be the arm of the occlusion disc except there is a patch of dust on it and Formalhaut is still visible.

Any thoughts?

[Rick]

No comment: http://ars.userfriendly.org/cartoons/?id=20081117

[Rick]

Any thoughts?

I suspect the images are composites...

[Carole]

I suspect the images are composites...

Ah yes, that might explain it, never thought of that.

Thanks Rick

[Rick]

The Hubble Space Telescope has detected carbon dioxide (CO2) in the atmosphere of a planet orbiting a star 63 light years away. NASA says this is "an important step toward finding chemical biotracers of extraterrestrial life".

The planet in question is of the type known as a "hot Jupiter", because such planets are like Jupiter but much hotter*. It is a huge ball of gas rather than a solid world, and orbits so closely to its sun that the year is only a couple of Earth days long. Its parent star, the orange dwarf HD189733, lies in the constellation Vulpecula.

More: http://www.theregister.co.uk/2008/12/10/nasa_co2_gas_giant/

*Duh.