Having detected an exoplanet circling Alpha Centauri B in 2012, astronomers have now narrowed its mass to one to three times that of Earth, making this closest exoplanet an Earth-sized planet.
Using Kepler astronomers have discovered a Uranus-sized exoplanet with the longest known orbit, 704 days.
Kepler-421b orbits an orange, type K star that is cooler and dimmer than our Sun. It circles the star at a distance of about 110 million miles. As a result, this Uranus-sized planet is chilled to a temperature of -135° Fahrenheit.
As the name implies, Kepler-421b was discovered using data from NASA’s Kepler spacecraft. Kepler was uniquely suited to make this discovery. The spacecraft stared at the same patch of sky for 4 years, watching for stars that dim as planets cross in front of them. No other existing or planned mission shows such long-term, dedicated focus. Despite its patience, Kepler only detected two transits of Kepler-421b due to that world’s extremely long orbital period.
The planet’s orbit places it beyond the “snow line” – the dividing line between rocky and gas planets. Outside of the snow line, water condenses into ice grains that stick together to build gas giant planets.
Posted from Bright Angel Lodge on the rim of the Grand Canyon.
Worlds without end: Astronomers on Monday announced the discovery of a rocky exoplanet that is seventeen times the mass of Earth.
The best image yet of an exoplanet orbiting another star.
For the first time astronomers think they have measured the rotation rate of an exoplanet, thus determining the length of its day.
Ignas Snellen and his colleagues at Leiden University in the Netherlands report in Nature1 that a gaseous planet orbiting the star β Pictoris rotates at 25 kilometres per second at its equator — faster than any planet in the Solar System and about 50 times faster than Earth. A day on the planet, called β Pictoris b, lasts just over eight hours, even though the planet has a diameter more than 16 times that of Earth’s and carries more than 3,000 times Earth’s heft.
This result falls under my category of “the uncertainty of science.” Though quite cool, and based on real data, the uncertainties are great. Don’t bet the house that this result will stand up to closer observations in the future.
A direct image of an exoplanet.
What’s most amazing is this image was taken by a ground-based telescope.
The uncertainty of science: Astronomers discover an exoplanet that their theories say shouldn’t exist.
Astronomers have found evidence of the remains of an exoplanet that they think was once wet and rocky.
Using observations obtained with the Hubble Space Telescope and the large telescopes of the W. M. Keck Observatory , they found an excess of oxygen – a chemical signature that indicates that the debris had once been part of a bigger body originally composed of 26 per cent water by mass. By contrast, only approximately 0.023 per cent of the Earth’s mass is water.
From what I can gather, the actual data here is somewhat skimpy, requring a lot of assumptions for the scientists to come to this conclusion. Nonetheless, the data is interesting and very tantalizing.
Posted from Memphis, Tennessee.
A blue exoplanet the size of Jupiter where glass rains sideways.
Astronomers take an image of an exoplanet only 300 light years away.
Water and carbon monoxide have been detected in the atmosphere of a super-sized exoplanet 129 light years away.
Tracking the orbit of the exoplanet in Fomalhaut’s debris disk.
Billions and billions! Using data from a solar system detected by the Kepler space telescope, astronomers now extrapolate that there are at least as many planets as stars in our galaxy.
Another Earth just twelve light years away?
A planet without a star, only 100 light years away.
Worlds without end: Astronomers have found a super-earth exoplanet inside its star’s habitable zone.
The planet is large enough that it might be more like Neptune, but if it should have any earth-sized moons they will definitely be capable of supporting life.
Update: The science paper included a wonderful graphic comparing the solar system of this star with that of our own solar system. I have posted this graphic below the fold. HD40307g is the potentially habitable planet.
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The uncertainty of science: A new study suggests that the exoplanet orbiting the star Formalhaut that was supposedly imaged and then later theorized to be nothing more than a dust cloud might be a planet after all.
Big news: Astronomers have discovered that the nearest star to the Earth, Alpha Centauri, has an exoplanet only slightly heavier than the Earth.
Alpha Centauri is actually a triple star system, with two sunlike stars in a tight orbit around each other and a third star far out orbiting them both. The exoplanet orbits one of the inner stars every 3.2 days.
More details from Nature here.
Astronomers have discovered the first exoplanet smaller than Earth.
The University of Central Florida has detected what could be its first planet, only two-thirds the size of Earth and located right around the corner, cosmically speaking, at a mere 33-light years away. The exoplanet candidate called UCF 1.01, is close to its star, so close it goes around the star in 1.4 days. The planet’s surface likely reaches temperatures of more than 1,000 degrees Fahrenheit. The discoverers believe that it has no atmosphere, is only two-thirds the gravity of Earth and that its surface may be volcanic or molten.
What is especially remarkable about this discovery is that the scientists used the Spitzer Space Telescope to do it, detecting the planet’s transits across the star’s face, just like Kepler. Spitzer was not designed to be able to do this.
A planet turning to dust.
Another superEarth has been found orbiting a star in the habitable zone.
An M-class dwarf star called GJ 667C, which is 22 light-years away from Earth, had previously been observed to have a super-Earth (called GJ 667Cb) that orbited the star in only 7.2 days, making it too close to the star, and thus too hot, to support life.
The study started with the aim of learning more about the orbit of GJ 667Cb. But the research team found a clear signal of a new planet (GJ 667Cc) with an orbital period of 28.15 days and a minimum mass of 4.5 times that of Earth.
Though the planet is much closer to its star than the Earth, the star itself is much smaller and dimmer, so overall the planet gets about the same amount of energy as the Earth.
Astronomers question the legitimacy of the first exoplanet to be directly imaged.
Astronomers have discovered a planet literally made of diamond.
The new planet is far denser than any other known so far and consists largely of carbon. Because it is so dense, scientists calculate the carbon must be crystalline, so a large part of this strange world will effectively be diamond.
Is the extrasolar planet Gliese 581d habitable? Maybe.
Bad news for Gliese 581g, the first exoplanet thought to orbit its star in the habitable zone: A new study can’t find it.
Can we find trees on other planets?
