Showing posts with label Gliese 581g. Show all posts
Showing posts with label Gliese 581g. Show all posts
Saturday, February 19, 2011
Still no Sign of Gliese 581g
Image credit: Zina DeretskyFor those of you unfamiliar with the process of finding distant exoplanets, the problem, is that the VAST majority of these objects cannot be observed directly, and even those few extrasolar planets which have been seen, are little more than dots and blurs. In other words, it's not as if we can just point an optical telescope in the planets direction and have a quick look to confirm it's presence. Instead, these distant objects are identified by observing changes in their parent stars, such as shifts in the intensity of the light being emitted by the star or "wobbles" in it's position. From this data, which is typically accumulated over a period of years to build a worthwhile data set, researchers are then able to estimate the size of the planet and the distance at which it orbits it's parent star.
Though the initial re-analysis conducted by the Swedish team did included an additional 2 years worth of observations made by the HARPS Spectrograph in Chile, it did not include data collected by the HIRISE spectrograph in Hawaii. And because the American team used a combination of these two data sets in their research, it's entirely possible that the planet's existence can only be confirmed using both sets. Which is why in January of this year, astro-statistics expert Phillip Gregory of the University of British Columbia, published the first re-analysis of the combined data sets. The results, he too has been unable to confirm the initial observation and has concluded that they were most likely based on statistical error.
While Gregory's findings certainly don't help the case for 581g, that doesn't mean the planet is officially down and out, as subsequent analysis of the data could easily tilt the scales the other direction. As for a final word on the existence of the planet, even if the next study confirms the initial findings, it will likely be years before the planet is either officially accepted or rejected by the scientific community. Hey, no one ever said science was fast.
-CAINE-
Source: wired science
Image credit:Zina Deretsky
Friday, October 15, 2010
Update on Gliese 581g
You may recall that earlier this month a team of US researchers led by astronomer Steven Vogt of the University of California, Santa Cruz, announced that they had discovered a fifth planet in a system orbiting a Red Dwarf (Gliese581) located around 20 light years from earth. More importantly, the planet (officially designated Gliese 581g) was believed to be orbiting it's parent star in it's so called habitable or "Goldilocks" zone, and was therefore deemed capable of sustaining life and dubbed the "most Earth-like" exoplanet ever discovered.
Lead astronomer Steven Vogt took his own his own speculations about the planet even further, publicly stating his belief that the chances of life on the newly discovered planet was 100 percent and in a subsequent interview with i09, renaming the new planet "Zarmina" after his wife, before moving on to described what life and even a human colony might be like on the surface of the tidally locked planet.
Well, as you may already be aware. A group of Swiss researches attempting to confirm the findings of the US research team, announced earlier this week that they had been unable to find any reliable sign of a fifth planet located in Gliese's habitable zone.
Oops.
While this announcement doesn't necessarily mean the existence of the planet won't eventually be confirmed, a complete analysis of the data used to make the discovery-which was collected over a period of eleven years- will take some time, possibly several years, to complete.
-CAINE-
Source:Science/AAAS via:80 Beats
Friday, October 1, 2010
Gliese 581G The New Earth We'll All Soon be Living On - or Not.
Artists depiction of Gliese 581GWednesday the University of California, Santa Cruz announced the discovery of two new planets orbiting the red dwarf star known as Gliese 581, located around twenty light years from earth in what we see as the Libra constellation.
The new planets were both discovered using the Doppler method which measures the shift in the wavelength of light being emitted by a star which, changes when tugged on by the gravity of an object orbiting around it. A planet's mass, the shape of its orbit, and it's distance from it's sun, all effect how the light shifts allowing astronomers to devise specific details about distant objects like these two new Exoplanets of which, the most talked about has been designated Gliese 581G.
With a mass of three to seven times that of the Earth, Gliese 581G is the sixth to be identified orbiting Gliese 581 and is the newest planet in the system to be marked as a potential home for life. Unlike Gliese 581C - which is likely too close to it's star and therefore too hot to sustain liquid water or life - and Gleise581D - which is likely to0 far away from the sun and therefore too cold (or maybe not if it has a thick enough atmosphere) - Gliese 581G orbits it's sun in the so called "Goldilocks Zone" making it the most likely contender yet for a planet capable of sustaining life.
Like the rest of the known planets in the system, 581G follows a circular orbit around it's sun, it completes an orbit every 37 days and is, as far as we can tell, the fourth planet from it's sun. Gliese is also tidally locked to it's star. That means one side of the planet is always facing the sun locking it in a state of perpetual daylight , while the other faces away leaving it in total darkness- which would make the line between shadow and light or terminator, the most habitable place on the planets surface. Researchers also estimate the average temperature on the planet to be between -24 and 10 degrees Fahrenheit.
But contrary to the popular take on this story, which professor of astronomy and astrophysics at the University of California, Santa Cruz, Steven Vogt is not helping by saying things like:
Don't go packing your bags or planning what deep space message you'll be sending to the people of Gliese just yet. While this is an amazing discovery, aside from details about it's mass, orbit, and general surface temperature, not much else can be said for certain about what the planet is actually like. The more important point of this planets discovery is what it could mean for the odds of finding other "Earth-Like" planets capable of sustaining life. Because the fact that a planet like this has been discovered in a system not only within our own galaxy but within 20 light years of our own solar system, is a good indication that habitable planets are in fact abundant throughout our galaxy.
-CAINE-
You can read the original press release from The University of California: HERE. You should also check out Phil Plaits post on this subject as well which is the most detailed post I was able to find on the subject.
The new planets were both discovered using the Doppler method which measures the shift in the wavelength of light being emitted by a star which, changes when tugged on by the gravity of an object orbiting around it. A planet's mass, the shape of its orbit, and it's distance from it's sun, all effect how the light shifts allowing astronomers to devise specific details about distant objects like these two new Exoplanets of which, the most talked about has been designated Gliese 581G.
With a mass of three to seven times that of the Earth, Gliese 581G is the sixth to be identified orbiting Gliese 581 and is the newest planet in the system to be marked as a potential home for life. Unlike Gliese 581C - which is likely too close to it's star and therefore too hot to sustain liquid water or life - and Gleise581D - which is likely to0 far away from the sun and therefore too cold (or maybe not if it has a thick enough atmosphere) - Gliese 581G orbits it's sun in the so called "Goldilocks Zone" making it the most likely contender yet for a planet capable of sustaining life.
Like the rest of the known planets in the system, 581G follows a circular orbit around it's sun, it completes an orbit every 37 days and is, as far as we can tell, the fourth planet from it's sun. Gliese is also tidally locked to it's star. That means one side of the planet is always facing the sun locking it in a state of perpetual daylight , while the other faces away leaving it in total darkness- which would make the line between shadow and light or terminator, the most habitable place on the planets surface. Researchers also estimate the average temperature on the planet to be between -24 and 10 degrees Fahrenheit.
But contrary to the popular take on this story, which professor of astronomy and astrophysics at the University of California, Santa Cruz, Steven Vogt is not helping by saying things like:
"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,"
Don't go packing your bags or planning what deep space message you'll be sending to the people of Gliese just yet. While this is an amazing discovery, aside from details about it's mass, orbit, and general surface temperature, not much else can be said for certain about what the planet is actually like. The more important point of this planets discovery is what it could mean for the odds of finding other "Earth-Like" planets capable of sustaining life. Because the fact that a planet like this has been discovered in a system not only within our own galaxy but within 20 light years of our own solar system, is a good indication that habitable planets are in fact abundant throughout our galaxy.
-CAINE-
You can read the original press release from The University of California: HERE. You should also check out Phil Plaits post on this subject as well which is the most detailed post I was able to find on the subject.
*UPDATE*
Monday, October 11th, 2010 - Astronomer Francesco Pepe of the Geneva Observatory and the Swiss group announced that they had been unable to find any reliable sign of a fifth planet in Gleise's habitable zone.
Oops.
Go HERE for more info.
Monday, October 11th, 2010 - Astronomer Francesco Pepe of the Geneva Observatory and the Swiss group announced that they had been unable to find any reliable sign of a fifth planet in Gleise's habitable zone.
Oops.
Go HERE for more info.
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