via Livescience, the satory of 3 Dutch undergradate students that have discovered a planet, and a mightly unique one as it it the first to be discoverdd orbiting around a fast rotating star and is also the hottest star (at 12,000 degrees F) ever found to have a planet.
"It is exciting not just to find a planet, but to find one as unusual as this one; it turns out to be the first planet discovered around a fast-rotating star, and it's also the hottest star found with a planet," said one of the planet's discoverers, Meta de Hoon of Leiden University in The Netherlands. The other Leiden-student team members included Remco van der Burg and Francis Vuijsje."
The planet called OGLE2-TR-L9b, is around 5 Jupiter masses and orbits the star devery 2 1/2 days, and was found by the transit method (measuring the slightly detectable drop in light as the planet passes in front of its parent star). It is extremely close to its star, only .03 astronomical units. Their discovery was confirmed by the European Space Agency's VLT (Very Large Telescope) in Chile.
Very cool achievement for these young people.
Showing posts with label Science - Extrasolar Planets. Show all posts
Showing posts with label Science - Extrasolar Planets. Show all posts
Tuesday, December 09, 2008
Monday, November 24, 2008
Carbon Dioxide Discovered in Alien Planet Atmosphere
Astronomers have announced the discovery of carbon dioxide on an alien exoplanet orbiting a star 65 light years from our own system. While the planet, HD 189733b, is a"hot" Jupiter orbiting too close to its parent star to support life, it is remarkable that we have now been able to determine how to discover three of the four major chemical compounds that are indicators of alien life.
" "This is the first detection of carbon dioxide in the atmosphere of an extrasolar planet, which means that three of the Big Four biomarkers for habitable/inhabited worlds have now been seen: water, methane, and now carbon dioxide," explained Alan Boss, a planet-formation theorist at the Carnegie Institution of Washington who was not involved in the finding. "The only one that has not yet been detected is oxygen/ozone."
Boss told SPACE.com that the detections provide "proof of concept" for what astronomers would search for in looking at an Earth-like world. The detection of carbon dioxide, Boss said, was made with a low degree of resolving power, the sort that could be provided by NASA's planned Terrestrial Planet Finder."
The discovery was made by Giovanna Tinetti of University College in London, England, and used a novel technique of measuring the light from the star both when the planet was in front of the star and behind the star, and using the difference to determine what light was coming from the planet and doing a spectral analysis.
Pretty cool.
" "This is the first detection of carbon dioxide in the atmosphere of an extrasolar planet, which means that three of the Big Four biomarkers for habitable/inhabited worlds have now been seen: water, methane, and now carbon dioxide," explained Alan Boss, a planet-formation theorist at the Carnegie Institution of Washington who was not involved in the finding. "The only one that has not yet been detected is oxygen/ozone."
Boss told SPACE.com that the detections provide "proof of concept" for what astronomers would search for in looking at an Earth-like world. The detection of carbon dioxide, Boss said, was made with a low degree of resolving power, the sort that could be provided by NASA's planned Terrestrial Planet Finder."
The discovery was made by Giovanna Tinetti of University College in London, England, and used a novel technique of measuring the light from the star both when the planet was in front of the star and behind the star, and using the difference to determine what light was coming from the planet and doing a spectral analysis.
Pretty cool.
Wednesday, October 08, 2008
Oddball Object Discovered by COROT
via ScienceDaily, the European COROT space observatory has discovered a very unusual object orbiting a distant star. While a number of exoplanets have been discovered in short period orbits, this object defies classification due to its unusual mass. Every one of the "hot Jupiters" found by astronomers so far range in size up to 12 Jupiter masses, while failed stars, so-called brown dwarfs, start off at around 70 Jupiter masses. This object, called COROT-exo-3b, is twenty Jupiter masses, yet is around the same diameter. This makes the object around twice as dense as lead.
"The object, named COROT-exo-3b, is about the size of Jupiter, but packs more than 20 times the mass. It takes only 4 days and 6 hours to orbit its parent star, which is slightly larger than the Sun. COROT-exo-3b was found as the satellite observed the drop in the brightness of the star each time the object (COROT-exo-3b) passed in front. "We were taken by surprise when we found this massive object orbiting so close to its parent star", said Dr Magali Deleuil from the Laboratoire d'Astrophysique de Marseille (LAM), leader of the team that made the discovery. She added, "COROT-exo-3b is really unique - we’re still debating its nature."
"The object, named COROT-exo-3b, is about the size of Jupiter, but packs more than 20 times the mass. It takes only 4 days and 6 hours to orbit its parent star, which is slightly larger than the Sun. COROT-exo-3b was found as the satellite observed the drop in the brightness of the star each time the object (COROT-exo-3b) passed in front. "We were taken by surprise when we found this massive object orbiting so close to its parent star", said Dr Magali Deleuil from the Laboratoire d'Astrophysique de Marseille (LAM), leader of the team that made the discovery. She added, "COROT-exo-3b is really unique - we’re still debating its nature."
Tuesday, July 15, 2008
New Dwarf Planet - Makemake
We have a new 'official' fourth dwarf planet, discovered by Cal Tech's Dr. Mike Brown three years ago, the Kuiper Belt Object and plutoid formerly known as 2005 FY9 has been designated Makemake (prenounced makimaki), the creator god of Easter Island mythology. It is the third largest trans-Neptunian object yet discovered after Eris, also discovered by Brown, (the event which led to the new 'dwarf planet classification) and Pluto itself.
"This object was discovered by Mike Brown, Chad Trujillo and David Rainowitz on March 31, 2005, just before Easter that year. They nicknamed it Easterbunny (which is easier to say than 2005 FY9 or 136472) and after tossing a few different names around, they finally came up with Makemake because of its Easter Island, (also known as Rapa Nui) connection.
Makemake is the creator of humanity and the god of fertility in the mythology of the South Pacific island of Rapa Nui. He was the chief god of the Tangata manu bird-man cult and was worshipped in the form of sea birds, which were his incarnation. His material symbol, a man with a bird's head, can be found carved in petroglyphs on the island."
"This object was discovered by Mike Brown, Chad Trujillo and David Rainowitz on March 31, 2005, just before Easter that year. They nicknamed it Easterbunny (which is easier to say than 2005 FY9 or 136472) and after tossing a few different names around, they finally came up with Makemake because of its Easter Island, (also known as Rapa Nui) connection.
Makemake is the creator of humanity and the god of fertility in the mythology of the South Pacific island of Rapa Nui. He was the chief god of the Tangata manu bird-man cult and was worshipped in the form of sea birds, which were his incarnation. His material symbol, a man with a bird's head, can be found carved in petroglyphs on the island."
Thursday, April 10, 2008
New Planet Detector should find ExoEarths
Astrobiology takes a look at new technology which should greatly aid our search for extraterrestrial earth type planets. The most successful method of finding such worlds has been the "wobble" method, where astronomers observe the gravitational 'tug' of planets of the light we receive from distant stars. In addition, there is even more difficult to detect 'transit' technique whereby the impact of a planet passing in front of the star from our vantage point lowers the amount of light reaching us from the star - obviously, timing is everything for this technique. With either method, large planets in relatively close orbits ('Hot Jupiters') are the easiest to find. Observing these large planets often lead to the discovery of others within the same system after further analysis of the gravitational effects.
However, things, as they say, they are a changin'. We are on what is likely to be the cusp of the greatest explosion of extrasolar planet finds in human history. Around 300 planets have already been detected using current methods.
" A revolutionary laser technology being developed by scientists and engineers at the Harvard-Smithsonian Center for Astrophysics (CfA), with colleagues at MIT, will enable scientists to spot Earth-sized worlds in Earth-like orbits. The technology is a major step forward in the search for habitable worlds beyond our Solar System."We are at the cusp of a new era in planet searches, said CfA astrophysicist Chih-Hao Li. "With this technology we are developing, astronomers will finally be able to find the first truly Earth-like worlds in terms of size and orbit."
The new technology is a highly precise refinement of the 'wobble' technique. Current tech can find planets as small as 5 earth masses, but only in a fairly tight orbit around an alien star. The new device, which the researchers refer to as an 'astro-comb' uses ultrashort duration laser pulses combined with an atomic clock to provide a precision instrument capable of taking accurate measurments as small as one part in a trillion. This refinement may increase the 'wobble' detection accuracy as much aa 100 times, allowing planets even smaller than Earth to be detected. The new device is expected to go live for testing at Mount Hopkins Observatory this summer, with an improved design expected to be installed in the Canary Island's New Earth Facility by 2010.
However, things, as they say, they are a changin'. We are on what is likely to be the cusp of the greatest explosion of extrasolar planet finds in human history. Around 300 planets have already been detected using current methods.
" A revolutionary laser technology being developed by scientists and engineers at the Harvard-Smithsonian Center for Astrophysics (CfA), with colleagues at MIT, will enable scientists to spot Earth-sized worlds in Earth-like orbits. The technology is a major step forward in the search for habitable worlds beyond our Solar System."We are at the cusp of a new era in planet searches, said CfA astrophysicist Chih-Hao Li. "With this technology we are developing, astronomers will finally be able to find the first truly Earth-like worlds in terms of size and orbit."
The new technology is a highly precise refinement of the 'wobble' technique. Current tech can find planets as small as 5 earth masses, but only in a fairly tight orbit around an alien star. The new device, which the researchers refer to as an 'astro-comb' uses ultrashort duration laser pulses combined with an atomic clock to provide a precision instrument capable of taking accurate measurments as small as one part in a trillion. This refinement may increase the 'wobble' detection accuracy as much aa 100 times, allowing planets even smaller than Earth to be detected. The new device is expected to go live for testing at Mount Hopkins Observatory this summer, with an improved design expected to be installed in the Canary Island's New Earth Facility by 2010.
Monday, March 10, 2008
Nearest Stellar Neighbor May Have Earth's Twin
via ScienceDaily, a new mathematical model of the formation of our nearest stellar neighbor Alpha Centauri shows a rather intriguing result - the formation of a terrestrial type planet in the habital zone of Alpha Centauri B. The system has long thought to be a likely candidate for such planets, given the relatively high heavy element content of its three stars.
"The closest stars to our Sun are in the three-star system called Alpha Centauri, a popular destination for interstellar travel in works of science fiction. UCSC graduate student Javiera Guedes used computer simulations of planet formation to show that terrestrial planets are likely to have formed around the star Alpha Centauri B and to be orbiting in the "habitable zone" where liquid water can exist on the planet's surface. The researchers then showed that such planets could be observed using a dedicated telescope."
The simulations of Alpha Centauri's formation were run numerous times by a team at the University of California Santa Clara, evolving the system up to an age of around 200 million years. Although the results differed with changing assumptions run in each model, in every case simulated a system of multiple planets with at least one Earth sized planet developed. In many of these simulations, such a terrestrial planet formed in the star's habital zone, where temperatures would allow liquid water to reside.
While the star's relatively high position in the Southern sky and brightness are positive factors in finding such a planet, the gravitational "wobble" created on the star by such a planet would be quite small, and up to five years of direct observation might be necessary in order to detect a planet with current methods. There is a team out of San Francisco State University conducting such observations.
"The closest stars to our Sun are in the three-star system called Alpha Centauri, a popular destination for interstellar travel in works of science fiction. UCSC graduate student Javiera Guedes used computer simulations of planet formation to show that terrestrial planets are likely to have formed around the star Alpha Centauri B and to be orbiting in the "habitable zone" where liquid water can exist on the planet's surface. The researchers then showed that such planets could be observed using a dedicated telescope."
The simulations of Alpha Centauri's formation were run numerous times by a team at the University of California Santa Clara, evolving the system up to an age of around 200 million years. Although the results differed with changing assumptions run in each model, in every case simulated a system of multiple planets with at least one Earth sized planet developed. In many of these simulations, such a terrestrial planet formed in the star's habital zone, where temperatures would allow liquid water to reside.
While the star's relatively high position in the Southern sky and brightness are positive factors in finding such a planet, the gravitational "wobble" created on the star by such a planet would be quite small, and up to five years of direct observation might be necessary in order to detect a planet with current methods. There is a team out of San Francisco State University conducting such observations.
Monday, February 04, 2008
Habitable Zones More Extensive
via Astrobiology, a new look at both our own world and exoplanets like those found in the Gliese system have caused researchers to expand the habitable zone found around distant stars. In effect, previous searches for planets with liquid water ignored the latitudinal variation that effects temperature so much here on Earth. Adding in effects like hydrothermal vents, volcanic activity and tidal forces, and the distance in which liquid water could range on a distant world could more than double.
"In old models of planetary conditions, average global temperatures provided approximate figures. For example, the Earth is said to have a mean global temperature of 15°C. This simplification is useful for mathematical modelling but doesn’t reflect reality. We know that some places on the Earth are much hotter and others colder. There’s also great variability in temperatures during different seasons. The latitude of continents dramatically influences temperature as well. Consider that Africa is hotter than Antarctica, even though they’re on the same planet. Professor Siegfried Franck of the Potsdam Institute realised that such variations on a planet could change our views on habitable zones.
Franck and his team devised equations to take into account temperature variations caused by the latitude of continents. They found that areas of frozen worlds could be habitable even though they are far from their parent stars. “Our result was that if we investigate this latitudinal dependence, the outer edge of the habitable zone can be extended a remarkable amount,” says Franck."
To use our own system as an example, liquid water could exist under the right conditions on a planet up to twice as distant as the Earth is from the Sun. Therefore, hardy types of biological organisms (such as extremophiles found in the Artic and Antarctic regions on Earth) could exist on frozen worlds far from their parent stars, such as the Gliese system, where a pair of large "super Earths" exist just inside the habitable zone of their star. Such organisms might hibernate for long periods until temperatures raise for brief periods in the planet's orbit or local conditions activate the creatures.
"In old models of planetary conditions, average global temperatures provided approximate figures. For example, the Earth is said to have a mean global temperature of 15°C. This simplification is useful for mathematical modelling but doesn’t reflect reality. We know that some places on the Earth are much hotter and others colder. There’s also great variability in temperatures during different seasons. The latitude of continents dramatically influences temperature as well. Consider that Africa is hotter than Antarctica, even though they’re on the same planet. Professor Siegfried Franck of the Potsdam Institute realised that such variations on a planet could change our views on habitable zones.
Franck and his team devised equations to take into account temperature variations caused by the latitude of continents. They found that areas of frozen worlds could be habitable even though they are far from their parent stars. “Our result was that if we investigate this latitudinal dependence, the outer edge of the habitable zone can be extended a remarkable amount,” says Franck."
To use our own system as an example, liquid water could exist under the right conditions on a planet up to twice as distant as the Earth is from the Sun. Therefore, hardy types of biological organisms (such as extremophiles found in the Artic and Antarctic regions on Earth) could exist on frozen worlds far from their parent stars, such as the Gliese system, where a pair of large "super Earths" exist just inside the habitable zone of their star. Such organisms might hibernate for long periods until temperatures raise for brief periods in the planet's orbit or local conditions activate the creatures.
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