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Some puzzling planets
WITH new technology and advanced methods, scientists and astronomers are discovering fascinating worlds.
Recently, a planet, ‘Super Earth’ was discovered orbiting a Sun-like star. It has 14 times the mass of Earth but is nothing like it. It has an orbit of less than ten days as compared to 365 days that our planet takes to go around the Sun. Its side that faces the Sun is probably badly scorched at something like 1,160°F, according to Portuguese researcher, Nuno Santos, who discovered this planet.
Though the new found world is not a comfortable place to visit, yet astronomers feel that it is a great achievement of technology to discover such a small world 50 light years away. Its host star mu Arae, can in a dark sky from the Southern Hemisphere.
The star harbours two more planets. A Jupiter-sized one that takes 650 days to orbit and another that lies further out. Other worlds that have been discovered with extrasolar planets are hundreds of light years away.
Alan Boss, planet formation theorist at the Carnegie Institution in Washington says, “It’s much closer to our solar system than anything else we’ve found so far.” Though Boss was not involved in the work, he believes, “This really is an exciting discovery. I’m still somewhat stunned they have such good data”. The interesting planet was found with the European Southern Observatory Telescope at La Silla, Chile.
At present, the leading theory that experts use for planet formation, works on the idea that gas giants form from a rocky core which develops over time. After that it reaches a critical point where the core’s gravity quickly collects an envelope of gas around it.
According to Santos, the newfound planet did not reach that point. “Otherwise the planet would have become much more massive,” he reasons.
According to a statement written by the European team, “This object is therefore likely to be a planet with a rocky core surrounded by a small gaseous envelope and would therefore qualify as a super-Earth.”
Santos says that life is not likely to exist on the large world but, he adds, “one never knows”.
The huge planet, having an orbit very close to its Sun-like star, is searing hot. It is also shrinking fast. Experts feel that it will probably be completely stripped off its surrounding envelope of gas with a liquid lava core left behind.
It was possible to discover this planet by detecting its extending and escaping envelope of hydrogen and other substances that trail off the surface like a comet’s.
Every second 10,000 tons of material is lost in space. The planet is actually named HD209458b and is just a mere 7 million kilometres or 4.4 million miles from its star, closer than Mercury is to our Sun. The planet completes its orbit around its star in just 3.5 days. The discovery is the first confirmed one of a basic element in the atmosphere of another world outside our solar system.
The study explains why planets are not formed closer than this to their parent star — because it is impossible to survive the heat.
Scientists feel that because of the tight orbit, huge tidal forces contribute to the loss of the atmosphere. As the planet loses its upper atmosphere, its gravitational force declines and it becomes easier for atmospheric hydrogen to escape.
With an estimated atmosphere of 18,000°F or 10,000°C, the hydrogen would be forced to expand anyway. It is also thought that this rate of the loss of the planet’s atmosphere may also be accelerating and more observations and studies will have to be made to determine the fate of the planet.
Alfred Vidal-Madjar, who led the study from the Institut d’Astrophysique de Paris, explains that “This process could become intense enough to blow off the whole atmosphere,” and leave behind “a naked solid or liquid core of about 10 times the Earth mass.”
He also says that there is a possibility that the core might be solid but there are more chances of it being liquid or lava-like. The puzzling planet was discovered initially in 1999 by noting the gravitational wobble of a planet in front of its host star.
The supposedly ‘doomed world’ is 150 light years away from us which means that what astronomers are witnessing is probably what happened 150 years ago. Its host star can be seen with binoculars in the constellation of Pegasus.
The discovery of a primeval world that is estimated to be 12.7 billion years old in the globular cluster M4, has made astronomers wonder that life might be much older than they thought.
The discovery is considered to be “mind boggling” by scientists as it might be almost as old as the Universe itself. It is much more than twice the age of Earth and other planets that have been discovered.
It is estimated to have formed when the Universe was just a billion years old and has had a pretty wild existence. Its first 10 billion years were spent around a normal star like our Sun.
The planet was then pulled in by the gravity of another star that was about to die. The ancient world was found orbiting this dying star and is almost as big as Jupiter and gaseous.
Astronomers state that since its initial existence was spent orbiting a star like our Sun, it might have had a neigbour like Earth where life might have taken hold. It was the time when our Sun was not even a tiny spark in the sky.
Steinn Sigurdsson, who led the work and is a Penn State University researcher, states that the planet was formed in an almost circular orbit between two and eight times as far from its star as Earth is from the Sun, giving an opportunity to an Earth-like terrestrial planet to form.
“This orbit is wide enough that a terrestrial planet could have comfortably fit in the habitable zone — if the terrestrial planet formed in the first place. It certainly makes it more likely that planets capable of hosting life could have formed earlier than hitherto thought. Possibly much earlier and much more commonly,” Sigurdsson states.
The Earth-like planet, if any, got destroyed amidst the gravitational chaos that later ensued. The Globular cluster M4 is 7,200 light years away in our own Milky Way Galaxy and the existence of the gas giant was first suspected in 1992.
Observations by the Hubble Space Telescope helped Sigurdsson and his team presume the intriguing journey of this planet’s life. The planet now orbits both, its own star which is now a white dwarf, and the neutron star, which is at present, rotating on its axis 100 times every second and is called a pulsar.
“We probably would never have found this planet if it had just stayed with its original star. Its history put it in the right place; the interactions helped us see it,” Sigurdsson says.
The planet has an estimated orbit of a 100 years and is the oldest known planet yet. Alan Boss, planetary formation scientist of the Carnegie Institution, finds the object’s history really puzzling. “The fact that this system managed to form a gas-giant planet 12.7 billion years ago certainly boggles the minds of those of us who are used to having a hard time going back just 4.5 billion years in time,” he says.
He further states, “If there were gas giants around at 12.7 billion years ago, I would think that there could be a few terrestrial-like planets too. Presumably some of them (would have) experienced a more gently history than this poor world and so some might have experienced some sort of flirtation with life, if not something much more serious.”
In a record-breaking discovery of the farthest known planets outside our solar system, astronomers have discovered a star and its orbiting world 17,000 light years away in the center of the Milky Way galaxy.
The planet is gaseous and is estimated to be approximately 1.5 times the mass of Jupiter. It is three times as far from its host star as Earth is from our Sun.
Though the discovery is not a surprise by itself, astronomers seem thrilled that they can now locate such far away worlds. The technique with which this is accomplished is called ‘gravitational microlensing’.
“The real strength of microlensing is its ability to detect low-mass planets,” says the leader of the study, Ian Bond, at the Institute for Astronomy in Edinburgh, Scotland.
The gravity of the newfound star and its planet is combined which acts like a lens, which then focuses the light from a more distant star at the distance of 24,000 light years away. The effect was predicted by Albert Einstein. The resulting image allows researchers to determine the presence of a planet which would not be visible with a telescope.
Dimitar Sasselov, astronomy professor and planet hunter at the Harvard-Smithsonian Centre for Astrophysics, who reviewed the new data opines, “In principle, this technique could detect a planet as small as Earth,” adding that it would take another five years to perfect the method to that level.
Microlensing is the most effective way of finding stars that are at a great distance from their stars. At distances which are comparable to Jupiter or Neptune from our Sun. It is one of the three methods used to detect extrasolar planets. The first being the wobble or Doppler method which notes the slight wobble caused on a star due to the gravitational tug of a planet. This method, although most successful can only detect stars as far as 160 light years. The other technique is the transit method, which is the detection of a planet’s shadow as it passes in front of its host star. But this method can only be successful when our vantage point is perfectly aligned to that of the planets passing.
Astronomers have succeeded in finding the youngest planet ever to have been found. Just a mere million years old. Detected by the orbiting Spitzer Space Telescope, the young world orbits a distant star.
The observatory also detected the ingredients for life 420 light years from Earth in the constellation Taurus. Water and other prebiotic chemistry in possible planet formation zones around five young stars left researchers astonished.
“We’ve seen the building blocks of habitable planets for the first time unambiguously,” said Dan Watson, professor of physics and astronomy at the University of Rochester, New York.
The orbiting observatory also spotted a stellar nursery with at least two protostars, stars underdevelopment, contain the dust and gas required to form planets. Additionally the study also indicates about 300 stars around the region to be similarly equipped.
According to experts, the discoveries lead us to believe that the formation of Earth-like planets, even life might not be as rare as previously thought.
The planet-forming envelope of dust and gas around these newborn stars are thought to be similar to the cocoon that surrounded our own solar system 4.6 billion years ago.
“By seeing what’s behind the dust, Spitzer has shown us star and planet formation is a very active process in our galaxy,” says Ed Churchwell, professor of astronomy at the University of Wisconsin, Madison.
The young star named CoKu Tau 4 shows an infrared view of a clear hole in a disk of dust around it. Theorists say that such a disk is formed when a new planet forms.
“That probably makes it the youngest planet we’ve ever seen,” says Watson.
According to Alan Boss, if the assumptions about the Spitzer observations are correct, the work has “profound implications” regarding the number of planets that might already exist.
He optimistically adds, “it may very well be that solar systems like our own are not rare in our galaxy”.
If this is true, then mankind surely stands humbled. We might not be the only intelligent critters about but just a very tiny speck in the immense and great order of Creation.
The writer
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