Although NASA (NASA) has announced astronomy satellite, code-named "Kepler," the semi-retired, but it collects a lot of data is still being analyzed. "Kepler," the research team of astronomers are gathering together to explore these results. November 5, they held a press conference to announce the latest discovery: "Kepler" has discovered 833 exoplanets candidates. Up to now, the total number of potential exoplanets discovered it has more than 3500, it has reviewed the candidate target, 90% of the real in addition, the number of planets in the habitable zone has exceeded 100.
At the same time, "the US National Academy of Sciences" published an article on the research team from the University of California, Berkeley, the paper shows that over 20% of Sun-like star has a radius of at least 2 times less than the radius of the Earth planets, "Kepler" discovered planet, there are 10 surface to accept a similar situation with the Earth's surface energy star lighting.
Status Update
From the earth, a planet when it happens from the front through the central star, we can notice that the brightness of the star appears weak change regularly, "Kepler" can detect this change, so that we are aware of the planet The presence. Researchers can study light becomes law, estimate the planet's orbit, suggesting its properties, for example, it is like a small rocky planet like Earth, or giant planets like Neptune and ice from the liquid composition. The orbital period can tell us how far it is from the parent star, then you can determine how much light it receives energy, which can also indicate whether its orbit like Earth in the habitable zone whether within, as well as the presence of liquid water on its surface .
"Kepler" data is processed by the so-called "standard data pipe" (standard analysis pipeline), whereby the astronomers on planet eclipses recurring phenomenon systematically searching through the data observed in a total of 34 months will be the above analysis, the number of candidate planets has increased over 3500. Larger planets easier to detect because they can block more light, but there are still more than 600 pieces of similar size or smaller Earth-like planets to be found, which is located in the habitable zone has 104.
Of course, not every planet outside the solar system, there will be just across the line of sight from the parent star to Earth between, which means "Kepler," which can only detect a small part. Assume that the orbital plane of the planets are randomly distributed, "Kepler" team of astronomers using statistical methods to estimate 70% of main sequence stars have planets around at least one, in addition, half the number of M dwarfs (A small, common stars) may be located in the habitable zone of a planet.
Looking for a new "Earth"
These achievements are obtained through standard data analysis pipeline, but it is not satisfactory, then the University of California, Berkeley, a man named Eric Peidigula (Erik Petigura) graduate students to write their own independent analysis of the pipeline, and download the "Kepler" observation data analysis, he focuses on the "Kepler" observed the 42 000 Sun-like star, the software screens out 16 000 potential eclipse event, the next research team at Berkeley to verify these findings.
They spent a lot of days to study that 16,000 brightness curve, eventually found 603 worthy of study planets in the study data. Then they like "Kepler" as a team, using statistical methods to estimate the number of those planets orbit plane and the female star to Earth's line of sight does not coincide. They also found some changes in brightness of stars is very intense, it can not detect planetary occultation event.
When all studies were done, they came to the conclusion: about 20% of Sun-like star will have a radius of the Earth 2 times or less of the planet, more straightforward to say that 20 percent of the sun-like star It has a small rocky planets, like Earth and Venus did. They also determined that there are 10 planets surface received light energy is the earth's surface receives light of 1-4 times.
The new analysis also did not find a Sun-like star located in the habitable zone of the planet, as they orbit around the parent star is very long, which means "Kepler" the observed data, such a small number of planetary transits, therefore their signals are difficult to capture. However, like Earth-sized planets in orbit very close to its parent star distribution, the authors hope that they might extend to within the habitable zone.
A combination of the above figures, they estimate from the sun about 12 light-years away somewhere there will be a sun-like star has Earth-sized planets in. The question now is, how do we find it.
(Author: Flying midges)
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