New research shows that astronomers have discovered at least three small stars masquerading as exoplanets.
The three, and possibly four, stars were originally discovered by NASA kepler space telescope. At that time, they were classified as outer planets. However, a new study suggests that its original classification may be a case of misidentification, according to a permit from the Massachusetts Institute of Technology (MIT), where most researchers are based.
Scientists have reconsidered the measurements of the host planets stars To check the size of the candidate exoplanets. This revealed three suspect objects – known as Kepler-854b, Kepler-840b and Kepler-699b – that are between two and four times the size of Jupiter, which is too big to be a planet. Instead, the researchers argue, they should be classified as small stars.
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“Most of the exoplanets The size of Jupiter or much smaller. twice [the size of] Jupiter is indeed suspicious, said Prajwal Niraula, lead author of the study and a graduate student in the Department of Earth, Atmospheric and Planetary Sciences at MIT, in the statement. “It couldn’t be a planet bigger than that, which is what we found. ”
The fourth disguised star, known as Kepler-747b, is about 1.8 times the size of Jupiter, which is comparable to the largest confirmed exoplanet. However, Kepler-747b is located relatively far from its star, which means it likely won’t receive enough light to sustain itself as a planet of this size. While this does not definitively rule out Kepler 747b as a candidate exoplanet, researchers are skeptical about its existence planet classification.
“Overall, this study makes the current list of planets more complete,” Avi Shporer, co-author of the study and research scientist at MIT’s Kavli Institute for Astrophysics and Space Research, said in the statement. “People rely on this list to study the number of planets as a whole. If you are using a sample with few intruders, your results may be inaccurate. So, it is important that the list of planets is not polluted.”
The true identity of these stars has been revealed as part of a larger effort to identify signs of tidal distortion in exoplanet systems. The gravitational pull between two objects can affect the shapes of the two objects. When two objects are close to each other, the gravitational force of each will stretch the other in the shape of an egg or an ellipsoid.
The amount of distortion is determined by the mass of the accompanying object. Therefore, researchers can determine if they are looking at a file binary star system Or a star-planet system based on the strength of the tides observed, according to the statement.
And when the scientists looked at the latest data on Kepler-854b, the researchers found an elliptical signal too big to be caused by a planet. Since the sizes of exoplanets are estimated based on their comparison to the size of the star they orbit, the scientists decided to look at data collected by the European Space Agency’s Space Star Mapping mission, Jaya.
Indeed, the Gaia data indicated that the star Kepler-854 is much larger than scientists realized when a possible exoplanet was discovered. Recalculating, the researchers determined that Kepler 854 b is three times the size of Jupiter. This indicates that Kepler-854b is a small star orbiting a larger host star, not an exoplanet.
Improved Gaia measurements have prompted researchers to recalculate the size of other suspected exoplanets orbiting stars whose size estimates have changed dramatically.
“This was a very big science,” Niraula said in the statement. “We now have three bodies that are not planets now, and the fourth is probably not a planet.”
Although scientists have identified nearly 5,000 exoplanets so far, the team does not expect to make further corrections to their existing exoplanet catalogs, according to the statement.
“This is a small correction,” said Sporer. “It comes from a better understanding of the stars, which is only getting better all the time. So, the probability that the star’s radius is incorrect is much lower. These misclassifications will not happen many times.”
The results were Posted on March 15th In the Astronomical Journal.
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