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Space scientists at the Physical Research Laboratory (PRL) in Ahmedabad have discovered a new exoplanet - a planet outside the solar system- orbiting too close to an evolved or aging star with a mass of 1.5 times that of the Sun and located 725 light years away. The discovery was done by an exoplanet search and study group of PRL lead by Prof Abhijit Chakraborthhy that included students and international collaborators from Europe and the USA, Indian Space Research Organisation (ISRO) said.
According to ISRO, the discovery was made using PRL Advanced Radial-velocity Abu-sky Search (PARAS) optical fiber-fed spectrograph, the first of its kind in India, on the 1.2 metre Telescope of PRL at its Mt Abu Observatory. Using PARAS, which has the capability to measure mass of an exoplanet, the exoplanet's mass is found to be 70 per cent and size about 1.4 times that of Jupiter.
These measurements were carried out between December 2020 and March 2021. | Photo by David Menidrey on Unsplash
These measurements were carried out between December 2020 and March 2021. Further follow-up measurements were also obtained from TCES spectrograph from Germany in April 2021, and also independent photometric observations from the PRL's 43-cm telescope at Mt. Abu, ISRO said. The star is known as HD 82139 as per the Henry Draper catalogue and TOI 1789 as per the TESS catalogue. Hence, the planet is known as TOI 1789b or HD 82139b as per the IAU nomenclature. This newly discovered star-planet system is very unique - the planet orbits the host star in just 3.2 days, thus placing it very-very close to the star at a distance of 0.05 AU (roughly one tenth the distance between Sun and Mercury). There are less than 10 such close-in systems known among the zoo of exoplanets known so far.
Owing to the close proximity of the planet to its host star, it is extremely heated with a surface temperature reaching up to 2000 K, and hence an inflated radius, making it one of the lowest density planets known (density of 0.31 gram per cc). Such close-in exoplanets around stars (with distance less than 0.1 AU) with masses between 0.25 to a few Jupiter mass are called "Hot-Jupiters".
The detection of such a system enhances our understanding of various mechanisms responsible for inflation in hot-Jupiters and the formation and evolution of planetary systems around evolving and aging stars, ISRO said. This is the second exoplanet discovered by PRL scientists using PARAS at 1.2 m Mt. Abu telescope; the first exoplanet K2-236b, a sub-Saturn size at 600 light-years away, was discovered in 2018. (IANS/ MBI)
Keywords: planet, new, scientists, discovered, mechanism, solar system, ISRO, India
Just three days into his internship, little did 17-year-old Wolf Cukier realise that he is going to make history — in helping NASA discover its first Earth-size planet resting in its star’s habitable-zone — the way our Earth rests in its Goldilocks zone.
In 2019, when Cukier finished his junior year at Scarsdale High School in New York, he joined NASA’s Goddard Space Flight Center in Greenbelt, Maryland, as a summer intern.
His job was to examine variations in star brightness captured by NASA’s Transiting Exoplanet Survey Satellite (TESS) and uploaded to the Planet Hunters TESS citizen science project.
“I was looking through the data for everything the volunteers had flagged as an eclipsing binary, a system where two stars circle around each other and from our view eclipse each other every orbit,” Cukier said.
“About three days into my internship, I saw a signal from a system called TOI 1338. At first I thought it was a stellar eclipse, but the timing was wrong. It turned out to be a planet,” he said in a NASA statement.
NASA last week announced that its Transiting Exoplanet Survey Satellite (TESS) found a planet in a habitable zone, the range of distances where conditions may be just right to allow the presence of liquid water on the surface.
“I noticed a dip, or a transit, from the TOI 1338 system, and that was the first signal of a planet,” Cukier told NBC 4 New York.
According to NASA, TOI 1338 b is 6.9 times larger than Earth and is located about 1,300 light-years away from Earth.
The planet orbits in almost exactly the same plane as the stars, so it experiences regular stellar eclipses.
A paper, which Cukier co-authored along with scientists from Goddard, San Diego State University, the University of Chicago and other institutions, has been submitted to a scientific journal.
Meanwhile, Cukier is now planning about his future in college.
“My top three choices are Princeton, MIT and Stanford,” he told News 12. (IANS)
The recently discovered cold super-Earth exoplanet orbiting around the red dwarf Barnard — the second closest star system to Earth — has the potential to harbour primitive life, says a study.
Barnard b (or GJ 699 b) is a super-Earth with a minimum of 3.2 Earth masses. It orbits its red star every 233 days near the snow-line, a distance where water freezes.
Although likely cold (-170 degrees centigrade), it could still have the potential to harbour primitive life if it has a large, hot iron or nickel core and enhanced geothermal activity, said researchers from the Villanova University in the US.
“Geothermal heating could support ‘life zones’ under its surface, akin to subsurface lakes found in Antarctica,” said Edward Guinan, Astrophysicist at the varsity.
“We note that the surface temperature on Jupiter’s icy moon Europa is similar to Barnard b but because of tidal heating, Europa probably has liquid oceans under its icy surface,” Guinan added.
The results were announced at the 233rd meeting of the American Astronomy Society (AAS) in Seattle.
Although very faint, it may be possible for Barnard b to be imaged by future very large telescopes, according to Guinan.
“Such observations will shed light on the nature of the planet’s atmosphere, surface, and potential habitability,” he said.
The most significant aspect of the discovery of Barnard’s star b is that the two nearest star systems to the Sun are now known to host planets.
Also Read- NASA Discovers Third New Planet
“This supports previous studies based on Kepler Mission data, inferring that planets can be very common throughout the galaxy, even numbering in the tens of billions,” said co-author Scott Engle from the varsity.
“Also, Barnard’s Star is about twice as old as the Sun — about nine billion years old compared to 4.6 billion years for the Sun. The universe has been producing Earth-size planets far longer than we, or even the Sun itself, have existed.” (IANS)