Pluto lost its status as a planet decades ago. But it is still the attraction for astronomers around the world. A team of astronomers recently measured atmospheric pressure on the surface by observing an occultation using the 3.6m Devasthal Optical Telescope, India’s largest optical telescope, and the 1.3m Devasthal Fast Optical Telescope (DFOT). telescope.
The telescopes are in Nainital, Uttarakhand.
The results are based on the last measured occultation in June 2020. The astronomers measured 12 such events between 1988 and 2016.
They found that the atmospheric pressure on Pluto’s surface is more than 80,000 times lower than the atmospheric pressure at Earth’s mean sea level.
In astronomy, an occultation occurs when a celestial body is hidden from view of the observer by another celestial body passing in between.
The international team of scientists included members of the Aryabhatta Research Institute of Observational Sciences (ARIES). They used signal-to-noise ratio light curves obtained with the sophisticated instruments used in the observations to derive an accurate value of Pluto’s surface atmospheric pressure.
The research published in “Astrophysical Journal Letters” showed that Pluto’s atmosphere has been in a plateau phase close to the peak since mid-2015 and is in excellent agreement with the model values previously calculated by the Pluto volatile transport model in 2019. It The team further explained that this occultation was particularly opportune because it can test the validity of current models of Pluto’s atmospheric evolution.
The study confirms previous findings that Pluto suffers from intense seasonal episodes due to a major depression known as Sputnik Planitia. Pluto’s poles remain in permanent sunlight or darkness for decades during its 248-year orbit, leading to strong effects on the nitrogen (N2) atmosphere controlled primarily by a vapor pressure equilibrium with the N2 ice at the surface.
As Pluto now moves away from the galactic plane as seen from Earth, the dwarf planet’s occultation of stars becomes increasingly rare, making this event a defining event.