The European Space Agency (ESA) has discovered the brightest exoplanet yet discovered in universe . It is called LTT9779 b, it is very hot and revolves around star every 19 hours, while it is located 262 light-years from Earth.
See also: NASA's TESS: Exoplanet detected that may have water
In our night sky, the brightest objects are the moon and Venus . Venus' thick cloud layers reflect more light than Earth's cloud layers. Venus' clouds reflect 75 percent of sunlight, while Earth's clouds reflect only 30 percent . Detailed measurements made by ESA 's Cheops (CHaracterising ExOPlanet Satellite) mission show that the sparkling ball LTT9779 b reflects 80 percent of the light shining on it from its host star.
LTT9779 b was first detected in 2020 by NASA's Transiting Exoplanet Survey Satellite (TESS) and observations at the European Southern Observatory in Chile. ESA then selected the planet for further observations as part of the Cheops mission.
See also: The hot exoplanet WASP-189b looks a bit like Earth
About the same size as the planet Neptune, LTT9779 b is the largest known “mirror” in the universe. According to ESA, it is so reflective because of its metallic clouds, which are made mostly of silicate mixed with metals such as titanium. The sand and glass used to make mirrors are also made mostly of silicate. The findings are detailed in a study published July 10 in the journal Astronomy & Astrophysics.
The amount of light an object reflects is called albedo. Most planets have low albedo, mainly because they either have an atmosphere that absorbs a lot of light or their surface is rough or dark. Icy planets or those like Venus that have a reflective cloud layer tend to be exceptions.
LTT9779 b is a planet that stands out not only for its bright and cheerful appearance, but also because it shouldn't actually exist. Neptune is a planet with a "superhot" temperature due to its size, but no other planet has been found at the same greater distance from its star that has such a large size and temperature. This means that LTT9779 b is a planet located in the "hot desert of Neptune" and its atmosphere has a temperature of over 1,700 degrees.
See also: Exoplanet with black snow
Although its radius is about 4.7 times that of Earth, the length of a year on LTT9779 b is only 19 hours. All planets discovered to date that orbit their sun in less than a day fall into two categories: gas giants with a radius at least 10 times that of Earth (known as hot Jupiters) and rocky planets smaller than two Earth radii.
