New Exoplanet GJ 367b: Exoplanet smaller, denser than Earth detected with 8 hour-long year

New Exoplanet GJ 367b:  Astronomers have detected one of the smallest planets outside our solar system where a year is just 8 hours long. The new exoplanet is reportedly smaller and denser than Earth, whose surface temperature may reach 1,500 degrees Centigrade– hot enough to melt rock and metal.

The exoplanet is located 31 light-years from the Earth and takes only eight hours to orbit its star. The scorching-hot new exoplanet is just a bit larger than Mars with a diameter of just over 9,000 kilometres and just about as dense.

The discovery of the planet has been recorded in a new study that was published in the Science journal. The exoplanet is one of the lightest among the nearly 5,000 exoplanets with half the mass of Earth.

Exoplanet GJ 367b: All you need to know

• Exoplanet GJ 367 b is one of the “ultra-short period” (USP) group of exoplanets that orbit their star in less than 24 hours. The exoplanet was discovered using NASA's Transiting Exoplanet Survey Satellite (TESS). 

• The spectrum of its star was later studied from the Earth using the HARPS instrument on European Southern Observatory’s 3.6m telescope.

• The mass and radius of the exoplanet was determined using a combination of different evaluation methods with an accuracy of 14 and 7 percent respectively.

Exoplanet GJ 367b Mass- 55 percent of Earth's mass

Exoplanet GJ 367b Radius- 72 percent of Earth’s radius

• As per co-author Dr Vincent Van Eylen, the size and mass of the planet were calculated using two methods, both of which involved analysing the light of the planet's star:-

- One method was to measure the minute dip in emitted light from the star as the planet passed in front of it. This was done using data from TESS. 

- The other was to calculate the mass of the planet from the effect it had on the movement of the star. The detected motion was slight, no more than walking speed at a rate of 80cm a second.

• By determining the planet's radius and mass, the researchers were also able to draw conclusions about the exoplanet’s inner structure. 

• The exoplanet is reportedly a low-mass rocky planet with a higher density than the Earth. The high density indicates that the planet has an iron core.

• The properties of the exoplanet are similar to those of Mercury, which also has a disproportionately large iron and nickel core.

• However, the extreme proximity of the planet to its star means that it is exposed to an extremely high level of radiation, over 500 times stronger than what the Earth experiences. 

• The planet's surface temperature reportedly can reach up to 1500 degrees Celsius, a temperature capable of melting all rocks and metals.

Significance

As per the research team, the discovery is a step forward in their search for a “second Earth”.  The study shows that astronomers can determine the properties of even very small planets. The study, led by astronomers at the Institute of Planetary Research at the German Aerospace Center, involved 78 researchers.