Science & Space

Exoplanet Alert: TESS Discovered An Ultra-Short-Period Planet, HD-20329b, Orbiting A Solar-Type Star

A group of scientists discovered an ultra-short period (USP) exoplanet, HD-20329b, orbiting a G-type sun discovered by NASA's Transiting Exoplanet Survey Satellite. 

TESS is surveying approximately 200,000 of the brightest stars near the sun in search of transiting exoplanets. It has identified nearly 6,000 candidate exoplanets so far, with 268 confirmed. 

This exoplanet is part of the TOI group because it was discovered by TESS; TOI stands for "TESS Objects of Interest," therefore, its other name is TOI-4524b

The star it orbits is HD-20329, which belongs to the same group of stars as our sun, the sun is a yellow dwarf, and it is a G-type star with a surface temperature of 5596K, a luminosity of 1.12, and a steller age of almost 11 billion years, indicating that the sun is nearing the end of its life cycle. 

The sun and exoplanet were first observed using the HARPS-N spectrograph radial velocity measurement to establish the physical properties of the training exoplanet candidate discovered around HD-20329 or TOI-4524, and then the scientists used the TESS to build the detailed characteristics of the exoplanet by using the primary transit method. 

HD-20329b orbits the sun at a distance of only 0.018AU, or 1673204.5 miles or 2692761.7 kilometers. Therefore, its surface temperature is extremely high, which is around 2000K or 3140.33°F or 1726.85°C. 

The orbital period of the exoplanet is only 0.926118 days or 22.0 hours. The planet has a radius of 1.72 times that of the Earth, a mass of 7.42 times that of the Earth, and a density of 8.06 gm/cm3. The data was gathered using the radius and Doppler mass measurements method. 

HD 20329b joins about 30 USPs(Ultra Short Period) with radius and Doppler mass measurements, bringing the total number of known ultra-short-period exoplanets to about 120.