‘998-lights-years away’: NASA’s TESS discovers exoplanet with unusual orbit undergoing transformation

Produced by: Tarun Mishra Designed by: Manoj Kumar

Astronomical Discovery

An exoplanet, designated TIC 241249530 b, located approximately 998 light-years from Earth, is exhibiting one of the most unusual orbits ever observed and is transitioning into a “hot Jupiter” world.

Detection and Initial Findings

Discovered by NASA’s Transiting Exoplanet Survey Satellite (TESS) in January 2020, TIC 241249530 b was identified when it transited across its parent star, TIC 241249530. The planet orbits its star at a distance of about 12% of the Earth-Sun distance, completing an orbit in just 15.2 Earth days.

Orbital Characteristics

The planet’s orbit is notably eccentric, with an eccentricity of 0.94, making it one of the most elongated orbits found among exoplanets detected via the transit method. This orbit contrasts with the more circular orbits typical of most planets.

Retrograde Motion

TIC 241249530 b also exhibits retrograde motion, meaning it orbits its star in the opposite direction of the star’s rotation. This characteristic is rare among exoplanets and is seen in only two planets in our solar system: Venus and Uranus.

Migration Process

Hot Jupiters are known for their close orbits around their stars, completing a year in 10 Earth days or less. TIC 241249530 b is not yet a hot Jupiter but is in the early stages of migrating inward towards its star, a process that scientists have been trying to understand.

Research Methodology

A team of astronomers used the NN-EXPLORE Exoplanet and Stellar Speckle Imager (NESSI) and the NEID spectrograph on the WIYN 3.5-meter Telescope at Kitt Peak National Observatory to study TIC 241249530 b. These instruments helped refine observations by mitigating atmospheric distortion and measuring stellar shifts caused by the planet.

Planetary Mass and Temperature Variations

TIC 241249530 b has a mass about five times that of Jupiter. Its highly eccentric orbit causes significant temperature fluctuations, ranging from conditions similar to a summer day on Earth to temperatures high enough to melt lead.

Transformation Prediction

As TIC 241249530 b’s orbit gradually becomes more circular due to tidal forces from its star, it is expected to move closer to the star, leading to a hot Jupiter status. This transformation will result in an orbital period of less than 10 Earth days.

Significance and Publication

This exoplanet provides a rare observational opportunity to study the migration process of gas giants. The research, published on July 17 in the journal *Nature*, offers valuable insights into the formation of hot Jupiters and the dynamics of planetary migration.