NGTS-39b is a planet comparable to Jupiter in size, discovered by a team of astronomers at the University of Warwick.
The parent star of the new exoplanet, NGTS-39, was observed multiple times between 2019 and 2024 with NASA’s Transiting Exoplanet Survey Satellite (TESS).
Also known as TIC-453147896, the star is believed to be around 2.2 billion years old, with an effective temperature of 6,053K and 16% bigger than our sun. The system is around 910 light-years from Earth.
The findings were corroborated by a number of telescopes
Led by Ioannis Apergis of the University of Warwick, the team of astronomers followed up on the original TESS findings, using NGTS; 12 robotic Newtownian telescopes to obtain further photometric observations of NGTS-39.
Radial velocity measurements from La Silla Observatory’s CORALIE and HARPS spectographs confirmed a planetary presence behind the TESS single transit event, the paper confirmed.
The radial velocity data suggested there is another exoplanet in the NGTS-39 system, but further data is required for confirmation.
A warm, Jupiter-like planet
The study reports that the new exoplanet travels on an eccentric orbit around NGTS-39, at a distance of 0.31 AU and completing orbit every 58.2 days. The equilibrium is estimated to be 519 k.
NGTS-39b is thought to have a radius of approximately 1.09 Jupiter radii and a mass of 1.47 Jupiter masses, yielding a density of 1.411 g/cm3.
The astronomers classified the exoplanet as a long-period warm Jupiter, assuming that the planetary composition is primarily hydrogen and helium- although it was noted that the higher density may indicate a higher heavy-element content.
NGTS-39b represents further opportunity for the study of gas giant exoplanets, particularly those on wide orbits. The exoplanet lies near the transition between molecular nitrogen and ammonia on the stellar effective temperature-planetary equilibrium temperature diagram and the study notes that this makes it a strong candidate for follow-up spectroscopic observations aimed at probing atmospheric chemistry in this temperature regime (500-850 K).
