Allows Glimpse Inside Other Worlds
University of Warwick, UK | 2020 July 01
The surviving core of a gas giant has been discovered orbiting a distant star by University of Warwick astronomers, offering an unprecedented glimpse into the interior of a planet.
The core, which is the same size as Neptune in our own solar system, is believed to be a gas giant that was either stripped of its gaseous atmosphere or that failed to form one in its early life.
... the discovery ... is thought to be the first time the exposed core of a planet has been observed. It offers the unique opportunity to peer inside the interior of a planet and learn about its composition.
Located around a star much like our own approximately 730 light years away, the core, named TOI 849 b orbits so close to its host star that a year is a mere 18 hours and its surface temperature is around 1800K.
TOI 849 b was found in a survey of stars by NASA’s Transiting Exoplanet Survey Satellite (TESS), using the transit method: observing stars for the tell-tale dip in brightness that indicates that a planet has passed in front of them. It was located in the ‘Neptunian desert’ – a term used by astronomers for a region close to stars where we rarely see planets of Neptune’s mass or larger.
The object was then analysed using the HARPS instrument, on a program led by the University of Warwick, at the European Southern Observatory’s La Silla Observatory in Chile. This utilises the Doppler effect to measure the mass of exoplanets by measuring their ‘wobble’ – small movements towards and away from us that register as tiny shifts in the star’s spectrum of light. ...
First Exposed Planetary Core Discovered
University of Bern, CH | 2020 July 01
A Remnant Planetary Core in the Hot-Neptune Desert ~ David Armstrong et al
- Nature 583(7814):39 (02 July 2020) DOI: 10.1038/s41586-020-2421-7
- arXiv.org > astro-ph > arXiv:2003.10314 > 23 Mar 2020