Multiple metals – and possible signs of water – found in unique exoplanet

sc604 — Thu, 31 May 2018 09:39:08 +0000

̽��ֱ��team, from the ̽��ֱ�� of Cambridge and the Instituto de Astrofísica de Canarias (IAC) in Spain used the Gran Telescopio Canarias (GTC) to observe WASP-127b, a giant gaseous planet with partly clear skies and strong signatures of metals in its atmosphere. ̽��ֱ��results have been accepted for publication in the journal Astronomy & Astrophysics.

WASP-127b has a radius 1.4 times larger than Jupiter but has only 20% of its mass. Such a planet has no analogue in our solar system and is rare even within the thousands of exoplanets discovered to date. It takes just over four days to orbit its parent star and its surface temperature is around 1400 K (1127° C).

̽��ֱ��observations of WASP-127b reveal the presence of a large concentration of alkali metals in its atmosphere, allowing simultaneous detections of sodium, potassium and lithium for the first time in an exoplanet. ̽��ֱ��sodium and potassium absorptions are very broad, which is characteristic of relatively clear atmospheres. According to modelling work done by the researchers, the skies of WASP-127b are approximately 50% clear.

“ ̽��ֱ��particular characteristics of this planet allowed us to perform a detailed study of its rich atmospheric composition,” said Dr Guo Chen, a postdoctoral researcher at IAC and the study’s first author. “ ̽��ֱ��presence of lithium is important to understand the evolutionary history of the planetary system and could shed light on the mechanisms of planet formation.”

̽��ֱ��planet’s host star, WASP-127, is also lithium rich, which could point to an AGB star – a bright red giant thousands of times brighter than the sun – or a supernova having enriched the cloud of material from which this system originated.

̽��ֱ��researchers also found possible signs of water. “While this detection is not statistically significant, as water features are weak in the visible range, our data indicate that additional observations in the near-infrared should be able to detect it,” said co-author Enric Pallé, also from IAC.

̽��ֱ��results demonstrate the potential of ground-based telescopes for the study of planetary atmospheres. “ ̽��ֱ��detection of a trace element such as lithium in a planetary atmosphere is a major breakthrough and motivates new follow-up observations and detailed theoretical modelling to corroborate the findings,” said co-author Dr Nikku Madhusudhan, from Cambridge’s Institute of Astronomy.

We are just starting to probe the atmospheres of exoplanets with ground-based telescopes, but the authors believe that this will also be a reference exoplanet for future studies with space telescopes such as the James Webb Telescope, the successor to the Hubble Telescope. These future studies will reveal the detailed nature of WASP-127b as a benchmark for this new class of very low-density exoplanets.

̽��ֱ��WASP-127b observations were conducted using the OSIRIS instrument of the GTC, from the Roque de los Muchachos Observatory, in Garafía (La Palma). ̽��ֱ��Observatories of the Instituto de Astrofísica de Canarias (IAC) and the Gran Telescopio CANARIAS (GTC) are part of the Spanish Unique Scientific and Technical Infrastructures (ICTS) network.

Reference:
G. Chen et al. ‘ ̽��ֱ��GTC exoplanet transit spectroscopy survey. IX. Detection of Haze, Na, K, and Li in the super-Neptune WASP-127b.’ Astronomy & Astrophysics (in press). DOI:10.1051/0004-6361/201833033

An international team of researchers have identified ‘fingerprints’ of multiple metals in one of the least dense exoplanets ever found.

̽��ֱ��detection of a trace element such as lithium in a planetary atmosphere is a major breakthrough.

Nikku Madhusudhan

Simulación artística de WASP 127b orbitando en torno a su estrella

Instituto de Astrofísica de Canarias

Artistic simulation of WASP127b

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

̽��ֱ�� of Cambridge - Instituto de Astrofísica de Canarias

Multiple metals – and possible signs of water – found in unique exoplanet

Simulación artística de WASP 127b orbitando en torno a su estrella