Chemical models developed to help limit the emission of pollutants by car engines are being used to study the atmospheres of hot exoplanets orbiting close to their stars. The results of a collaboration between French astronomers and applied combustion experts will be presented by Dr Oliva Venot and Dr Eric Hébrard at the European Week of Astronomy and Space Science (EWASS) 2018 in Liverpool.
Large planets similar to Neptune or Jupiter, orbiting 50 times closer to their star than the Earth does from the Sun, are thought to be composed of hydrogen-rich gas at temperatures between one and three thousand degrees Celsius, circulating at enormous speeds of nearly 10,000 kilometres per hour. With these extreme conditions, the interplay of various physical processes, such as vertical transport, circulation or irradiation, can drive the atmospheres of these hot exoplanets out of chemical equilibrium, resulting in deviations that are difficult to explain through standard astrophysical models and observations.
Venot, of the Laboratoire Interuniversitaire des Systèmes Atmosphériques, explains: “The philosophy of our team in solving problems is to search for and import well-tried methods from any other field whenever they exist. Back in 2012, we first noticed the overlap of temperature and pressure conditions between the atmospheres of hot Jupiters and car engines. Chemical networks developed for car engines are very robust as a result of years of intense R&D, laboratory studies and validation through comparison with numerous measurements performed under various conditions. The car models are valid for temperatures up to over 2,000 degrees Celsius and a wide range of pressures, so are relevant to the study of a large diversity of warm and hot exoplanet atmospheres.”
The project grew out of an initial collaboration between the Laboratoire d’Astrophysique de Bordeaux and the Laboratoire Réactions et Génie des Procédés in Nancy. Over the past six years, the team has developed models of the chemical composition of hot Jupiter and warm Neptune atmospheres based on one or several networks of chemical reactions. These chemical networks have been made available through an open access database and are now widely used and recognised in the international astrophysics community.
“It is an important part of our team’s philosophy to make input data and tools available to the community,” says Hébrard, of the University of Exeter.
In addition to car testing, the team has also drawn on the expertise of researchers working on particle accelerators. Data on the ability of molecules to absorb ultraviolet light have, to date, been available mainly at room temperature. Experiments at synchrotron facilities at the Laboratoire Interuniversitaire des Systèmes Atmosphériques will enable measurements to be made at temperatures relevant for exoplanet atmospheres.
“Other fields of research have an important role to play in the characterisation of the fantastic diversity of worlds in the Universe and in our understanding of their physical and chemical nature,” says Venot.
Dr Robert Massey
Royal Astronomical Society
Mob: +44 (0)7802 877 699
Ms Anita Heward
Royal Astronomical Society
Mob: +44 (0)7756 034 243
Dr Morgan Hollis
Royal Astronomical Society
Mob: +44 (0)7802 877 700
Dr Helen Klus
Royal Astronomical Society
Ms Marieke Baan
European Astronomical Society
Mob: +31 6 14 32 26 27
Image and caption
Artist’s impression showing a Jupiter-like transiting planet around a solar-like host star. Credit: ESO/L. Calçada
Notes for editors
The European Week of Astronomy and Space Science (EWASS 2018) will take place at the Arena and Conference Centre (ACC) in Liverpool from 3 - 6 April 2018. Bringing together around 1500 astronomers and space scientists, the conference is the largest professional astronomy and space science event in the UK for a decade and will see leading researchers from around the world presenting their latest work.
EWASS 2018 is a joint meeting of the European Astronomical Society and the Royal Astronomical Society. It incorporates the RAS National Astronomy Meeting (NAM), and includes the annual meeting of the UK Solar Physics (UKSP) group. The conference is principally sponsored by the Royal Astronomical Society (RAS), the Science and Technology Facilities Council (STFC) and Liverpool John Moores University (LJMU).
Liverpool John Moores University (LJMU) is one of the largest, most dynamic and forward-thinking universities in the UK, with a vibrant community of 25,000 students from over 100 countries world-wide, 2,500 staff and 250 degree courses. LJMU celebrated its 25th anniversary of becoming a university in 2017 and has launched a new five-year vision built around four key ‘pillars’ to deliver excellence in education; impactful research and scholarship; enhanced civic and global engagement; and an outstanding student experience.
The Royal Astronomical Society (RAS), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organizes scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 4000 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.
The RAS accepts papers for its journals based on the principle of peer review, in which fellow experts on the editorial boards accept the paper as worth considering. The Society issues press releases based on a similar principle, but the organisations and scientists concerned have overall responsibility for their content.
Follow the RAS on Twitter, Facebook and Instagram
The European Astronomical Society (EAS) promotes and advances astronomy in Europe. As an independent body, the EAS is able to act on matters that need to be handled at a European level on behalf of the European astronomical community. In its endeavours the EAS collaborates with affiliated national astronomical societies and also with pan-European research organisations and networks. Founded in 1990, the EAS is a society of individual members. All astronomers may join the society, irrespective of their field of research, or their country of work or origin. In addition, corporations, publishers and non-profit organisations can become organizational members of the EAS. The EAS, together with one of its affiliated societies, organises the annual European Week of Astronomy & Space Science (formerly known as JENAM) to enhance its links with national communities, to broaden connections between individual members and to promote European networks.
The Science and Technology Facilities Council (STFC) is keeping the UK at the forefront of international science and has a broad science portfolio and works with the academic and industrial communities to share its expertise in materials science, space and ground-based astronomy technologies, laser science, microelectronics, wafer scale manufacturing, particle and nuclear physics, alternative energy production, radio communications and radar.
STFC's Astronomy and Space Science programme provides support for a wide range of facilities, research groups and individuals in order to investigate some of the highest priority questions in astrophysics, cosmology and solar system science. STFC's astronomy and space science programme is delivered through grant funding for research activities, and also through support of technical activities at STFC's UK Astronomy Technology Centre and RAL Space at the Rutherford Appleton Laboratory. STFC also supports UK astronomy through the international European Southern Observatory.
Follow STFC on Twitter
STFC is part of UK Research and Innovation