{"id":8985,"date":"2014-10-09T16:35:33","date_gmt":"2014-10-09T20:35:33","guid":{"rendered":"http:\/\/hobbyspace.com\/Blog\/?p=8985"},"modified":"2014-10-09T16:35:33","modified_gmt":"2014-10-09T20:35:33","slug":"the-weather-on-neptune-sized-hat-p-11b-exoplanet-weathermap-of-exoplanet-wasp-43b","status":"publish","type":"post","link":"https:\/\/hobbyspace.com\/Blog\/?p=8985","title":{"rendered":"The weather on Neptune-sized HAT-P-11b exoplanet + Weathermap of exoplanet WASP-43b"},"content":{"rendered":"

John Batchelor and David Livingston spoke yesterday with\u00a0 Dr. Heather Knutson about\u00a0Exoplanet HAT-P-11b:\u00a0The John Batchelor Show Hotel Mars, Wednesday, 10-8-14 –\u00a0Thespaceshow’s Blog<\/a><\/p>\n

The exoplanet\u00a0has been found to have<\/p>\n

clear skies and water vapor in its atmosphere. Dr. Knutson explained how clear skies and atmospheric water vapor [were]\u00a0confirmed, what it means for this specific Neptune size exoplanet and what it means for our planet searches in general.\u00a0 We talked about it having a hot atmosphere, a core but not a solid surface.\u00a0 The exoplanet is not habitable.\u00a0 HAT-P-11b is 120 light years from Earth.\u00a0 Dr. Knutson also explained why so many exoplanets have a cloudy atmosphere and why that limits our research into the exoplanet.<\/em><\/p>\n

Listen to the show:<\/p>\nhttp:\/\/archived.thespaceshow.com\/shows\/2332-BWB-2014-10-08.mp3<\/a><\/audio>\n

====<\/p>\n

And here is an announcement today from the ESA Hubble Telescope group about measurements of the atmosphere of another exoplanet:<\/p>\n

Hubble reveals most detailed exoplanet weather map ever<\/a><\/strong><\/p>\n

A team of scientists using the NASA\/ESA Hubble Space Telescope have made the most detailed map ever of the temperature of an exoplanet\u2019s atmosphere, and traced the amount of water it contains. The planet targeted for both of the investigations was the hot-Jupiter exoplanet WASP-43b.<\/p>\n

WASP-43b<\/a> is a planet the size of Jupiter<\/a> but with double the mass and an orbit much closer to its parent star than any planet in the Solar System. It has one of the shortest years ever measured for an exoplanet of its size \u2014 lasting just 19 hours.<\/p>\n

A team of astronomers working on two companion studies have now created detailed weather maps of WASP-43b. One study mapped the temperature at different layers in the planet\u2019s atmosphere, and the other traced the amount and distribution of water vapour within it \u2014 detail is shown in the video<\/a> created by the team.<\/p>\n

\u201cOur observations are the first of their kind in terms of providing a two-dimensional map of the planet\u2019s thermal structure,\u201d<\/em> said Kevin Stevenson from University of Chicago, USA, lead author of the thermal map study. \u201cThese maps can be used to constrain circulation models that predict how heat is transported from an exoplanet’s hot day side to its cool night side.\u201d<\/em><\/p>\n

The planet has different sides for day and night because it is tidally locked, meaning that it keeps one hemisphere facing the star, just as the Moon keeps one face toward Earth. The Hubble observations show that the exoplanet has winds that howl at thespeed of sound<\/a> from a day side that is hot enough to melt iron \u2014 soaring above 1500 degrees Celsius \u2014 to the pitch-black night side that sees temperatures plunge to a comparatively cool 500 degrees Celsius.<\/p>\n

To study the atmosphere of WASP-43b the team combined two previous methods of analysing exoplanets for the first time.<\/p>\n

By looking at how the parent star\u2019s light filtered through the planet\u2019s atmosphere \u2014 a technique called transmission spectroscopy<\/a> \u2014 they determined the water abundance of the atmosphere on the boundary between the day and night hemispheres.<\/p>\n

In order to make the map more detailed the team also measured the water abundances and temperatures at different longitudes. To do this they took advantage of the precision and stability of Hubble\u2019s instruments to subtract more than 99.95% of the light from the parent star, allowing them to study the light coming from the planet itself \u2014 a technique called emission spectroscopy<\/a>. By doing this at different points of the planet\u2019s orbit around the parent star they could map the atmosphere across its longitude.<\/p>\n

\"Exoplanet<\/a><\/p>\n

\n

In this artist\u2019s illustration the Jupiter-sized planet WASP-43b orbits its parent star in one of the closest orbits ever measured for an exoplanet of its size \u2014 with a year lasting just 19 hours.<\/em><\/p>\n

The planet is tidally locked, meaning it keeps one hemisphere facing the star, just as the Moon keeps one face toward Earth.<\/em><\/p>\n

The colour scale on the planet represents the temperature across its atmosphere. This is based on data from a recent study that mapped the temperature of WASP-43b in more detail than has been done for any other exoplanet.<\/em><\/p>\n

\u201cWe have been able to observe three complete rotations \u2014 three years for this distant planet \u2014 during a span of just four days,\u201d<\/em> explained Jacob Bean from the University of Chicago, USA, leader of the research project. \u201cThis was essential in allowing us to create the first full temperature map for an exoplanet and to probe its atmosphere to find out which elements it held and where.\u201d<\/em><\/p>\n

Finding the proportions of the different elements in planetary atmospheres provides vital clues to understanding how planets formed.<\/p>\n

\u201cBecause there\u2019s no planet with these tortured conditions in the Solar System, characterising the atmosphere of such a bizarre world provides a unique laboratory with which to acquire a better understanding of planet formation and planetary physics,\u201d<\/em> said Nikku Madhusudhan of Cambridge University, UK, co-author of both studies. \u201cIn this case the discovery fits well with pre-existing models of how such planets behave.\u201d<\/em><\/p>\n

The team found that WASP-43b reflected very little of its host star\u2019s light. An atmosphere like that on Earth, with clouds that reflect most of the sunlight, is not present on WASP-43b, but the team did find water vapour in the planet\u2019s atmosphere.<\/p>\n

\u201cThe planet is so hot that all the water in its atmosphere is vapourised, rather than condensed into the icy clouds we find on Jupiter,\u201d<\/em> said team member Laura Kreidberg of the University of Chicago, lead author of the study mapping water on the planet. Kreidberg describes both results in her online video<\/a>.<\/p>\n