An article published in the journal "Nature" reports the results of a study of the exoplanet 55 Cancri e, formally called Janssen, which confirms the presence of an atmosphere that is considered secondary, which means that it derives from emissions coming from the planet itself. A team of researchers used observations conducted with the James Webb Space Telescope to detect traces of an atmosphere.
I've seen a bunch of articles titled "Some astronomers now say #exoplanet might not have a biosignature after all" which is just wrong. ALL astronomers have been saying that. Since forever. Even the paper which published the dimethyl sulphide on K2-18b (which isn't a good biosignature btw) showed that DMS was only found in A SINGLE MODEL at a level FAR BELOW SIGNIFICANCE... ffs. One professor with an ego makes a stupid PR and the rest of us have to spend years correcting it. See also: Oumuamua.
I feel like 75% of #exoplanet astronomers get confused by planets in binary systems for some reason...
The simplest configuration is planets orbiting stars which also have a stellar companion. A large fraction of star systems are wide binaries so this is very common, and honestly not that interesting. Imagine if the Sun had an M-dwarf instead of #Planet9. Both stars could even host planets (unless the stellar companion is particularly close/large). Examples: Kepler-444, HD80606, Proxima Cen, etc
Doctoral student Björn S. Konrad from ETH Zurich joined senior planetary astronomer Franck Marchis for an engaging SETI Live on how they used remote sensing data to determine that Earth was habitable, as seen from a distance, and what the results mean for the search for life beyond Earth.
We kick off the session with Tiffany Kataria on assessing #conditions for the origin of #life on #exoplanet. For Tiffany, the origin of life is from geophysics to biophysics and important - habitable doesn’t mean inhabited and the origin of life is a way to rule out these false positives. #ExSSV
We’re back with a session on planets around white dwarfs 🪐
Ryan MacDonald reminds us that in a very long time this will be the fate of our sun too. Jupiter and Saturn will probably fine but closer in… nah likely not.
This is basically what we can test by looking at white dwarf planetary systems. Killing planets in this way means there are polluted white dwarfs with planetary material in their stellar atmosphere. But for the ones that survive we can do a study of what could be.
For the last talk of today, we’ve got Tim Cunningham on accreted planetary material determined from #xray observations.
Tim starts with the #exoplanet#HR diagram and points out polluted white dwarfs. Roughly 25-50% of the WD we know show metal pollution. This is expected to be happening when the star dies and kills its planetary system + then accretes the planetary material.
The accretion rates depend on the atmospheric models of WDs. #ExSSV
We’re back after coffee, and jump right into star-planet interaction with Babatunde Akinsanmi talking to us about the tidal deformation and atmosphere of WASP-12 b.
WASP-12 b is one of the ultra-hot Jupiter orbiting close to the Roche limit, being tidally deformed by the host star.
One can measure the tidal deformation with light curves because the shape affects the shape of the curve.
Also, the phase-curve varies! This is super cool 🥹
We are reaching the point where we need to start accounting for the influence of the host star “particles” and how they affect exoplanets. Today, we’re looking at coronal mass ejections.
Both high energy photons and particles drive planetary atmospheric escape + chemistry at lower altitudes (ionisation).
The sun is the only star we’ve detected CMEs from, so we can learn from the sun. #ExSSV
Est-on déjà en mesure de détecter des atmosphères autour de petites exoplanètes ? Nous avons fait des avancées considérables avec le télescope spatial James Webb. Elsa Ducrot fait le point sur les exoplanètes du système Trappist dans ce dernier webinaire de la Société Française d'Exobiologie.
This artist's conception shows a young, hypothetical planet around a cool star. A soupy mix of potentially life-forming chemicals can be seen pooling around the base of the jagged rocks.