Yeah you guessed it right. I am not allowed to share it with you Stay tuned! #ExSSV

Next up, we‘ve got Kazumasa Ohno on the hazy sub-Neptune GJ1214 b.

Previous observations show pretty flat lines, likely due to hazes and clouds. The JWST phase curve with MIRI shows a large amplitude indicative of high metallicity, but the spectrum is still consistent with a flat line. It is though predicted to have CO2 and CH4 features so they observed with #G395H. And??? #ExSSV

They looked at the c planet which is favourable with #NIRISS and find methane and hazes. Intriguingly, they don‘t find any O-bearing species. We know that water is hard to see when methane is present. But CO2 should be observable if present! Hmmm? What‘s going on?

It could be trapped in silicates in the interior. #ExSSV

Next up, we‘ve got Pierre-Alexis Roy on #JWST observations of LP791-18c revealing an atmosphere abundant methane and depleted CO2.

Already with #HST, advances were made to observe sub-Neptunes, but without much luck except for the coldest ones. #JWST has brought us a long way already though the SNR for K2-18 b is not high enough, but TOI-270 d proved better and rewrote the rules.

But what‘s in between: LP 791-18 is a system with 3 planets around an M dwarf. #ExSSV

The atm of TOI-270 d is heavy, but they don‘t find ammonia. Their GCMs reveal a well-mixed super-critical vapour envelope.

For colder planets, the story looks a bit different: more layers are added ranging from the coldest Hycean worlds to stratified mini-Neptunes.

Caroline shows us the spectrum of GJ 9827 d, dominated by water.

As of now, we reached the state that we can observe/measure the mean molecular weight + temperature transitions, where CH4 is favoured over CO. #ExSSV

The bare rock case is not possible, but for the other two they performed 3D GCMs analyses. They produced transmission spectra and find that observations should be able to discriminate between the scenarios if we can deal with stellar contamination.

#JWST comes into play with 4 transits, but I am not allowed to share it with you #ExSSV

P.S.: I realised that the speaker has actually changed. It is Charles Cadieux.

Next up, we’ve got René Doyon on LHS 1140 b: a mini-Neptune or water world?

There are two planets in this system: one super-Earth and the other one… we don‘t know?

It is located in a regime where it is likely to have an atmosphere. The planet has been observed with plenty of instruments, which they reanalysed. For planet c, this results in agreement but for b this suggests three scenarios:

Mini-neptune with rocky core + H/He envelope, water world or a bare rock? #ExSSV

Rapid rotators have a saturated flare rate, while slow rotators have very low flare rates.

Transition pairs are mostly ordered by mass. The active pairs are kinematically you g, while inactive pairs are kinematically old.

Let‘s link this to star formation: it comes in two epochs. Until ~9 Gyr ago we were forming thick disc stars and now we are forming thin disc stars.

Terrestrial are common, Jovians are not. #ExSSV

With the MEOW survey, they target around 20-30 WDs to find candidates. And they found a lot already (so maybe just contamination).

So we need to check:

The shape will give it away. Planet are not extended (galaxies are), so they need to be point sources.

The colour should be very red due to the temperature.

They identify one close-by planet, not even resolved with MIRI but follow-up is needed #ExSSV

The next talk is by Andrew Vanderburg on #MEOW: a survey targeting white dwarf systems to study the prognosis of the solar system.

Mars might survive, but be roasted. The smaller gravity after the red giant phase will push the orbits further out. See pictures for a graphics.

Combining data from TESS and JWST, they’ve found one close-in TESS planet around a WD, and even after searching 10000 more, they cannot find another one; so this is rare!

So maybe we need to look further out.

Next up, we’ve got Sydney Jenkins on thermal emission from a giant planet transiting a white dwarf.

This is basically a sibling program to the talk before but they don’t want me to share this either, so stay tuned

This planet cannot have been where it is today, so it went on a journey after the death of its star: rapid spiralling inwards or a high-eccentricity migration. But we don’t know which one happened.

This is where #JWST comes in. But little me cannot share more Stay tuned! #ExSSV

Omg what a wrap! That’s it for today See ya tomorrow #ExSSV

And this is what this looks like. The atmospheric refresh time is ~16 h, so that’s i+1. Clear —> cloudy —> clear etc.

So if you are in the unstable scenario (lower panels), you never reach the eq. state. So you don’t get the nuclear winter or the greenhouse warming, but you get both!! Damn this is cool. #ExSSV

For the last talk today, we’ve got Eugene Chiang on chaotic #winds from a dying world.

This system has a disintegrating planet with a tail behind the planet. The transit is fairly time variable - kind of on off.

A possible explanation is the limit cycle that last roughly the order of the period of the planet.

They mapped the wind from i to i+1. #ExSSV

Here are some first results for TRAPPIST-1 e. The solubility has quite an effect on the atmospheric composition #lava world people: this is for you. Include solubilities thanks.

The OH- stretching band tells us how much H2 is dissolving. More oxygen in the gas results in more H2 being dissolved. Stay tuned for more on this!

Another experiment they do is heating their sample with lasers to study emission and transmission spectra. Go labs!

Atmodeller is a volatile partitioning code between atmospheres and interiors.