exocast

The Exocast team return from a short hiatus to be joined on this show by Dr Jason Wang from Northwestern University in Illinois. Jason is a direct imager, and gives us a quick overview of how we are able to find and characterise planets through direct imaging, as well as discussing the Gemini Planet Imager, 51 Eridani b, KPIC, VLT’s Gravity, and the making of the well-known, jaw-dropping animation of the planetary system around HR 8799. Listen to the show to find out which planet Jason has adopted into our hall-of-fame as Exocast’s ‘Adopt-a-planet’ returns.

Do you have a question we didn’t ask? Join in the discussion in the comments below, and find us on Twitter, bluesky, and mastodon. You can also get your hands on Exocast merchandise at exocast.threadless.com

Exocast is edited by musician/composer Fergus Hall (https://www.fergushallmusic.com) and is supported by listener donations at buymeacoffee.com/exocast. We cannot make the show without your support and it is very much appreciated.

In this most excellent 100th episode of Exocast from the team we bring you the latest in exoplanet research and news.

Hannah and Andrew cover news from the TRAPPIST system. Hannah will dive into the JWST results that have come out about this very famous system of seven Earth-sized rocky planets. Two papers look to the mid-infrared to measure the light directly from the planets b and c in emission – finding that they likely do not have an atmosphere possibly stripped by their stars radiation. The first spectroscopic measurements of TRAPPIST show that the star itself is going to be the “star” of the show with stellar contamination dominating the data. But we remain optimistic! 5 more planets await their observations and there is much to learn about this small cool star.

Andrew covers a paper that discusses the feasibility of detecting some biosignatures from TRAPPIST-1 d and e using JWST. This “experimental sandbox” for astrobiology makes TRAPPIST the perfect place to start. The theoretical studies uses a climate model to ask the question: what could we see if it was there? The model looks for methane, carbon dioxide, oxygen, ozone, methyl chloride, and methyl mercaptan; with methane and carbon dioxide pair being the best combo to suggest something out of equilibrium possibly caused by life. But is the question we should be asking, is this the right system to look for life at all? – what do you think?

Hugh then takes us back to formation in a dramatic fashion with an astronomical mystery. A young star has been dimming and almost disappeared for over a year with variations in the starlight over nearly 1000 days. The question simply is: What is going on? It is almost always something to do with dust. This can be seen over different wavelengths showing the dust interacting with the light. But in this case the exciting new result is that about 3 years before the dimming happened, a bright event was seen in the system. What the team found through simulations suggest that there was a giant collision of planets in that system that created the bright event and then the debris field blocking the light. Space is really remarkable!

100 episodes is a huge milestone and as always Hugh, Hannah, and Andrew could not do this show without you! Thank you for listening.

Exocast is edited by Fergus Hall. You can help support Exocast and the team at BuyMeACoffee.com/exocast, and get yourself some Exocast merch at exocast.threadless.com

In this episode, Hannah, Hugh, and Andrew ask the question: Do all planets orbit stars? 

Even though the vast majority of planets found so far are bound to a star, there have been detections of planetary-mass objects floating alone through space. Are these planets? How do these objects form, and how can we detect them? Is it possible that these free-floating objects could be considered ‘habitable’? The exocast gang tackle these tricky topics and other nomenclature-related debate surrounding this seemingly simple but deceptively complex question.

Do you have a question we didn’t ask? Join in the discussion in the comments below, and find us on Twitter. You can also get your hands on Exocast merchandise at exocast.threadless.com

Exocast is edited by musician/composer Fergus Hall (https://www.fergushallmusic.com) and is supported by listener donations at buymeacoffee.com/exocast. Each coffee costs $4 and donations over $15 get a shout-out on the show. We cannot make the show without your support and it is very much appreciated.

Hugh, Hannah, & Andrew discuss a handful of interesting recent exoplanet papers from the past few months. We chat about the news coverage of K2-18b and the claims of biomarkers in that atmosphere, new discoveries, exciting atmospheres, and haze formation.

Hannah dives into the controversy of K2-18b and the announcement of DMS (a biomarker on Earth) detection amongst a methane dominated spectrum “Carbon-bearing Molecules in a Possible Hycean Atmosphere” by Madhusudhan et al.. The team discuss the responsibility we have as scientists to portray the statistics (in this case the lack of evidence to support the claim) to the press and how extraordinary claims require extraordinary care.

Hugh highlights a new discovery of “A close-in giant planet escapes engulfment by its star” by Hon et al.

And finally, Andrew explores “Planetary Scale Information Transmission in the Biosphere and Technosphere: Limits and Evolution” by Lingham et al.

Exocast is edited by Fergus Hall. Image credit: Artistic ilustration of planet K2-18b, its star K2-18 and the second planet K2-18. Credit: Alex Boersma

You can help support Exocast and the team at BuyMeACoffee.com/exocast, and get yourself some Exocast merch at exocast.threadless.com

In this episode Andrew, Hannah, and Hugh discuss the art and science of organising, and attending, scientific conferences, with a particular focus on the recent Exoclimes VI meeting held in Exeter, UK, organised by Hannah and others in the exoplanet community. These meetings are crucial for the dissemination and communication of new results among the community and further afield, but they can be daunting to attend, and very stressful to organise. The team share their personal experiences with conference attendence and organising and consider the changing role and format of the science conference in modern academia.

Do you have a question we didn’t ask? Join in the discussion in the comments below, and find us on Twitter. You can also get your hands on Exocast merchandise at exocast.threadless.com

Exocast is edited by musician/composer Fergus Hall (https://www.fergushallmusic.com) and is supported by listener donations at buymeacoffee.com/exocast. Each coffee costs $4 and donations over $15 get a shout-out on the show. We cannot make the show without your support and it is very much appreciated.

Hugh, Hannah, & Andrew discuss a handful of interesting recent exoplanet papers from the past few months. We chat all things Exoclimes VI held in Exeter in June 2023, new discoveries, exciting atmospheres, and haze formation.

Hugh highlights a new discovery of “A temperate Earth-sized planet [LP 791-18 d] with tidal heating transiting an M6 star” by Peterson et al.

Hannah dives into an escaping atmosphere covering “Giant Tidal Tails of Helium Escaping the Hot Jupiter HAT-P-32 b” by Zhang et al.

And finally, Andrew explores “Exoplanet Volatile Carbon Content as a Natural Pathway for Haze Formation” by Bergen et al.

Hugh, Hannah, & Andrew discuss a handful of interesting recent exoplanet papers from the past few months.

Andrew delves into technosignatures and a study which looked at whether nearby extraterrestrial civilisations could detect our current levels of radio leakage, and exactly what they might be able to learn.

Hannah condenses the most recent JWST exoplanet paper, on the nearby transiting super-Earth GJ486b. The beautiful spectra from JWST appear to show hints of water vapour, but is it in the planetary atmosphere or the activity on the surface of the star?

And finally, Hugh covers a trio of papers which all used a combination of Hipparcos & Gaia astrometry as well as high-contrast imaging from some of the world’s largest telescopes to confirm a new giant planet orbiting the young star AF Lep.

In this episode Andrew, Hannah, and Hugh reflect on where their careers and research in exoplanet science have led over the past few years as a chance to (re)introduce ourselves to new and regular listeners alike! We hope you’ll appreciate a slightly different format for this show.

Do you have a question we didn’t ask? Join in the discussion in the comments below, and find us on Twitter. You can also get your hands on Exocast merchandise at exocast.threadless.com

Exocast is edited by musician/composer Fergus Hall (https://www.fergushallmusic.com) and is supported by listener donations at buymeacoffee.com/exocast. Each coffee costs $4 and donations over $15 get a shout out on the show. We cannot make the show without your support and it is very much appreciated.