exocast

On Exocast-45d we bring you the news from across exoplanet research this month with new discoveries, characterisations, habitability and formation papers.

• In America, WFIRST has been renamed the Nancy Grace Roman Space Telescope in honour to the pioneering “Mother Hubble”, while in Europe the LIFE mission kicked off.
• We have lots of new exoplanets being discovered (from TESS, NGTS, WASP and RVs), and un-discovered, as was the case for Fomalhaut b.
• Characterisation studies have also been busy this month with three papers released looking at data on the hot Jupiter WASP-76b, an unusual transmission spectrum for KELT-11b, and the He atmosphere of GJ3470b gets another look from more data.
• Formation has also been a hot topic and we look at a new paper from pioneers in the field looking to explain the formation of moons around giant planets like Jupiter.
• And in habitability we delve into a new Bayesian approach to the problem of timelines and probability for the Earth, plus a look at Venus’ habitable past.

On this episode we ask the question: Can we ever image the surface of an exoplanet?

Once we get all the definitions out of the way, like ‘what do we mean by map?’ and ‘what do we mean by surface?’, we take a deep dive into the realm of instrumentation to discuss the possibilities and limitations of our upcoming and near-future exoplanet imaging technologies.

We touch on some of the avenues that astronomers & engineers already thought about to do this, consider if it’s technologically feasible that we might be able to return images of the surface of another world, and try and understand the drivers behind why we want to do this in the first place.

In this round-up of the month’s notable exoplanetary exploits, we cover all the headlines including: Proxima c (not) being directly imaged with Sphere – WASP-4b’s accelerating orbit – two new but very different sub-Saturn-mass planets – windspeed measurements on Brown Dwarfs – plus the influence of Gin & Vampires on exoplanets (from a couple of results very early this month).

Also this month, check out our chat with Dr Sarah Casewell; and a discussion of imaging the surfaces of exoplanets.

This month Hannah, Hugh, and Andrew chat with Dr Sarah Casewell about her work on irradiated brown dwarfs. Sarah is an Earnest Rutherford Fellow at the University of Leicester where she has spent her career since undergrad. We chat all things brown dwarfs and what makes the irradiated ones so special to study.

Sarah also shares her journey in academia from PhD, to postdoc, manager, and now fellow, all while becoming a mum (twice). We also manage to grab some pearls of wisdom about what is working in academia, what is not, and how to take it easy on yourself during a global pandemic.

Adopted planet: KELT-1b a brown dwarf mascaraing as an exoplanet. At 27 times the mass of Jupiter it is solidly beyond the traditional planet mass boundary, but it also happens to be in orbit around a star only slightly larger than our sun.

In the final of three mini-exocasts we will release this month, we cover some of the notable happenings in exoplanet science over the past month.

On this episode we cover new planets from the TESS mission, a novel technique for detecting exoplanets using radio emission, and the end of the very productive KELT survey after 17 years. We also revisit K2-18b, which hit the exoplanet headlines last year after water vapour was definitively detected in its atmosphere, consider iron-based clouds, discuss the possible habitability of Mercury, and get Hannah to spill the beans on her latest paper about the use of a mode on Hubble which has not been used before to measure the UV spectrum of exoplanet atmospheres.

Also this month, check out our chat with Natalia Guerrero from the TESS office at MIT, and our discussion on the topic: ‘will we ever be able to travel to an exoplanet?‘

On this episode we ask the question: Can we EVER travel to an exoplanet?

This has two interpretations. First who is we, and second what does ever mean? To think about this question we discuss the sheer vastness of space and the distances to our nearest planets, the speeds we would need to achieve to get there, and the technology we can use. What limitations do we have, what resources can we use, and what has science fiction and the human imagination dreamt up for such an endeavour.

Join us on this fascinating journey and let us know what you think by commenting on this post.

Image credit: Kevin Gill – Laser sail

This month Hugh, Hannah, and Andrew chat with Natalia Guerrero, who works in the office of the Transiting Exoplanet Survey Satellite (TESS), which is run out of MIT’s Kavli Institute. Natalia is the manager of the TESS objects of interest (TOI) catalogue, part of the communications office, and was one of the engineers who did the camera testing prior to launch.

We talk about how TESS looks for planets, what are the biggest challenges, how she came into the project, and excitements to come. Natalia also talks about her role in TESS communications, and designing a science based concert and artwork for the TESS Science Conference last year.

Adopted planet: Pi Mensae c – the 1st planet published from TESS and sibling to Pi Men b. Pi Men c is a 2 earth-radius planet on a 6 day orbit around a bright naked eye star in the Southern Hemisphere.

Our final bite-size episode for this month features Andrew, Hannah, and Hugh chatting with Dr Stephen Kane, Associate Professor of Planetary Astrophysics in the Departments of Earth and Planetary Sciences and Physics and Astronomy at the University of California, Riverside.

Stephen tells us a little about his need to use all exoplanet detection techniques, his love for our hot and cloudy next-door neighbour Venus, and he tries to sneak two planets into our adopted exoplanet list, before settling on one special world.

In the second of three mini-casts this month, Hannah, Hugh, and Andrew gather around the virtual table to discuss that weird and wonderful molecule: H2O!

The importance of water to our lives is undeniable, but in this show we chat about what makes water so chemically unusual and important in the study of astrophysics, exoplanet astronomy, and astrobiology.

In the first of three mini-casts this month, we discuss all the recent exoplanet news from December 2019 & January 2020.

That includes a temperate world around TOI-700d; Proxima Centauri c; three new planetary systems losing their atmospheres found with RVs; Circumbinary planets in Kepler and TESS; Iron in WASP-121b; Two different phase curves from TESS; and the atmosphere of Beta Pic b in glorious detail.