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Cool Stars 20.5 ?>

Cool Stars 20.5

Because Zenodo sometimes give a too-many-requests error during the conference, here’s a backup of my conference poster:

Paper on stellar winds blowing around our nearest exoplanet neighbour ?>

Paper on stellar winds blowing around our nearest exoplanet neighbour

A recent work led by our Schwarzschild-Fellow Dr. Julián Alvarado-Gómez shows through numerical simulations that our nearest exoplanetary neighbour experiences a space weather environment similar to our own Earth. The planet is Proxima Centauri c, a planet a few times the size of the Earth, which orbits our nearest stellar neighbour Proxima Centauri in a roughly 5-year orbit. From the abstract: A new planet has been recently discovered around Proxima Centauri. With an orbital separation of ∼1.44 au and a…

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Paper on stellar flares in open clusters ?>

Paper on stellar flares in open clusters

Ekaterina Ilin, a PhD student in my group, has recently published her work on stellar flares in three young and two middle-aged open clusters. From the abstract: “Drawing from the complete K2 archive, we searched 3435∼80 day long light curves of 2111 open cluster members for flares using the open-source software packages K2SC to remove instrumental and astrophysical variability from K2 light curves, and AltaiPony to search and characterize the flare candidates. We confirmed a total of 3844 flares on…

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Welcome to new group members ?>

Welcome to new group members

Two new group members are starting their research here in fall 2020: Judy Chebly is a new PhD student who works with Julián Alvarado-Gómez and myself on simulations of coronal mass ejections in stars-planet systems, and Dr. Eliana Amazo-Gomez is a new postdoc who works on stellar rotation and activity. We’re very happy to have them on board!

Conference: Exoplanets III ?>

Conference: Exoplanets III

This week the Exoplanets III is taking place – it has been moved from Heidelberg into a virtual format because of the Covid-19 pandemic. I’m really excited about this particular conference, because it looks like a really well thought-out way to do an online conference, with all talks being available as videos for non-synchronous viewing, interactive online posters, and active discussion on Slack. Several of our group members are presenting their work: PhD students: Laura Ketzer: Poster “Using PLATYPOS to…

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Paper on the atmospheric evaporation of four very young exoplanets ?>

Paper on the atmospheric evaporation of four very young exoplanets

Together with my PhD student Laura Ketzer and postdoc Matthias Mallonn, we have published a new paper on the atmospheric evaporation of the four very young planets around the star V1298 Tau. We measured the star’s X-ray spectrum by combining ROSAT and Chandra observations, and found that the star is highly active with an X-ray luminosity above 10^30 erg/s. Laura developed a numerical code to estimate the planetary evaporation as the star ages and becomes less X-ray bright. Depending on…

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Paper on the magnetic activity of old sunlike stars ?>

Paper on the magnetic activity of old sunlike stars

My freshly graduated PhD student, Dr. Rachel Booth, has published the final paper from her PhD thesis together with me and a few coworkers. We have analysed how the magnetic activity of sun-like stars decays as they age, and have used a sample of stars that all have well-determined asteroseismic ages. We find that even at old stellar ages on the main sequence the spin down and therefore the decay of stellar activity continues. For a read go here: “Chromospheric…

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Paper on alkali metals in an exoplanet’s atmosphere ?>

Paper on alkali metals in an exoplanet’s atmosphere

Together with my colleagues at AIP, and led by Engin Keles, a PhD student in my Star-Planet Systems group, we have published a paper on the detection of potassium in the atmosphere of a Hot Jupiter using high-resolution transmission spectroscopy. The potassium absorption on HD189733b and HD209458b, Keles, E.; Mallonn, M.; von Essen, C.; Carroll, T. A.; Alexoudi, X.; Pino, L.; Ilyin, I.; Poppenhäger, K.; Kitzmann, D.; Nascimbeni, V.; Turner, J. D.; Strassmeier, K. G. The Large Binocular Telescope (LBT)…

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White paper on X-ray interferometry ?>

White paper on X-ray interferometry

Together with many colleagues, I have contributed to a White Paper on a possible X-ray Interferometry mission. This project is led by Phil Uttley from the University of Amsterdam, and we hope to be considered for ESA’s Vision 2050 mission slot. X-ray interferometry can yield amazing spatial resolution for bright X-ray sources, even though there is still quite some technology to be developed. For stars and exoplanets, we could spatially resolve transits in front of the stellar corona – see…

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Exostar19 research program in Santa Barbara ?>

Exostar19 research program in Santa Barbara

This summer I organized a 3-month research program called Exostar19 (https://www.kitp.ucsb.edu/activities/exostar19) at the Kavli Institute for Theoretical Physics (KITP) in Santa Barbara, together with Bekki Dawson, Dan Huber, and Jim Fuller. Victor Silva Aguirre was the one who brought us all together with his idea to come up with a program that focuses on all the new insights that the stellar and planetary field can gain from TESS and Gaia data. It’s now the last week of the program, and…

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