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Author: ktj

Personal: some travel cancellations. ?>

Personal: some travel cancellations.

Unfortunately I have to cancel several research trips and conferences this spring and summer. I’ve recently come down with pneumonia (quite unexpectedly! with hospital stay and all) and full recovery is expected to take several months. I had planned to go to the Radio Habitability Conference in California and The X-ray Universe in Rome, for both of which I’m on the scientific organizing committee, but I won’t be able to go to those. I’ll also have to cancel several invited…

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Public lecture on exoplanets ?>

Public lecture on exoplanets

I’m giving a public lecture “Exotic worlds: planets in other solar systems and what they might look like” in the lecture series of the Irish Astronomy Association (IAA) on March 1st 2017. The location is the Bell Lecture Theatre at Queen’s University Belfast, 7pm. There will be biscuits and tea afterwards. Here’s a synopsis of the talk from the IAA: Dr Poppenhaeger will talk about how astronomers discover planets in other solar systems, and show a few of the most…

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New paper on magnetic cycle simulation of Proxima Centauri ?>

New paper on magnetic cycle simulation of Proxima Centauri

The recent discovery of an Earth-like exoplanet around Proxima Centauri has shined a spot light on slowly rotating fully convective M-stars. When such stars rotate rapidly (period <20 days), they are known to generate very high levels of activity that is powered by a magnetic field much stronger than the solar magnetic field. Recent theoretical efforts are beginning to understand the dynamo process that generates such strong magnetic fields. However, the observational and theoretical landscape remains relatively uncharted for fully…

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New papers on the ARCUS mission ?>

New papers on the ARCUS mission

Arcus is a NASA/MIDEX mission under development in response to the anticipated 2016 call for proposals. It is a freeflying, soft X-ray grating spectrometer with the highest-ever spectral resolution in the 8-51 Å (0.24 – 1.55 keV) energy range. The Arcus bandpass includes the most sensitive tracers of diffuse million-degree gas: spectral lines from O VII and O VIII, H- and He-like lines of C, N, Ne and Mg, and unique density- and temperature-sensitive lines from Si and Fe ions….

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New paper on the disappearing disk of TYC 8241 2652 1 ?>

New paper on the disappearing disk of TYC 8241 2652 1

TYC 8241 2652 1 is a young star that showed a strong mid-infrared (mid-IR, 8-25 mu) excess in all observations before 2008 consistent with a dusty disk. Between 2008 and 2010 the mid-IR luminosity of this system dropped dramatically by at least a factor of 30 suggesting a loss of dust mass of an order of magnitude or more. We aim to constrain possible models including removal of disk material by stellar activity processes, the presence of a binary companion,…

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Exoplanets conference in Bonn ?>

Exoplanets conference in Bonn

This week I am in Bonn, Germany, to give an invited talk entitled “Interactions between exoplanets and their host stars” at the conference Exoplanets – Bridging the gap between theory and observations. The conference takes place at the beautiful historical Physikzentrum in Bad Honnef. Lots of interesting talks and posters, from planet definitions (and how we should change them) to upcoming observational missions and planet formation theory. Plenty of time for discussion with all participants!

New paper on geodynamo simulations ?>

New paper on geodynamo simulations

Earth sustains its magnetic field by a dynamo process driven by convection in the liquid outer core. Geodynamo simulations have been successful in reproducing many observed properties of the geomagnetic field. However, while theoretical considerations suggest that flow in the core is governed by a balance between Lorentz force, rotational force and buoyancy (called MAC balance for Magnetic, Archimedean, Coriolis) with only minute roles for viscous and inertial forces, dynamo simulations must employ viscosity values that are many orders of…

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TEDx talk about exoplanets in habitable zones ?>

TEDx talk about exoplanets in habitable zones

Last Saturday I was honored to be an invited speaker at the TEDx conference in Klagenfurt, Austria. I spoke about exoplanets in habitable zones, and how those may compare to what we know from our own solar system. It was an extremely interesting conference – other speakers included Mateja Jamnik from the University of Cambridge who talked about her work in artificial intelligence, Guy Standing from the University of London who discussed unconditional basic income and how it can change…

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Cool Stars 19 conference review ?>

Cool Stars 19 conference review

One of my favourite conferences, the Cool Stars Workshop, took place in Uppsala last week. My PhD student Rachel Booth presented her work in a talk at the splinter session on Stellar Magnetic Activity – her first talk at a conference! And she did great! A lot of interesting stuff is going on at the moment with the spin-down and decrease in magnetic activity of old cool stars, and it seems like there may be different trends of rotation with…

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Otto-Hahn-Medal awarded to Rakesh Yadav ?>

Otto-Hahn-Medal awarded to Rakesh Yadav

Great news: my former postdoc and ongoing collaborator Dr. Rakesh Yadav was awarded the Otto-Hahn-Medal of the Max Planck Society. This is a prize the Max Planck Society awards to young scientists for outstanding achievements. Rakesh works on theoretical models of stellar and (exo-)planetary magnetic fields, with a focus on the magnetic dynamo processes in quickly rotating objects. Here’s the link to the press release. Congratulations to Rakesh!