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Category: research

Arrival at my new institute in Potsdam ?>

Arrival at my new institute in Potsdam

I’m a tenured full professor now! I’ve started my new position, a joint professorship at the Leibniz Institute for Astrophysics Potsdam (AIP) and the University of Potsdam, this autumn. I had a very good time in Belfast, but it’s really nice to be back in my home country and have continued access to European funding, whatever will happen with Brexit. Fortunately my two PhD students in Belfast are both in their final year now, so I can supervise them from…

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Cool Stars 20 conference in Boston ?>

Cool Stars 20 conference in Boston

This summer the Cambridge Workshop on Cool Stars, Stellar Systems and the Sun had its 20th anniversary, and took place in Boston. This is my favourite conference series, and this year I was really excited because I had the honour of being an invited speaker. I gave a talk on “How planets affect cool stars”, and had a lot of good interactions with people about the science of stars and exoplanets. This was the first time I’ve given an invited…

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New paper: X-ray emission line spectra of main-sequence stars ?>

New paper: X-ray emission line spectra of main-sequence stars

We investigated the X-ray emission line spectra of cool main-sequence stars in order to construct their emission measure distributions and compare them to the Sun: “A Chandra/LETGS Survey of Main-sequence Stars” We analyze the X-ray spectra of 19 main-sequence stars observed by Chandra using its LETGS configuration. Emission measure (EM) distributions are computed based on emission line measurements, an analysis that also yields evaluations of coronal abundances. The use of newer atomic physics data results in significant changes compared to…

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XMM-Newton Conference in Madrid ?>

XMM-Newton Conference in Madrid

I was invited to give a talk on “How Stars and Planets Interact: a Look Through the High-Energy Window” at the XMM-Newton 2018 Science Workshop with a focus on X-ray time-domain astronomy. As always, had some very nice interactions with the colleagues at ESAC in Madrid. It’s interesting to hear what’s new in all the other subfields being probed by soft X-rays.

New paper: Unmasking a hot Jupiter in an unresolved binary system ?>

New paper: Unmasking a hot Jupiter in an unresolved binary system

The NGTS planet-search project in which I take part has detected a new planet in an interesting system: “Unmasking the hidden NGTS-3Ab: a hot Jupiter in an unresolved binary system” We present the discovery of NGTS-3Ab, a hot Jupiter found transiting the primary star of an unresolved binary system. We develop a joint analysis of multi-colour photometry, centroids, radial velocity (RV) cross-correlation function (CCF) profiles and their bisector inverse slopes (BIS) to disentangle this three-body system. Data from the Next…

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New paper: Kepler Object of Interest Network ?>

New paper: Kepler Object of Interest Network

I am happy to be part of the Kepler Object of Interest Network, a network of ground-based telescopes to observe transits of exoplanets discovered by the Kepler space telescope in order to figure out their masses through Transit Timing Variations. The first paper about this project is now accepted: “Kepler Object of Interest Network I. First results combining ground and space-based observations of Kepler systems with transit timing variations” During its four years of photometric observations, the Kepler space telescope…

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New paper on the Star Formation Region Serpens South ?>

New paper on the Star Formation Region Serpens South

As part of the Young Stellar Object VARiability project (YSOVAR), I am happy to report that we have published a new paper investigating the mid-infrared variability of young stellar objects in the star-forming region Serpens South. Here’s the title and abstract: “YSOVAR: Mid-infrared Variability among YSOs in the Star Formation Region Serpens South” We present a time-variability study of young stellar objects (YSOs) in the Serpens South cluster performed at 3.6 and 4.5 μm with the Spitzer Space Telescope; this…

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New paper: X-ray line coincidence photopumping in a solar flare ?>

New paper: X-ray line coincidence photopumping in a solar flare

This is somewhat unusual research for me, but it was good fun – some recent work about identifying an emission line in the X-ray regime which is excited by photons from a different atomic species which just happens to have the correct wavelength for that. This can be used as an independent density diagnostics for plasma in flaring loops, for example. The paper has just been published, here is the title and abstract: “X-ray line coincidence photopumping in a solar…

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New paper and press release: Discovery of a monster planet ?>

New paper and press release: Discovery of a monster planet

A timely discovery for Halloween: Our NGTS collaboration has discovered a “monster planet”, a giant planet around a very small star. This is very surprising, because barely any of those huge planets have been found close to tiny stars. We will have to re-think some of our planet formation theories. A neat press release has been published by Queen’s University Belfast: Monster planet discovery challenges formation theory, which gives the key points about the discovery in layperson’s terms. And here…

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New paper: Next Generation Transit Survey (2) ?>

New paper: Next Generation Transit Survey (2)

The mission paper about the Next Generation Transit Survey (NGTS), a ground-based telescope network to search for transiting exoplanets, has just been published. I’m happy to be part of this project, which is a collaboration between several universities in the UK, Germany, Chile, and Switzerland – lots of exciting discoveries to come soon! Here’s some more info about the paper: We describe the Next Generation Transit Survey (NGTS), which is a ground-based project searching for transiting exoplanets orbiting bright stars….

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