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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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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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New paper: Discovery of three (plus one) small planets around a small star ?>

New paper: Discovery of three (plus one) small planets around a small star

Happy to report that we have discovered three small planets, plus one additional candidate planet, around a small cool star. This is some very nice work by my PhD student Rob Wells. The planets were discovered using data from the Kepler K2 space telescope. The planets are in fairly close orbits around their host star; the candidate planet, for which we need some more data to be certain it is really a planet, might be in the habitable zone of…

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Press release: Are we being watched? Tens of other worlds could spot the Solar System ?>

Press release: Are we being watched? Tens of other worlds could spot the Solar System

This is a week full of press releases: my other PhD student, Rob Wells, just published a paper in MNRAS about transit zones (places in the sky where an extraterrestrial observer could detect our solar system planets through transits). There are about 70 currently known exoplanet systems that are located in the solar system’s transit zones. None of those have any known habitable zone planets, but prospects of finding a habitable system with mutual transit visibility are good: the Kepler-K2…

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Press release: X-rays Reveal Temperament of Possible Planet-Hosting Stars ?>

Press release: X-rays Reveal Temperament of Possible Planet-Hosting Stars

My PhD student Rachel Booth has been working on X-ray data from several space telescopes and has published our findings in MNRAS recently: X-ray emission from stars quiets down with age much more dramatically than thought before (see here for more details about the paper). Now NASA has published a press release on Rachel’s research, here is the link: https://www.nasa.gov/mission_pages/chandra/news/x-rays-reveal-temperament-of-possible-planet-hosting-stars.html. Some really nice results, and hopefully we’ll be able to collect more data soon and study this in even more…

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