This week we had a really nice afternoon barbecue with a bunch of people I like to call “star-planet group and friends” – i.e. my own group plus other colleagues mainly from the solar group and the MHD group. We had a lot to celebrate: my postdoc Ekaterina Ilin will start a new postdoctoral position in Groningen very soon, where she will work with Harish Vedantham on radio signatures of star-planet interactions; Prachi Rahate and Joana Wokittel have successfully defended…
My PhD student Nikoleta Ilic has investigated a really interesting object, the close M dwarf / brown dwarf pair NLTT 41135, which forms a hierarchical wide triple system with the M dwarf NLTT 41136. Nikoleta found an elevated activity of about an order of magnitude in X-rays that is most likely caused by tidal interaction between the brown dwarf and the M dwarf. Nikoleta was able to quantify this with the help of other wide M dwarf systems from the…
A good chunk of my research group plus myself spent last week in Krakow/Poland at the annual meeting of the European Astronomical Society (EAS). First time for me: we all took a “Eurocity” train that goes directly from Berlin to Krakow and takes 7 hours. Ecofriendly, and I was actually less wrung out after the train trip than I would have been after two flights (since there are no direct plane connections between Berlin and Krakow). The conference itself was…
I’m very excited these days because the first observation from my recently awarded XMM-Newton large observing program keeps getting scheduled and then re-scheduled by the XMM team. If all goes well, the first data will be collected before the end of June. The observing program is about the magnetism of old sun-like stars; specifically, my co-investigators and I want to figure out if there is still a magnetic braking mechanism operating in old stars that are rotating anomalously quickly. The…
Last week a huge delegation from my group attended the international Heraeus-Seminar “From the Heliosphere to Astrospheres – Lessons for Exoplanets and their Habitability” in Bad Honnef, Germany (conference website). We had contributed talks given by my group members Judy Chebly and Nikoleta Ilic, plus contributed talks by my group’s guests Yu Xu and Florian Rünger; posters given by Eliana Amazo-Gomez and Joana Wokittel; and three (!) invited talks by Ekaterina Ilin, Julian Alvarado-Gomez and myself. Unfortunately I became sick…
Laura Ketzer, one of my PhD students, recently published a detailed study on the fate of small exoplanets – super-Earths and mini-Neptunes – under different time evolutions of the magnetic activity of the host star. The so-called radius gap manisfests itself differently for stars that experience an early versus a late spin-down. Also in samples of mixed stellar spin-down histories the features of the gap as a whole change with age, so that uniform age samples, such as open stellar…
My PhD student Nikoleta Ilic has published a project we have been working on for the past two years: the identification of tidal star-planet interaction in a sample of planet-hosting stars. The tidal interaction leads to a spin-up of the host stars, which we identified through comparisons with co-eval companion stars in wide orbits around the star-planet systems. The paper was also featured in a joint press release of the AIP and the Harvard-Smithsonian Center for Astrophysics: https://chandra.harvard.edu/press/22_releases/press_110222.html Ilic, N….
My group is involved in two instrumentation projects that presented updates at the recent SPIE conference: the ANDES spectrograph for the ELT, where we at the AIP are responsible for the design and the construction of its UBV arm; and ARCUS, a concept for a high spectral resolution X-ray space telescope, where I am involved in the exoplanet science goals. The SPIE proceedings for both projects can be found here: Marconi et al., “ANDES, the high resolution spectrograph for the…
Two PhD students successfully defended their PhD theses after the summer break: Dr. Grace Foster completed her thesis and defense on “X-ray studies of exoplanet systems” in August 2022; Dr. Ekaterina Ilin completed her thesis and defense on “High lights: stellar flares as probes of magnetism in stars and star-planet systems” in September 2022. Congratulations! Grace has started a job as a data scientist in the US, and Ekaterina will begin a postdoc position in my group on her…
This year the Cool Stars conference – the most important conference for the stellar half of my group’s research – took place in person again, for the first time since the pandemic started. Toulouse hosted the meeting this year, and it was a really good conference, lots of new scientific insights. A pretty big delegation from my group attended: PhD students Laura Ketzer, Ekaterina Ilin, Nikoleta Ilic, Judy Chebly, and guest student Yu Xu; postdocs Eliana Amazo-Gomez and Julián Alvarado-Gomez;…