Hi all,
Please, consider attending the colloquium of Carole Haswell on the exciting topic of geology and disintegrating exoplanets.
The talk is via Zoom only as detailed below.
See also the Quid Ultra web page for additional information and past talks.
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Dear Colleagues,
we are pleased to announce that the very last colloquium of the program QUID ULTRA? Frontiers and Controversies in Astrophysics,
will be online on Thursday, April 20 2023 at 16:30 by Carole Haswell (The Open University).
Title and abstract are attached below.
The seminar will be held remotely by the speaker through the following zoom link:
https://uniroma1.zoom.us/j/811
ID riunione: 811 2290 1013
Passcode: 686688
The program QUID ULTRA? Frontiers and Controversies in Astrophysics is a series of monthly prestigious colloquia that have been run
in 2021 and 2022. This initiative has been funded by Sapienza University with the co-sponsorship of
INAF/Astronomical Observatory of Rome and of the joint PhD program in Astronomy, Astrophysics and Space Science of Sapienza,
Tor Vergata University and INAF.
Looking forward to seeing you soon,
Raffaella Schneider (on behalf of the SOC)
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April 20 2023, 16:30,
Speaker: Carole Haswell (The Open University)
Title: Towards the geology of exoplanets
Abstract:
Hot rocky exoplanets offer exciting opportunities to place terrestrial geology into Galactic context, through composition measurements with JWST and Ariel. To capitalise on these opportunities we must identify the very best targets for spectroscopic characterisation. The catastrophically disintegrating exoplanets (CDEs) are the most dramatic examples of mass loss from an ablating rocky surface. They were discovered by Kepler through the variable transits of dust co-existing with metal-rich vapour, and are particularly suitable for transmission spectroscopy because the ablated material is spread over a large scale-height. But the Kepler CDEs are too faint for transmission spectroscopy. The Dispersed Matter Planet Project (DMPP) is discovering the nearby analogues and progenitors of the Kepler CDEs. DMPP uses archival stellar spectra to identify stars we view through shrouds of diffuse, metal-rich, circumstellar gas. The underlying hypothesis is that the gas is ablated from hot, close-orbiting planets. DMPP searches for the putative planets with high-precision, high cadence radial velocity measurements. The approach has been extremely successful and efficient, with planet discoveries whenever 60 RV measurements have been collected. DMPP-1 is a compact multiplanet system orbiting a star brighter than V=8. A possible CDE transit has been discovered in TESS data. DMPP-2 b is the joint-first RV planet discovery orbiting a strongly pulsating star. DMPP-3 is an eccentric binary star system with the secondary at the mass threshold for sustaining hydrogen fusion. A 2.6 Earth mass planet orbits the K0V primary star in a 6.7 day orbit, with a second Earth-mass circumprimary planet marginally detected. DMPP-3AB is in a hitherto unpopulated parameter space for binary star planetary systems. I will include updates on our latest discoveries of around 20 short period planets, including planets orbiting a star of magnitude 6, and planets orbiting a young star. We may have caught the latter system in the act of evolving out of the Neptune desert through planetary ablation. DMPP planets are likely to be viewed edge-on as ablated material will remain concentrated near the planets’ orbital planes. Thus they have high transit probability. The subset of DMPP planets which transit are thus amenable to direct empirical determinations of mass, radius and composition.
Join Zoom Meeting
https://uniroma1.zoom.us/j/811
ID riunione: 811 2290 1013
Passcode: 686688
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