Detecting exoplanet transits: X-ray informations

Detecting exoplanet transits at X-ray wavelengths would provide a window into the effects of high-energy irradiation on the upper atmospheres of planets. However, stars are relatively dim in the X-ray, making exoplanet transit detections difficult with current X-ray telescopes. To date, only one exoplanet (HD 189733 b) has an X-ray transit detection. In this study, we investigate the capability of future X-ray observatories to detect more exoplanet transits, focusing on both the NewAthena Wide Field Imager instrument and the proposed Advanced X-ray Imaging Satellite (AXIS), which provide more light-collecting power than current instruments. We examined all the transiting exoplanet systems in the NASA Exoplanet Archive and gathered X-ray flux measurements or estimates for each host star. We then predicted the stellar count rates for both AXIS and NewAthena and simulated light curves, using null-hypothesis testing to identify the top 15 transiting planets ranked by potential detection significance. We also evaluate transit detection probabilities when the apparent X-ray radius is enlarged due to atmospheric escape, finding that >=five of these planetary systems may be detectable on the >4{sigma} level in this scenario. Finally, we note that the assumed host star coronal temperature, which affects the shape of an X-ray transit, can also significantly affect our ability to detect the planet.

Cone search capability for table J/AJ/168/177/table1 (X-ray information and sources table)

Identifier
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/AJ/168/177
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/168/177
Related Identifier https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/168/177
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/AJ/168/177
Provenance
Creator Cilley R.; King G.W.; Corrales L.
Publisher CDS
Publication Year 2025
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Cosmology; Exoplanet Astronomy; Natural Sciences; Observational Astronomy; Physics