Prof. Dpto. Física de la Tierra y Astrofísica, UCM @Fisicas_UCM @unicomplutense, @IPARCOS_UCM, @ObservaUCM cool stars & exoplanets @CARMENES_exopl, @GaiaESO
- Tweets20.4K
- Following4.8K
- Followers3.3K
- Likes28.7K
ALT This artist impression shows a planetary system with four planets circling around a star. In the foreground, a large reddish-brown rocky planet with craters is visible. Behind it, there are three smaller planets: one with blue and white colours, another with blue and brown bands, and the third with a rocky surface. In the top right corner of the image, a small but bright red star illuminates the scene, with space dust and distant stars visible in the background.
ALT This image has an artist's illustration of NASA's Transiting Exoplanet Survey Satellite (TESS) orbiting in space next to bold white text that says TESS (Transiting Exoplanet Survey Satellite). Above that text is brown text in a italic-serif font that says 1,000 Planets.
ALT We report the discovery of PALTA-1 b, a sub-Jupiter mass exoplanet candidate orbiting the nearby early-L dwarf DENIS-P J1253108-570924 (DE1253-57) located at a distance of 17 pc. The exoplanet was discovered by monitoring the L dwarf's astrometric motion with FORS2 at the Very Large Telescope over more than eight years and characterising the deviations from the expected single-source motion. The estimated planet mass is between 0.54 MJup and 0.77 MJup, depending on the uncertain mass of the ultracool dwarf host. The system's mass ratio is about 0.010, and the relative separation is estimated at 1.6-3.4 au. If confirmed, PALTA-1 b would be one of the very few known examples of a giant planet orbiting a nearby ultracool dwarf. This discovery finalises a larger astrometric planet search survey that targeted 20 nearby ultracool dwarfs and previously discovered three new ultracool binary systems.
ALT Ultracool dwarfs exhibit radio emission revealing strong magnetic fields and complex magnetospheric processes. Their auroral emission resembles that observed in magnetized Solar System planets, providing a framework to investigate their magnetic topology. We aim to characterize the magnetic activity, rotation, and atmospheric variability of the L3.5 dwarf LSPM J0036+1821 through a multiwavelength analysis. We conducted a long-term monitoring campaign combining radio observations from the Very Large Array and very long baseline interferometry arrays with TESS optical photometry, spanning 2019-2023. We analyzed time-series data to derive precise rotation periods and constructed light curves and radio dynamic spectra. The radio lightcurves were modeled using an auroral framework analogous to Jupiter's magnetosphere, incorporating main oval and active field line components. We detect persistent, compact radio emission with significant variability and high circular polarization. Periodogram
