Rapid contraction of giant planets orbiting the 20 million-years old star V1298 Tau. (arXiv:2111.09193v2 [astro-ph.EP] UPDATED)

Rapid contraction of giant planets orbiting the 20 million-years old star V1298 Tau. (arXiv:2111.09193v2 [astro-ph.EP] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Mascareno_A/0/1/0/all/0/1">A. Suárez Mascareño</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Damasso_M/0/1/0/all/0/1">M. Damasso</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lodieu_N/0/1/0/all/0/1">N. Lodieu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sozzetti_A/0/1/0/all/0/1">A. Sozzetti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bejar_V/0/1/0/all/0/1">V. J. S. Béjar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Benatti_S/0/1/0/all/0/1">S. Benatti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Osorio_M/0/1/0/all/0/1">M. R. Zapatero Osorio</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Micela_G/0/1/0/all/0/1">G. Micela</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rebolo_R/0/1/0/all/0/1">R. Rebolo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Desidera_S/0/1/0/all/0/1">S. Desidera</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Murgas_F/0/1/0/all/0/1">F. Murgas</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Claudi_R/0/1/0/all/0/1">R. Claudi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hernandez_J/0/1/0/all/0/1">J. I. González Hernández</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Malavolta_L/0/1/0/all/0/1">L. Malavolta</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Burgo_C/0/1/0/all/0/1">C. del Burgo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+DOrazi_V/0/1/0/all/0/1">V. D'Orazi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Amado_P/0/1/0/all/0/1">P. J. Amado</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Locci_D/0/1/0/all/0/1">D. Locci</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tabernero_H/0/1/0/all/0/1">H. M. Tabernero</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marzari_F/0/1/0/all/0/1">F. Marzari</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aguado_D/0/1/0/all/0/1">D. S. Aguado</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Turrini_D/0/1/0/all/0/1">D. Turrini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Guillen_C/0/1/0/all/0/1">C. Cardona Guillén</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Toledo_Padron_B/0/1/0/all/0/1">B. Toledo-Padrón</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Maggio_A/0/1/0/all/0/1">A. Maggio</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aceituno_J/0/1/0/all/0/1">J. Aceituno</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bauer_F/0/1/0/all/0/1">F. F. Bauer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Caballero_J/0/1/0/all/0/1">J. A. Caballero</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chinchilla_P/0/1/0/all/0/1">P. Chinchilla</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Esparza_Borges_E/0/1/0/all/0/1">E. Esparza-Borges</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gonzalez_Alvarez_E/0/1/0/all/0/1">E. González-Álvarez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Granzer_T/0/1/0/all/0/1">T. Granzer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Luque_R/0/1/0/all/0/1">R. Luque</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Martin_E/0/1/0/all/0/1">E. L. Martín</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nowak_G/0/1/0/all/0/1">G. Nowak</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Oshagh_M/0/1/0/all/0/1">M. Oshagh</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Palle_E/0/1/0/all/0/1">E. Pallé</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Parviainen_H/0/1/0/all/0/1">H. Parviainen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Quirrenbach_A/0/1/0/all/0/1">A. Quirrenbach</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Reiners_A/0/1/0/all/0/1">A. Reiners</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ribas_I/0/1/0/all/0/1">I. Ribas</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Strassmeier_K/0/1/0/all/0/1">K. G. Strassmeier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Weber_M/0/1/0/all/0/1">M. Weber</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mallonn_M/0/1/0/all/0/1">M. Mallonn</a>

Current theories of planetary evolution predict that infant giant planets
have large radii and very low densities before they slowly contract to reach
their final size after about several hundred million years. These theoretical
expectations remain untested to date, despite the increasing number of
exoplanetary discoveries, as the detection and characterisation of very young
planets is extremely challenging due to the intense stellar activity of their
host stars. However, the recent discoveries of young planetary transiting
systems allow to place initial constraints on evolutionary models. With an
estimated age of 20 million years, V1298,Tau is one of the youngest solar-type
stars known to host transiting planets: it harbours a multiple system composed
of two Neptune-sized, one Saturn-sized, and one Jupiter-sized planets. Here we
report the analysis of an intense radial velocity campaign, revealing the
presence of two periodic signals compatible with the orbits of two of its
planets. We find that planet b, with an orbital period of 24 days, has a mass
of 0.64 Jupiter masses and a density similar to the giant planets of the Solar
System and other known giant exoplanets with significantly older ages. Planet
e, with an orbital period of 40 days, has a mass of 1.16 Jupiter masses and a
density larger than most giant exoplanets. This is unexpected for planets at
such a young age and suggests that some giant planets might evolve and contract
faster than anticipated, thus challenging current models of planetary
evolution.

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