Multi-band high resolution spectroscopy rules out the hot Jupiter BD+20 1790b - First data from the GIARPS Commissioning
Abstract
Context. Stellar activity is currently challenging the detection of young planets via the radial velocity (RV) technique. Aims. We attempt to definitively discriminate the nature of the RV variations for the young active K5 star BD+20 1790, for which visible (VIS) RV measurements show divergent results on the existence of a substellar companion. Methods. We compare VIS data with high precision RVs in the near infrared (NIR) range by using the GIANO - B and IGRINS spectrographs. In addition, we present for the first time simultaneous VIS-NIR observations obtained with GIARPS (GIANO - B and HARPS - N) at Telescopio Nazionale Galileo (TNG). Orbital RVs are achromatic, so the RV amplitude does not change at different wavelengths, while stellar activity induces wavelength-dependent RV variations, which are significantly reduced in the NIR range with respect to the VIS. Results. The NIR radial velocity measurements from GIANO - B and IGRINS show an average amplitude of about one quarter with respect to previously published VIS data, as expected when the RV jitter is due to stellar activity. Coeval multi-band photometry surprisingly shows larger amplitudes in the NIR range, explainable with a mixture of cool and hot spots in the same active region. Conclusions. In this work, the claimed massive planet around BD+20 1790 is ruled out by our data. We exploited the crucial role of multi- wavelength spectroscopy when observing young active stars: thanks to facilities like GIARPS that provide simultaneous observations, this method can reach its maximum potential.
Keywords
Cite
@article{arxiv.1805.01281,
title = {Multi-band high resolution spectroscopy rules out the hot Jupiter BD+20 1790b - First data from the GIARPS Commissioning},
author = {I. Carleo and S. Benatti and A. F. Lanza and R. Gratton and R. Claudi and S. Desidera and G. N. Mace and S. Messina and N. Sanna and E. Sissa and A. Ghedina and F. Ghinassi and J. Guerra and A. Harutyunyan and G. Micela and E. Molinari and E. Oliva and A. Tozzi and C. Baffa and A. Baruffolo and A. Bignamini and N. Buchschacher and M. Cecconi and R. Cosentino and M. Endl and G. Falcini and D. Fantinel and L. Fini and D. Fugazza and A. Galli and E. Giani and C. González and E. González-Álvarez and M. González and N. Hernandez and M. Hernandez Diaz and M. Iuzzolino and K. F. Kaplan and B. T. Kidder and M. Lodi and L. Malavolta and J. Maldonado and L. Origlia and H. Perez Ventura and A. Puglisi and M. Rainer and L. Riverol and C. Riverol and J. San Juan and S. Scuderi and U. Seemann and K. R. Sokal and A. Sozzetti and M. Sozzi},
journal= {arXiv preprint arXiv:1805.01281},
year = {2018}
}
Comments
12 pages, 7 figures