Author ORCID Identifier
Collins, Kevin https://orcid.org/0000-0003-2781-3207 Addison, Brett https://orcid.org/0000-0003-3216-0626 Reefe, Michael https://orcid.org/0000-0003-4701-8497 Plavchan, Peter https://orcid.org/0000-0002-8864-1667 Gao, Peter N-1187-2017 https://orcid.org/0000-0002-8518-9601 Lee, Rena https://orcid.org/0000-0001-7058-4134 Sanchez Bejar, Victor J. https://orcid.org/0000-0002-5086-4232 Gagne, Jonathan X-2006-2018 https://orcid.org/0000-0002-2592-9612
Document Type
Article
Publication Date
12-2021
Abstract
We present updated radial-velocity (RV) analyses of the AU Mic system. AU Mic is a young (22 Myr) early-M dwarf known to host two transiting planets-P-b similar to 8.46 days, R-b = 4.381(-0.18)(+0.18) R-circle plus, P-c similar to 18.86 days, R-c = 3.5(-0.16)(+0.16) R-circle plus. With visible RVs from Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical echelle Spectrographs (CARMENES)-VIS, CHIRON, HARPS, HIRES, MINERVA-Australis, and Tillinghast Reflector Echelle Spectrograph, as well as near-infrared (NIR) RVs from CARMENES-NIR, CSHELL, IRD, iSHELL, NIRSPEC, and SPIRou, we provide a 5 sigma upper limit to the mass of AU Mic c of M-c <= 20.13 M-circle plus and present a refined mass of AU Mic b of M-b = 20.12 (+1.72)(-1.57) M-circle plus. Used in our analyses is a new RV modeling toolkit to exploit the wavelength dependence of stellar activity present in our RVs via wavelength-dependent Gaussian processes. By obtaining near-simultaneous visible and near-infrared RVs, we also compute the temporal evolution of RV "color" and introduce a regressional method to aid in isolating Keplerian from stellar activity signals when modeling RVs in future works. Using a multiwavelength Gaussian process model, we demonstrate the ability to recover injected planets at 5a significance with semi-amplitudes down to approximate to 10 m s(-1) with a known ephemeris, more than an order of magnitude below the stellar activity amplitude. However, we find that the accuracy of the recovered semi-amplitudes is similar to 50% for such signals with our model.
Publication Source (Journal or Book title)
ASTRONOMICAL JOURNAL
Recommended Citation
Cale, B., Reefe, M., Plavchan, P., Tanner, A., Gaidos, E., Gagne, J., Gao, P., Kane, S. R., Bejar, V. J., Lodieu, N., Anglada-Escude, G., Ribas, I., Palle, E., Quirrenbach, A., Amado, P., Reiners, A., Caballero, J. A., Osorio, M., Dreizler, S., Howard, A. W., Fulton, B. J., Wang, S., Collins, K. I., El Mufti, M., Wittrock, J., Gilbert, E. A., Barclay, T., Klein, B., Martioli, E., Wittenmyer, R., Wright, D., Addison, B., Hirano, T., Tamura, M., Kotani, T., Narita, N., Vermilion, D., Lee, R. A., Geneser, C., Teske, J., Quinn, S. N., Latham, D. W., Esquerdo, G. A., Calkins, M. L., Berlind, P., Zohrabi, F., Stibbards, C., Kotnana, S., Jenkins, J., Twicken, J. D., Henze, C., Kidwell, Jr., R., Burke, C., Villasenor, J., & Boyd, P. (2021). Diving Beneath the Sea of Stellar Activity: Chromatic Radial Velocities of the Young AU Mic Planetary System. ASTRONOMICAL JOURNAL, 162 (6) https://doi.org/10.3847/1538-3881/ac2c80