author = "Botelho, Rafael Bueno and Milone, Andr{\'e} de Castro and 
                         Mel{\'e}ndez, J. and Bedell, M. and Spina, L. and Asplund, M. and 
                         Santos, L. dos and Bean, J. L. and Ram{\'{\i}}rez, I. and Yong, 
                         D. and Dreizler, S. and Alves-Brito, A. and Galarza, J. Yana",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Universidade de 
                         S{\~a}o Paulo (USP)} and Center for Computational Astrophysics, 
                         Flatiron Institute and School of Physics and Astronomy, Monash 
                         University and {The Australian National University} and 
                         {Observatoire de l’Universite de Gen{\'e}ve} and {Department of 
                         Astronomy \& Astrophysics} and {Tacoma Community College} and 
                         {The Australian National University} and {Georg-August 
                         Universit{\'a}t G{\"o}ttingen} and {Universidade Federal do Rio 
                         Grande do Sul (UFRGS)} and {Universidade de S{\~a}o Paulo 
                title = "Thorium in solar twins: implications for habitability in rocky 
              journal = "Monthly Notices of the Royal Astronomical Society",
                 year = "2019",
               volume = "482",
               number = "2",
                pages = "1690--1700",
                month = "jan.",
             keywords = "stars: abundances – stars: fundamental parameters – stars: 
                         solar-type – Galaxy: disc – solar neighbourhood, planets and 
                         satellites: terrestrial planets.",
             abstract = "We have investigated the thorium (Th) abundance in a sample of 53 
                         thin disc solar twins covering a wide range of ages. These data 
                         provide constrains on the mantle energy budget of terrestrial 
                         planets that can be formed over the evolution of the Galaxys thin 
                         disc. We have estimated Th abundances with an average precision of 
                         0.025 dex (in both [Th/H] and [Th/Fe]) through comprehensive 
                         spectral synthesis of a Th II line present at 4019.1290 Ĺ, using 
                         very high resolution (R = 115 000) high quality HARPS spectra 
                         obtained at the ESO La Silla Observatory. We have confirmed that 
                         there is a large energy budget from Th decay for maintaining 
                         mantle convection inside potential rocky planets around solar 
                         twins, from the Galactic thin disc formation until now, because 
                         the pristine [Th/H]ZAMS is super-solar on average under a uniform 
                         dispersion of 0.056 dex (varying from +0.037 up to +0.138 dex 
                         based on linear fits against isochrone stellar age). Comparing to 
                         neodymium (Nd) and europium (Eu), two others neutron-capture 
                         elements, the stellar pristine abundance of Th follows Eu along 
                         the Galactic thin disc evolution, but it does not follow Nd, 
                         probably because neodymium has a significant contribution from the 
                         s-process (about 60 per cent).",
                  doi = "10.1093/mnras/sty2791",
                  url = "http://dx.doi.org/10.1093/mnras/sty2791",
                 issn = "0035-8711 and 1365-2966",
             language = "en",
           targetfile = "botelho_thorium.pdf",
        urlaccessdate = "23 nov. 2020"