@Article{OtonielCoeNunMalWeb:2021:MaLiEx,
               author = "Otoniel, Edson and Coelho, Jaziel Goulart and Nunes, Silvia P. and 
                         Malheiro, Manuel and Weber, Fridolin",
          affiliation = "{Universidade Federal do Cariri (UFCA)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {Instituto Tecnol{\'o}gico de 
                         Aeron{\'a}utica (ITA)} and {Instituto Tecnol{\'o}gico de 
                         Aeron{\'a}utica (ITA)} and {San Diego State University}",
                title = "Mass limits of the extremely fast-spinning white dwarf CTCV 
                         J2056-3014",
              journal = "Astronomy and Astrophysics",
                 year = "2021",
               volume = "656",
                pages = "eA77",
                month = "Dec.",
             keywords = "Dense matter, Instabilities, Nuclear reactions, nucleosynthesis, 
                         abundances, Stars: fundamental parameters, Stars: rotation, White 
                         dwarfs.",
             abstract = "CTCV J2056-3014 is a nearby cataclysmic variable with an orbital 
                         period of approximately 1.76 h at a distance of about 853 
                         light-years from the Earth. Its recently reported X-ray properties 
                         suggest that J2056-3014 is an unusual accretion-powered 
                         intermediate polar that harbors a fast-spinning white dwarf (WD) 
                         with a spin period of 29.6 s. The low X-ray luminosity and the 
                         relatively modest accretion rate per unit area suggest that the 
                         shock is not occurring near the WD surface. It has been argued 
                         that, under these conditions, the maximum temperature of the shock 
                         cannot be directly used to determine the mass of the WD (which, 
                         under the abovementioned assumptions, would be around 0.46 Mpdbl). 
                         Here, we explore the stability of this rapidly rotating WD using a 
                         modern equation of state (EoS) that accounts for electron-ion, 
                         electron-electron, and ion-ion interactions. For this EoS, we 
                         determine the mass density thresholds for the onset of 
                         pycnonuclear fusion reactions and study the impact of microscopic 
                         stability and rapid rotation on the structure and stability of 
                         WDs, considering them with helium, carbon, oxygen, and neon. From 
                         this analysis, we obtain a minimum mass for CTCV J2056-3014 of 
                         0.56 Mpdbl and a maximum mass of around 1.38 Mpdbl. If the mass of 
                         CTCV J2056-3014 is close to the lower mass limit, its equatorial 
                         radius would be on the order of 104 km due to rapid rotation. Such 
                         a radius is significantly larger than that of a nonrotating WD of 
                         average mass (0.6 Mpdbl), which is on the order of 7 × 103 km. The 
                         effects on the minimum mass of J2056-3014 due to changes in the 
                         temperature and composition of the stellar matter were found to be 
                         negligibly small.",
                  doi = "10.1051/0004-6361/202039749",
                  url = "http://dx.doi.org/10.1051/0004-6361/202039749",
                 issn = "0004-6361 and 1432-0746",
             language = "en",
        urlaccessdate = "29 jun. 2024"
}