Fechar
Metadados

@Article{DamineliFACDGHHJMMNRRSSW:2019:DiCiSt,
               author = "Damineli, Augusto and Fernandez-Lajus, E. and Almeida, L. A. and 
                         Corcoran, M. F. and Damineli, D. S. C. and Gull, T. R. and 
                         Hamaguchi, K. and Hillier, D. J. and Jablonski, Francisco 
                         Jos{\'e} and Madura, T. I. and Moffat, A. F. J. and Navarete, 
                         Felipe and Richardson, Noel D. and Ruiz, G. F. and Salerno, N. E. 
                         and Scalia, M. C. and Weigelt, Gerd",
          affiliation = "{Universidade de S{\~a}o Paulo (USP)} and {Universidad Nacional 
                         de La Plata} and {Universidade de S{\~a}o Paulo (USP)} and {NASA 
                         Goddard Space Flight Center} and {University of Maryland} and 
                         {NASA Goddard Space Flight Center} and {NASA Goddard Space Flight 
                         Center} and {University of Pittsburgh} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {San Jose State University} and 
                         {Universit{\'e} de Montr{\'e}al} and {Universidade de S{\~a}o 
                         Paulo (USP)} and {The University of Toledo} and {Universidade de 
                         S{\~a}o Paulo (USP)} and {Universidad Nacional de La Plata} and 
                         {Universidad Nacional de La Plata} and {Max Planck Institute for 
                         Radio Astronomy}",
                title = "Distinguishing circumstellar from stellar photometric variability 
                         in Eta Carinae",
              journal = "Monthly Notices of the Royal Astronomical Society",
                 year = "2019",
               volume = "484",
               number = "1",
                pages = "1325--1346",
                month = "Mar.",
             keywords = "binaries: general, stars: evolution, stars: individual (eta 
                         Carinae), stars: winds, outflows, dust, extinction.",
             abstract = "The interacting binary Eta Carinae remains one of the most 
                         enigmatic massive stars in our Galaxy despite over four centuries 
                         of observations. In this work, its light curve from the 
                         ultraviolet to the near-infrared is analysed using spatially 
                         resolved HST observations and intense monitoring at the La Plata 
                         Observatory, combined with previously published photometry. We 
                         have developed a method to separate the central stellar object in 
                         the ground-based images using HST photometry and applying it to 
                         the more numerous ground-based data, which supports the hypothesis 
                         that the central source is brightening faster than the 
                         almost-constant Homunculus. After detrending from long-term 
                         brightening, the light curve shows periodic orbital modulation 
                         (Delta V similar to 0.6 mag) attributed to the wind-wind collision 
                         cavity as it sweeps around the primary star and it shows variable 
                         projected area to our line-of-sight. Two quasi-periodic components 
                         with time-scales of 2-3 and 8-10 yr and low amplitude, Delta V < 
                         0.2 mag, are superimposed on the brightening light curve, being 
                         the only stellar component of variability found, which indicates 
                         minimal stellar instability. Moreover, the light-curve analysis 
                         shows no evidence of 'shell ejections' at periastron. We propose 
                         that the long-term brightening of the stellar core is due to the 
                         dissipation of a dusty clump in front of the central star, which 
                         works like a natural coronagraph. Thus, the central stars appear 
                         to be more stable than previously thought since the dominant 
                         variability originates from a changing circumstellar medium. We 
                         predict that the brightening phase, due mainly to dust 
                         dissipation, will be completed around 2032 +/- 4 yr, when the star 
                         will be brighter than in the 1600s by up to Delta V similar to 1 
                         mag.",
                  doi = "10.1093/mnras/stz067",
                  url = "http://dx.doi.org/10.1093/mnras/stz067",
                 issn = "0035-8711 and 1365-2966",
             language = "en",
           targetfile = "damineli_distinguishing.pdf",
        urlaccessdate = "05 dez. 2020"
}


Fechar