2014/05/28 by I. Mendigutía, J. Fairlamb, B. Montesinos +4
Physics and Astronomy · Social Sciences · #Accretion (finance) #Astrophysics and Star Formation Studies #Balmer series #Educational Leadership and Practices #Emission spectrum #Planet #Star (game theory) #Star formation #Stellar atmosphere #Stellar evolution #Stellar mass #Stellar, planetary, and galactic studies #T Tauri star #astro-ph.SR
paper · pdf · doi:10.1088/0004-637x/790/1/21
Accepted in ApJ. 8 pages, 7 figures
arxiv created 2014/05/28 · openalex publication_date 2014/06/27 · arxiv updated 2014/07/08 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
HD 142527 is a young pre-main-sequence star with properties indicative of the presence of a giant planet and/or a low-mass stellar companion. We have analyzed an X-Shooter/Very Large Telescope spectrum to provide accurate stellar parameters and accretion rate. The analysis of the spectrum, together with constraints provided by the spectral energy distribution fitting, the distance to the star (140 ± 20 pc), and the use of evolutionary tracks and isochrones, led to the following set of parameters: T eff = 6550 ± 100 K, log g = 3.75 ± 0.10, L * / L ☉ = 16.3 ± 4.5, M * / M ☉ = 2.0 ± 0.3, and an age of 5.0 ± 1.5 Myr. This stellar age provides further constraints to the mass of the possible companion estimated by Biller et al., being between 0.20 and 0.35 M ☉ . Stellar accretion rates obtained from UV Balmer excess modeling and optical photospheric line veiling, and from the correlations with several emission lines spanning from the UV to the near-IR, are consistent with each other. The mean value from all previous tracers is 2 (±1) × 10 −7 M ☉ yr −1 , which is within the upper limit gas flow rate from the outer to the inner disk recently provided by Cassasus et al.. This suggests that almost all gas transferred between both components of the disk is not trapped by the possible planet(s) in between but fall onto the central star, although it is discussed how the gap flow rate could be larger than previously suggested. In addition, we provide evidence showing that the stellar accretion rate of HD 142527 has increased by a factor ∼7 on a timescale of 2 to 5 yr.