Fundamental Stellar and Accretion-disk Parameters of the Eclipsing Algol-type Binary 2MASS J06281154+164439.3
Annotatsiya
Abstract We present a photometric and spectroscopic analysis of the long-period Algol-type eclipsing binary 2MASS J06281154+164439.3 (J0628), based on 1082days of TESS full-frame photometry and 21 LAMOST spectra. The radial-velocity modeling supports a semidetached configuration with a Roche-lobe-filling donor and a mass ratio q ≃ 0.37, adopting the TESS photometric ephemeris ( P = 21.556 days). The H α line exhibits persistent double-peaked emission whose peak separation is nearly constant (Δ V = 334.8 ± 16.2 km s −1 ) but with variable V / R , indicating a disk-dominated origin with modest nonaxisymmetry. Interpreting Δ V as Keplerian rotation implies an outer emitting radius R out ≈ 21.4 ± 2.2 R ⊙ (≈0.79 R L,1 ). To ensure physical self-consistency, we perform a joint forward modeling of the TESS light curve and a representative H α profile using ShellSpec . This unified model uses a physically consistent stream-impact hot spot at the outer edge of the accretion disk to reproduce the out-of-eclipse asymmetry, yielding global parameters of i = 62 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover> <mml:mrow> <mml:mo>.</mml:mo> </mml:mrow> <mml:mrow> <mml:mtext>°</mml:mtext> </mml:mrow> </mml:mover> </mml:math> 86, a = 57.60 R ⊙ , T eff,1 = 10,096 K, and T eff,2 = 4569 K. The joint fit firmly constrains the disk properties to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>log</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mrow> <mml:mi>ρ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">disk</mml:mi> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo> <mml:mo>−</mml:mo> <mml:mn>13.37</mml:mn> </mml:math> (cgs), T disk = 6021 K, R in = 3.48 R ⊙ , R out = 26.56 R ⊙ , and v turb = 49.7 km s −1 , confirming a stable Roche-lobe-contained Keplerian disk. J0628 is therefore a valuable laboratory for connecting precise binary parameters with phase-resolved disk diagnostics.