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Table 2

SED model parameters.

Parameter Value
fixed

Distance 135 pc
Short-λ extinction power law α –2.0a
Long-λ extinction power law α –1.0a

Varying in faint state fit, fixed in bright state fit to faint fit

λ Extinction transition 4.0 μma
Cold dust T, L 91.3 K, 1.92 Lb
Cold dust AJ 4.2 mag b

Varying, best fit, faint state

Composite T, R, L 3514 K, 4.27 R, 2.49 L
AJ stellar extinction 9.86 mag
Hot dust T, L 562 K, 1.10 L
AJ hot dust 0 magc

Varying, best fit, bright state

Composite T, R, L 3525 K, 4.66 R, 3.01 L
AJ stellar extinction 10.1 mag
Hot dust T, L 579 K, 1.63 L
AJ hot dust 0.57 mag

Notes.

(a)

Extinction wavelength dependence adopted from Becklin et al. (1978); Mathis (1990). A transition-wavelength initial guess of 3.5 μm was used in the fit, but was allowed to float freely in the fit to the faint state photometry. The fit for the bright state photometry fixed the transition-wavelength to that of the best fit in the faint state.

(b)

When we allow the cold dust temperature and luminosity to vary in our SED fit to the bright state photometry, the effect on the best fit parameters is marginal: <1 K, <1% luminosity, ~0.1 mag AJ extinction difference. Thus, we fix these values in the bright state fit to reduce the degrees of freedom. The AJ value for the cold dust is larger than the best fit hot dust extinction, which seems counterintuitive. This may relate to non-blackbody thermal dust grain emission, or the cold and hot dust being associated with different components of the visual binary.

(c)

Negative extinction magnitudes were not allowed in the fit.

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