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Table 1.
Alphabetic list of recurring symbols.
| Symbol | Meaning |
|---|---|
| (a), a | Wide transparent regime |
| A | Volume absorption coefficient |
| A0 | Normalization constant for A(λ) |
| αmm | Measured spectral index at mm wavelengths (Fν) |
| αPl | Spectral index of underlying Planck function (Bν) |
| (b), b | No transparent regime |
| β | Spectral index of κ |
| βeff | Coefficient of linear fit to αmm(p) |
| βs | Spectral index of A |
| Bν | Planck function |
| Cabs | Absorption cross-section per grain |
| Cabs, total | Total, disc-integrated absorption cross-section |
| d | Distance to observer |
| Fν | Spectral flux density (per frequency interval) |
| k | Imaginary part of complex refractive index |
| κ | Mass absorption coefficient (or opacity) |
| λ | Wavelength |
| λ0 | Reference wavelength for A(λ) |
| M | Grain mass |
| Md | Total disc mass |
| n | Real part of complex refractive index |
| N | Grain number per size interval |
| N0 | Normalization constant for N(s) |
| ν | Frequency |
| (o), o | Opaque (grains) |
| p | Size distribution index |
| Δp | Vertical intercept of linear fit to p(αmm)−3 |
| Qabs | Absorption (and emission) efficiency |
| r | Distance from star to grain |
| ρ | Bulk grain density |
| (s), s | Small (grains) |
| s | Grain radius |
| s0 | Reference grain radius for N(s) |
 |
Radius for transition from small to transparent |
| sc | Radius for transition from transparent to opaque |
| (t), t | Transparent (grains) |
| T | Grain temperature |
| x | Grain size parameter |
| y | Ratio between Qabs for (t) and (s) grains |
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