Table 1
Nonfree parameters involved in the fits.
| Parameter | Units | Value | Refs. and comments |
|---|---|---|---|
| D | pc | 310 ± 17 | 1 |
| α⋆ | mas | 7.0 ± 0.4 | 2 |
| R⋆ | cm | (3.3 ± 0.4) × 1013 | |
| Ṁ | M⊙ yr−1 | (1.4 ± 0.4) × 10−7 | 3,S |
| Rii | R⋆ | 3.2 | A |
| Riii | R⋆ | 200 | A |
| TK(r) | K |  |
4 |
| Tdust(r) | K |  |
5 |
| ndust(R⋆ ≤ r < Rii) | cm−3 | 0.0 | |
| fAC(Rii ≤ r < Riii) | % | 0 | A |
| fAC(r ≥ Riii) | % | 100 | A |
| fSiC(Rii ≤ r < Riii) | % | 100 | A |
| fSiC(r ≥ Riii) | % | 0 | A |
| Δv(r ≥ Rii) | km s−1 | 1.0 ± 0.2 | 6 |
| xHe | 0.17 | 7 |
Notes. Nonfree parameters were fixed throughout the modeling process. D: distance to the star; α⋆: angular stellar radius; R⋆: linear stellar radius (inner radius of Region I); Ṁ: mass-loss rate; Rii and Riii: position of the inner boundaries of Regions II and III (Ri = 1R⋆); TK (r): gas kinetic temperature (T⋆ is a free parameter; see Table 2); Tdust: temperature of dust grains (Td0 is a free parameter; see Table 2); ndust(r): density of dust grains (∝ r−2); fX: fraction of dust grains composed of material X (AC: amorphous carbon; SiC: silicon carbide); Δv: line width; xHe: He abundance with respect to H2. Comments: A: parameter assumed after many tries, S: scaled to account for the new distance.
References. (1) Gaia EDR3 (Gaia Collaboration 2021). (2) Ragland et al. (2006). (3) Ramstedt & Olofsson (2014). (4) Guélin et al. (2018). (5) Sopka et al. (1985), p = 1. (6) Keady et al. (1988). (7) Asplund et al. (2009).
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.