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SOFIA upGREAT/FIFI-LS Emission-line Observations of Betelgeuse during the Great Dimming of 2019/2020
- Source :
- The Astronomical Journal. 162:246
- Publication Year :
- 2021
- Publisher :
- American Astronomical Society, 2021.
-
Abstract
- We report NASA-DLR SOFIA upGREAT circumstellar [O i] 63.2 μm and [C ii] 157.7 μm emission profiles and FIFI-LS [O i] 63.2 μm, [O i] 145.5 μm, and [C ii] 157.7 μm fluxes obtained shortly after Betelgeuse’s 2019/2020 Great Dimming event. Haas et al. noted a potential correlation between the [O i] 63.2 μm flux and V magnitude based on three Kuiper Airborne Observatory observations made with the CGS and FIFI instruments. The FIFI observation was obtained when V ≃ 0.88 and revealed a 3σ non-detection at a quarter of the previous CGS flux measurement made when V ≃ 0.35. A potential explanation could be a change in dust-gas drag heating by circumstellar silicates caused by variations in the photospheric radiation field. SOFIA observations provide a unique test of this correlation because the V-band brightness went to its lowest value on record, V ≃ 1.61, with the SOFIA observations being made when V FIFI−LS ≃ 1.51 and V upGREAT ≃ 1.36. The upGREAT spectra show a [O i] 63.2 μm flux larger than previous space observatory measurements obtained when V ≃ 0.58. The profile is consistent with formation in the slower, more turbulent inner S1 outflow, while the [C ii] 157.7 μm profile is consistent with formation farther out in the faster S2 outflow. Modeling of dust-gas drag heating, combined with 25 yr of Wing three-filter and V photometry, reveals that it is unlikely that the S1 circumstellar envelope and [O i] 63.2 μm fluxes are dominated by the dust-gas drag heating and that another heating source is also active. The [O i] 63.2 μm profile is hard to reconcile with existing outflow velocity models.
Details
- ISSN :
- 15383881 and 00046256
- Volume :
- 162
- Database :
- OpenAIRE
- Journal :
- The Astronomical Journal
- Accession number :
- edsair.doi...........fd446c57af069426525fc1432c9c44ef