FORCASTing the Spectroscopic Dust Properties of the WC+O Binary WR 137 with SOFIA
WR 137 (HD 192641) is a binary system consisting of a carbon-rich Wolf–Rayet (W-R) star and an Oe companion star in a 13 yr orbit. Near periastron, the winds of the two stars collide and form carbonaceous dust. We obtained three mid-infrared grism spectra of the system with SOFIA and FORCAST during...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/acf201 |
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| author | Megan J. Peatt Noel D. Richardson Peredur M. Williams Nicole Karnath Victor I. Shenavrin Ryan M. Lau Anthony F. J. Moffat Gerd Weigelt |
| author_facet | Megan J. Peatt Noel D. Richardson Peredur M. Williams Nicole Karnath Victor I. Shenavrin Ryan M. Lau Anthony F. J. Moffat Gerd Weigelt |
| author_sort | Megan J. Peatt |
| collection | DOAJ |
| description | WR 137 (HD 192641) is a binary system consisting of a carbon-rich Wolf–Rayet (W-R) star and an Oe companion star in a 13 yr orbit. Near periastron, the winds of the two stars collide and form carbonaceous dust. We obtained three mid-infrared grism spectra of the system with SOFIA and FORCAST during the last year of SOFIA’s operations in 2021 July, 2021 February, and 2022 May (Cycle 9). Within these spectra, we have identified several wind lines from He i , He ii , C iii , and C iv that are emitted from the W-R wind as well as a weak emission feature around 6.3–6.4 μ m that may have shifted its peak flux from 6.29 to 6.41 μ m through this time period. The weak feature grew as the continuum dust emission grew while the W-R emission appeared to decline due to lower contrast with the continuum. Furthermore, we observe that the peak of the feature shifts to redder wavelengths during the observations. We compare this feature to the unidentified infrared feature and other emission lines identified in dusty carbon-rich W-R (WC) binaries. For WR 137, we speculate that mixing of the winds in the system with the Oe star’s disk is important for starting the dust formation and that it is less important as dust formation continues. Previous infrared photometry shows “minieruptions” of dust production, which could then be explained with variations of the Oe star disk. |
| first_indexed | 2024-03-11T18:41:58Z |
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| id | doaj.art-a9eb931c1d164effb43c1ab385002cef |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-11T18:41:58Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-a9eb931c1d164effb43c1ab385002cef2023-10-12T12:53:15ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-01956210910.3847/1538-4357/acf201FORCASTing the Spectroscopic Dust Properties of the WC+O Binary WR 137 with SOFIAMegan J. Peatt0Noel D. Richardson1https://orcid.org/0000-0002-2806-9339Peredur M. Williams2https://orcid.org/0000-0002-8092-980XNicole Karnath3https://orcid.org/0000-0003-3682-854XVictor I. Shenavrin4https://orcid.org/0000-0002-2287-8151Ryan M. Lau5https://orcid.org/0000-0003-0778-0321Anthony F. J. Moffat6https://orcid.org/0000-0002-4333-9755Gerd Weigelt7https://orcid.org/0000-0001-9754-2233Department of Physics and Astronomy, Embry-Riddle Aeronautical University , 3700 Willow Creek Rd., Prescott, AZ 86301, USA ; noel.richardson@erau.eduDepartment of Physics and Astronomy, Embry-Riddle Aeronautical University , 3700 Willow Creek Rd., Prescott, AZ 86301, USA ; noel.richardson@erau.eduInstitute for Astronomy, University of Edinburgh , Royal Observatory, Edinburgh EH9 3HJ, UKSpace Science Institute , 4765 Walnut St., Suite B Boulder, CO 80301, USA; Center for Astrophysics Harvard & Smithsonian , Cambridge, MA 02138, USASternberg Astronomical Institute, Moscow State University , Universitetskij pr., 13, Moscow, 119991, RussiaNSF’s NOIRLab , 950 N. Cherry Avenue, Tucson, AZ 85719, USADépartement de physique, Université de Montréal , Complexe des Sciences, 1375 Avenue Thérèse-Lavoie-Roux, Montréal, Quebéc, H2V 0B3, CanadaMax Planck Institute for Radio Astronomy , Auf dem Hügel 69, D-53121 Bonn, GermanyWR 137 (HD 192641) is a binary system consisting of a carbon-rich Wolf–Rayet (W-R) star and an Oe companion star in a 13 yr orbit. Near periastron, the winds of the two stars collide and form carbonaceous dust. We obtained three mid-infrared grism spectra of the system with SOFIA and FORCAST during the last year of SOFIA’s operations in 2021 July, 2021 February, and 2022 May (Cycle 9). Within these spectra, we have identified several wind lines from He i , He ii , C iii , and C iv that are emitted from the W-R wind as well as a weak emission feature around 6.3–6.4 μ m that may have shifted its peak flux from 6.29 to 6.41 μ m through this time period. The weak feature grew as the continuum dust emission grew while the W-R emission appeared to decline due to lower contrast with the continuum. Furthermore, we observe that the peak of the feature shifts to redder wavelengths during the observations. We compare this feature to the unidentified infrared feature and other emission lines identified in dusty carbon-rich W-R (WC) binaries. For WR 137, we speculate that mixing of the winds in the system with the Oe star’s disk is important for starting the dust formation and that it is less important as dust formation continues. Previous infrared photometry shows “minieruptions” of dust production, which could then be explained with variations of the Oe star disk.https://doi.org/10.3847/1538-4357/acf201Wolf-Rayet starsEarly-type starsOe starsDust formationBinary starsStellar winds |
| spellingShingle | Megan J. Peatt Noel D. Richardson Peredur M. Williams Nicole Karnath Victor I. Shenavrin Ryan M. Lau Anthony F. J. Moffat Gerd Weigelt FORCASTing the Spectroscopic Dust Properties of the WC+O Binary WR 137 with SOFIA The Astrophysical Journal Wolf-Rayet stars Early-type stars Oe stars Dust formation Binary stars Stellar winds |
| title | FORCASTing the Spectroscopic Dust Properties of the WC+O Binary WR 137 with SOFIA |
| title_full | FORCASTing the Spectroscopic Dust Properties of the WC+O Binary WR 137 with SOFIA |
| title_fullStr | FORCASTing the Spectroscopic Dust Properties of the WC+O Binary WR 137 with SOFIA |
| title_full_unstemmed | FORCASTing the Spectroscopic Dust Properties of the WC+O Binary WR 137 with SOFIA |
| title_short | FORCASTing the Spectroscopic Dust Properties of the WC+O Binary WR 137 with SOFIA |
| title_sort | forcasting the spectroscopic dust properties of the wc o binary wr 137 with sofia |
| topic | Wolf-Rayet stars Early-type stars Oe stars Dust formation Binary stars Stellar winds |
| url | https://doi.org/10.3847/1538-4357/acf201 |
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