The orbital kinematics of η Carinae over three periastra with a possible detection of the elusive secondary's motion
Abstract
The binary η Carinae is the closest example of a very massive star, which may have formed through a merger during its Great Eruption in the mid-19th century. We aimed to confirm and improve the kinematics using a spectroscopic data set taken with the Cerro Tololo Inter-American Observatory 1.5-m telescope over the time period of 2008–2020, covering three periastron passages of the highly eccentric orbit. We measure line variability of H α and H β, where the radial velocity and orbital kinematics of the primary star were measured from the H β emission line using a bisector method. At phases away from periastron, we observed the He ii 4686 emission moving opposite the primary star, consistent with a possible Wolf–Rayet companion, although with a seemingly narrow emission line. This could represent the first detection of emission from the companion.
Additional Information
© 2023 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model). We thank our referee, Tomer Shenar, for many suggestions that improved this paper. These results are the outcome of many allocations of telescope time for the CTIO 1.5-m telescope and echelle spectrographs. We thank internal SMARTS allocations at Georgia State University, as well as NOIR Lab (formerly NOAO) allocations of NOAO-09B-153, NOAO-12A-216, NOAO-12B-194, NOAO-13B-328, NOAO-15A-0109, NOAO-18A-0295, NOAO-19B-204, NOIRLab-20A-0054, and NOIRLab-21B-0334. This research has used data from the CTIO/SMARTS 1.5-m telescope, which is operated as part of the SMARTS Consortium by RECONS (www.recons.org) members Todd Henry, Hodari James, Wei-Chun Jao, and Leonardo Paredes. At the telescope, observations were carried out by Roberto Aviles and Rodrigo Hinojosa. CSP and AL were partially supported by the Embry-Riddle Aeronautical University Undergraduate Research Institute. ES acknowledges support from the Arizona Space Grant programme. NDR, CSP, AL, ES, and TRG acknowledge support from the HST GO Programs #15611 and #15992. AD thanks FAPESP (2011/51680-6 and 2019/02029-2) for support. AFJM is grateful for financial aid from NSERC (Canada). The material is based upon work supported by NASA under award number 80GSFC21M0002. The work of ANC was supported by NOIRLab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. DATA AVAILABILITY. All measurements can be found in Appendix A. Reasonable requests to use the reduced spectra will be granted by the corresponding author.Attached Files
Published - stad018.pdf
Supplemental Material - stad018_supplemental_files.zip
Files
| Name | Size | Download all |
|---|---|---|
|
md5:adffc905a60cb4719fb06ba0331a3492
|
16.1 kB | Preview Download |
|
md5:ae8499efc188fb53d8457128209689c2
|
1.5 MB | Preview Download |
Additional details
- Eprint ID
- 120036
- Resolver ID
- CaltechAUTHORS:20230314-845495900.63
- Embry-Riddle Aeronautical University
- Arizona Space Grant
- HST GO-15611
- NASA
- HST GO-15992
- NASA
- 2011/51680-6
- Fundação de Amparo à Pesquisa do Estado de Sao Paulo (FAPESP)
- 2019/02029-2
- Fundação de Amparo à Pesquisa do Estado de Sao Paulo (FAPESP)
- Natural Sciences and Engineering Research Council of Canada (NSERC)
- 80GSFC21M0002
- NASA
- NOIRLab
- Created
-
2023-05-17Created from EPrint's datestamp field
- Updated
-
2023-05-17Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)