Table · dataset · 2019
20yr obs. of the spectroscopic binary EC 20117-4014
Listed in IVOA Registry (Virtual Observatory)
Among the competing evolution theories for subdwarf-B (sdB) stars is the binary evolution scenario.
Description
EC 20117-4014 (=V4640 Sgr) is a spectroscopic binary system consisting of a pulsating sdB star and a late F main-sequence companion; however, the period and the orbit semimajor axes have not been precisely determined. This paper presents orbital characteristics of the EC 20117-4014 binary system using 20 years of photometric data.
Periodic observed minus calculated (O-C) variations were detected in the two highest-amplitude pulsations identified in the EC 20117-4014 power spectrum, indicating the binary system's precise orbital period (P=792.3d) and the light-travel-time amplitude (A=468.9s). This binary shows no significant orbital eccentricity, and the upper limit of the eccentricity is 0.025 (using 3{sigma} as an upper limit). This upper limit of the eccentricity is the lowest among all wide sdB binaries with known orbital parameters.
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This analysis indicated that the sdB is likely to have lost its hydrogen envelope through stable Roche lobe overflow, thus supporting hypotheses for the origin of sdB stars. In addition to those results, the underlying pulsation period change obtained from the photometric data was dP/dt=5.4(+/-0.7)x10^-14^d.d^-1^, which shows that the sdB is just before the end of the core helium-burning phase.
Links
Where it is published
- Reference page cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/859/145 ↗
landing page · from IVOA Registry
Documentation and papers
- ADS 2018ApJ...859..145O ui.adsabs.harvard.edu/abs/2018ApJ...859..145O ↗
publication · from IVOA Registry
Catalogue records · 2
- VOResource record dc.g-vo.org/oai.xml?verb=GetRecord&metadataPrefix=ivo_vor&identifier=ivo%3… ↗
metadata API · from IVOA Registry
- Registry record (GAVO) dc.g-vo.org/I/cds.vizier/j/apj/859/145 ↗
catalogue entry · from IVOA Registry
Topics
- Stated by source
- Optical
- From keywords
- Astronomy & Astrophysics
- Inferred from text
- Astronomical sciences 70%
Provenance · 1 source records, 9 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| IVOA Registry (Virtual Observatory) | ivo://cds.vizier/j/apj/859/145 | 14 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| access_level | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[field].anzsrc:group:5101 | enrichment · IVOA Registry | taxonomy-embedding@1.1.0 | title+keywords+description (70%) |
| concepts[field].local:field:astronomy | mapping · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[modality].ivoa_waveband:optical | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| description | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_description |
| license_text | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| publication_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| title | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_title |
| updated_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 |