Table · dataset · 2023
Blue Straggler Stars in the Open Cluster NGC 6819
Listed in IVOA Registry (Virtual Observatory)
NGC6819 is an open cluster of age 2.4Gyr that was in the NASA Kepler spacecraft's field of view from 2009 to 2013.
Description
The central part of the cluster was observed in a 200x200pixel "superstamp" during these four years in 30minute cadence photometry, providing a unique, high-precision, long time-series data set. The cluster contains "blue straggler" stars, i.e., stars on the main sequence above the cluster turnoff that should have left the main sequence to become red giants.
We present light curves and pulsation frequency analyses derived from custom photometric reductions for five confirmed cluster members-four blue stragglers and one star near the main-sequence turnoff. Two of these stars show a rich spectrum of {delta}Scuti pulsation modes, with 236 and 124 significant frequencies identified, respectively, while two stars show mainly low-frequency modes, characteristic of {gamma}Doradus variable stars.
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The fifth star, a known active X-ray binary, shows only several harmonics of two main frequencies. For the two {delta}Scuti stars, we use a frequency separation-mean density relation to estimate their mean densities, and then use these values along with their effective temperature to derive their stellar masses and radii. For the two stars showing low frequencies, we searched for period-spacing sequences that may be representative of gravity-mode or Rossby-mode sequences, but found no clear sequences.
The common age for the cluster members, considered along with the frequencies, will provide valuable constraints for asteroseismic analyses, and may shed light on the origin of the blue stragglers.
Links
Where it is published
- Reference page cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/165/188 ↗
landing page · from IVOA Registry
Documentation and papers
- ADS 2023AJ....165..188G ui.adsabs.harvard.edu/abs/2023AJ....165..188G ↗
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/aj/165/188 ↗
catalogue entry · from IVOA Registry
Topics
- Stated by source
- Optical
- From keywords
- Astronomy & Astrophysics
- Inferred from text
- Astronomical sciences 71%
Provenance · 1 source records, 9 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| IVOA Registry (Virtual Observatory) | ivo://cds.vizier/j/aj/165/188 | 11 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 (71%) |
| 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 |