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http://hdl.handle.net/2445/207408
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DC Field | Value | Language |
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dc.contributor.author | Ratzloff, Jeffrey K. | - |
dc.contributor.author | Corbett, Henry T. | - |
dc.contributor.author | Law, Nicholas M. | - |
dc.contributor.author | Barlow, Brad N. | - |
dc.contributor.author | Glazier, Amy | - |
dc.contributor.author | Howard, Ward S. | - |
dc.contributor.author | Fors Aldrich, Octavi | - |
dc.contributor.author | Ser Badia, Daniel del | - |
dc.contributor.author | Trifonov, Trifon | - |
dc.date.accessioned | 2024-02-09T17:14:20Z | - |
dc.date.available | 2024-02-09T17:14:20Z | - |
dc.date.issued | 2019-08-01 | - |
dc.identifier.issn | 0004-6280 | - |
dc.identifier.uri | http://hdl.handle.net/2445/207408 | - |
dc.description.abstract | The regions around the celestial poles offer the ability to find and characterize long-term variables from ground-based observatories. We used multi-year Evryscope data to search for high-amplitude (≈5% or greater) variable objects among 160,000 bright stars (mv < 14.5) near the South Celestial Pole. We developed a machine-learning-based spectral classifier to identify eclipse and transit candidates with M-dwarf or K-dwarf host stars, and potential low-mass secondary stars or gas-giant planets. The large amplitude transit signals from low-mass companions of smaller dwarf host stars lessens the photometric precision and systematics removal requirements necessary for detection, and increases the discoveries from long-term observations with modest light-curve precision among the faintest stars in the survey. The Evryscope is a robotic telescope array that observes the Southern sky continuously at 2-minute cadence, searching for stellar variability, transients, transits around exotic stars and other observationally challenging astrophysical variables. The multi-year photometric stability is better than 1% for bright stars in uncrowded regions, with a 3<em>σ</em> limiting magnitude of g = 16 in dark time. In this study, covering all stars 9 < mv < 14.5, in declinations −75° to −90°, and searching for high-amplitude variability, we recover 346 known variables and discover 303 new variables, including 168 eclipsing binaries. We characterize the discoveries and provide the amplitudes, periods, and variability type. A 1.7 RJ planet candidate with a late K-dwarf primary was found and the transit signal was verified with the PROMPT telescope network. Further follow-up revealed this object to be a likely grazing eclipsing binary system with nearly identical primary and secondary K5 stars. Radial-velocity measurements from the Goodman Spectrograph on the 4.1 meter SOAR telescope of the likely lowest-mass targets reveal that six of the eclipsing binary discoveries are low-mass (.06–.37 <em>M</em>⊙) secondaries with K-dwarf primaries, strong candidates for precision mass–radius measurements. | - |
dc.format.extent | 35 p. | - |
dc.format.mimetype | application/pdf | - |
dc.language.iso | eng | - |
dc.publisher | Astronomical Society of the Pacific | - |
dc.relation.isformatof | Reproducció del document publicat a: https://doi.org/10.1088/1538-3873/ab1d77 | - |
dc.relation.ispartof | Publications of the Astronomical Society of the Pacific, 2019, vol. 131, num.1002, p. 1-35 | - |
dc.relation.uri | https://doi.org/10.1088/1538-3873/ab1d77 | - |
dc.rights | (c) Ratzloff, Jeffrey K. et al., 2019 | - |
dc.source | Articles publicats en revistes (Física Quàntica i Astrofísica) | - |
dc.subject.classification | Planetes | - |
dc.subject.classification | Satèl·lits | - |
dc.subject.classification | Regions polars | - |
dc.subject.other | Planets | - |
dc.subject.other | Satellites | - |
dc.subject.other | Polar regions | - |
dc.title | Variables in the Southern Polar Region Evryscope 2016 Data Set | - |
dc.type | info:eu-repo/semantics/article | - |
dc.type | info:eu-repo/semantics/publishedVersion | - |
dc.identifier.idgrec | 694732 | - |
dc.date.updated | 2024-02-09T17:14:20Z | - |
dc.rights.accessRights | info:eu-repo/semantics/openAccess | - |
Appears in Collections: | Articles publicats en revistes (Física Quàntica i Astrofísica) Articles publicats en revistes (Institut de Ciències del Cosmos (ICCUB)) |
Files in This Item:
File | Description | Size | Format | |
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222761.pdf | 6.11 MB | Adobe PDF | View/Open |
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