Absolute properties of the low-mass eclipsing binary CM Draconis
| Autor: | Guillem Anglada-Escudé, D. H. Bradstreet, Mark E. Everett, Juan Carlos Morales, Ignasi Ribas, Francis T. O'Donovan, Guillermo Torres, David W. Latham, Georgi Mandushev, David Charbonneau, Carme Jordi, José A. Gallardo, Marek Wolf, Edward F. Guinan, Robert D. Mathieu |
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| Rok vydání: | 2008 |
| Předmět: |
Binaries: eclipsing
Binary number FOS: Physical sciences Astrophysics Binaries: spectroscopic Stars: late-type individual (CM Dra) [Stars] 01 natural sciences fundamental parameters [Stars] spectroscopic [Binaries] 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Stellar structure 010303 astronomy & astrophysics Stars: fundamental parameters Eclipse Physics 010308 nuclear & particles physics Apsidal precession eclipsing [Binaries] Astrophysics (astro-ph) Astronomy and Astrophysics Light curve Stars: individual (CM Dra) Radial velocity Stars Space and Planetary Science late-type [Stars] Astrophysics::Earth and Planetary Astrophysics Low Mass |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| DOI: | 10.48550/arxiv.0810.1541 |
| Popis: | 12 pages, 7 figures.-- ArXiv pre-print available at: http://arxiv.org/abs/0810.1541 Spectroscopic and eclipsing binary systems offer the best means for determining accurate physical properties of stars, including their masses and radii. The data available for low-mass stars have yielded firm evidence that stellar structure models predict smaller radii and higher effective temperatures than observed, but the number of systems with detailed analyses is still small. In this paper, we present a complete reanalysis of one of such eclipsing systems, CM Dra, composed of two dM4.5 stars. New and existing light curves as well as a radial velocity curve are modeled to measure the physical properties of both components. The masses and radii determined for the components of CM Dra are M1 = 0.2310 ± 0.0009 Msun, M2 = 0.2141 ± 0.0010 Msun, R1 = 0.2534 ± 0.0019 Rsun, and R2 = 0.2396 ± 0.0015 Rsun. With relative uncertainties well below the 1% level, these values constitute the most accurate properties to date for fully convective stars. This makes CM Dra a valuable benchmark for testing theoretical models. In comparing our measurements with theory, we confirm the discrepancies previously reported for other low-mass eclipsing binaries. These discrepancies seem likely to be due to the effects of magnetic activity. We find that the orbit of this system is slightly eccentric, and we have made use of eclipse timings spanning three decades to infer the apsidal motion and other related properties. JCM, IR and CJ acknowledge support from the Spanish Ministerio de Educación y Ciencia via grants AYA2006-15623-C02-01 and AYA2006-15623-C02-02. GT acknowledges partial support for this work from NSF grant AST-0708229 and NASA’s MASSIF SIM Key Project (BLF57-04). EFG acknowledges support for the FCAPT research under NSF/RUI grant AST05-07536. DC and FTOD acknowledge support for the Sleuth Observatory work by the National Aeronautics and Space Administration under grant NNG05GJ29G issued through the Origins of Solar Systems Program. FTOD also acknowledges partial support for this work provided through the NASA Postdoctoral Program at the Goddard Space Flight Center, administered by Oak Ridge Associated Universities through a contract with NASA. The investigation of MW was supported by the Grant Agency of the Czech Republic under grant No. 205/06/0217. |
| Databáze: | OpenAIRE |
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