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Eggen, Øyvind; Sending, Ole Jacob

doi:10.18261/issn1891-1757-2012-02-04

Cited by 12 publications

(15 citation statements)

References 5 publications

(6 reference statements)

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“…This program lasted for almost 10 yr, and a series of papers was published (e.g., Lu & Rucinski 1999;Rucinski 2002;) that has greatly increased the samples of late-type CBs with RV data. Among those CBs, the K-type systems have the shortest periods, which are close to the period cutoff (∼0.22 day) according to the period-color relation (Eggen 1967;Rucinski 2002). From their RV data, it is inferred that almost all of the K-type CBs are W-subtype systems (see Section 4).…”

Section: Introductionmentioning

confidence: 94%

Comparative Study of TESS Photometry and Radial Velocities on Six Early K-type Contact Binaries with Similar Periods around 0.268 Day

Liu

Qian

Liao

et al. 2023

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High-precision light curves were extracted from TESScut images. Together with APOGEE and LAMOST medium-resolution spectra, a joint study was made for six early K-type contact binary candidates selected unbiasedly with orbital periods around 0.268 day. It is found that all of them (RV CVn, EK Com, V384 Ser, V1038 Her, EH CVn, and CSS_J125403.7+503945) are W-subtype shallow contact systems, though with different mass ratios (1/q = 0.27–0.62). The effective temperature differences between the binary components are around a few hundred kelvins. The original definitions of the A and W subtypes were compared with the customarily used methods, which rely on the shape or photometric solutions of the light curves. The latter two methods are not always reliable; therefore, the radial velocity analysis is strongly recommended. Through a collection of all available K-type contact binaries with both photometric and spectroscopic measurements, it is found that almost all of them are W-subtype systems, except for a few objects that have nearly identical temperatures for binary components. This W-subtype phenomenon for K-type contact binaries should be further checked with more samples in the future. Finally, the physical parameters of the targets were determined with joint data analysis, and the multiplicity is discussed for these targets. Objects V384 Ser and RV CVn are confirmed to very likely be triple systems from comprehensive analysis, while V1038 Her is a candidate of a triple system based on photometric and spectroscopic solutions.

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Section: Introductionmentioning

confidence: 94%

Comparative Study of TESS Photometry and Radial Velocities on Six Early K-type Contact Binaries with Similar Periods around 0.268 Day

Liu

Qian

Liao

et al. 2023

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“…There is a clear correlation between the orbital period and the temperature of the primary star. The period-temperature relationship is actually the well-known PLC relations (Eggen 1967;Rucinski 1994;Chen et al 2016Chen et al , 2018bMateo & Rucinski 2017;Qian et al 2017;Jayasinghe et al 2020a;Qian et al 2020). Most CBs are located in a banded region rather than a simple linear PLC.…”

Section: Plc Relationsmentioning

confidence: 99%

“…Therefore, to understand the formation and evolution of CBs, EW-type eclipsing binaries are generally studied. The well-known period-luminosity-color (PLC) relations (Eggen 1967;Rucinski 1994;Chen et al 2016;Mateo & Rucinski 2017;Qian et al 2017;Chen et al 2018b;Jayasinghe et al 2020a;Qian et al 2020) of CBs are established by using different passband photometric data of EW-type eclipsing binaries. The PLC relations are different between early-and late-type CBs (Jayasinghe et al 2020a), and the PLC relations of different types of CBs have been extensively studied (Rucinski 1994;Graczyk et al 2011;Chen et al 2016Chen et al , 2018bPawlak et al 2016;Mateo & Rucinski 2017;Qian et al 2017;Chen et al 2018a;Jayasinghe et al 2020a;Qian et al 2020).…”

Section: Introductionmentioning

confidence: 99%

Physical Parameters of 11,100 Short-period ASAS-SN Eclipsing Contact Binaries

Li 李,

Zhu 朱,

Ding 丁

et al. 2024

ApJS

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Starting from more than 11,200 short-period (less than 0.5 days) EW-type eclipsing binary candidates with the All-Sky Automated Survey for Supernovae V-band light curves, we use the Markov Chain Monte Carlo algorithm and neural networks to obtain the mass ratio (q), orbital inclination (incl), fill-out factor (f), and temperature ratio (T s /T p ). After crossmatching with the Gaia DR3 database, the final sample contains parameters of 2399 A-type and 8712 W-type contact binaries (CBs). We present the distributions of parameters of these 11,111 short-period CBs. The mass ratio (q) and fill-out factor (f) are found to obey log-normal distributions, and the remaining parameters obey normal distributions. There is a significant period–temperature correlation of these CBs. Additionally, the temperature ratio (T s /T p ) tends to increase as the orbital period decreases for W-type CBs. There is no significant correlation between them for A-type CBs. The mass ratio and fill-out factor (q−f) diagram suggest there is no significant correlation between these two parameters. A clear correlation exists between the mass ratio and radius ratio. The radius ratio increases with the mass ratio. Moreover, the deep fill-out CBs tend to fall on the upper boundary of the q−R s /R p distribution, while the shallow fill-out CBs fall on the lower boundary.

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“…Since CBs proposed as distance tracers by Eggen (1967), various studies have tried to establish PL and periodluminosity-color (PLC) relations of CBs. This issue has also attracted attention and research of Ruciński (1974).…”

Section: Introductionmentioning

confidence: 99%

Period–Luminosity–Metallicity–Color Relations of Late-type Contact Binaries in the Big Data Era

Song,

Tian

2024

ApJ

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Binary stars ubiquitous throughout the Universe are important. Contact binaries (CBs) possessing period–luminosity (PL) relations could be adopted as distance tracers. The PL relations of CBs are influenced by metallicity abundance and color index, which are connected to both the radius and luminosity of stars. Here we propose fine relations of the period–luminosity–metallicity–color (PLZC) from the ultraviolet to infrared bands based on current surveys. The accuracy of the distance estimation is 6% and 8%, respectively, depending on the PLZC relations of the CBs in the infrared and optical bands of the collected data. PLZC models are still more accurate than PLC models in determining intrinsic luminosity, notwithstanding their limited improvement. Meanwhile, these relations based on synthetic photometry are also calibrated. On the basis of the synthetic photometry, a 6% accuracy of distance is estimated. The measured or synthetic data of PLZC or PLC relations in infrared bands comes first in the list of suggestions for distance estimations and is followed by the measured data of optical bands.

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Abstract: Tidligere norske misjonaerer inkluderte Hans Egede på Grønland og H. C. Knudsen som reiste til Afrika, men for et tysk misjonsselskap.

Cited by 12 publications

References 5 publications

Comparative Study of TESS Photometry and Radial Velocities on Six Early K-type Contact Binaries with Similar Periods around 0.268 Day

Comparative Study of TESS Photometry and Radial Velocities on Six Early K-type Contact Binaries with Similar Periods around 0.268 Day

Physical Parameters of 11,100 Short-period ASAS-SN Eclipsing Contact Binaries

Period–Luminosity–Metallicity–Color Relations of Late-type Contact Binaries in the Big Data Era

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