{"title":"V694 Peg 中 W 型现象的可能解释","authors":"Hu-Shan Xu, Li-Ying Zhu","doi":"arxiv-2409.09705","DOIUrl":null,"url":null,"abstract":"Three sets of complete multi-color light curves of V694 Peg observed in 2013,\n2015 and 2019 were presented and analyzed. Our photometric solutions show that\nthis system is an A-type shallow contact binary in 2013 and 2015, while it\nconverted to a W-type one in 2019. A large cool spot on the component of this\nbinary could explain the conversion, implying the W-type phenomena may be\ncaused by magnetic activity of the components. We have collected available data\nof this binary and calculated 505 times of light minimum, which span 17 years.\nThe orbital period investigation based on these timings shows there is a\nlong-term period increase at a rate of $dP/dt$ = 4.3($\\pm$ 0.3)$\\times$\n10$^{-9}$ d yr$^{-1}$ superposed on a periodic variation with a period of\n11.81($\\pm$ 0.06) years. The cyclic orbital variation may be the result of\nmagnetic activity cycles or the existence of a third body. Till now, only 8\ntransformed systems including V694 Peg have been reported. Compared with other\nconverting contact systems between A-type and W-type, V694 Peg is recorded as\nthe shortest-period one. All of these converting systems are late-type (later\nthan F7) contact binaries with O'Connell effect and show cyclic period\nvariation, which indicates that magnetic activity may be the reason for the\nconversion between the two types of contact binaries. For investigating the\nnature of A-type and W-type phenomena, the discovery of more converting contact\nbinaries is essential.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"A possible explanation of W-type phenomena in V694 Peg\",\"authors\":\"Hu-Shan Xu, Li-Ying Zhu\",\"doi\":\"arxiv-2409.09705\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Three sets of complete multi-color light curves of V694 Peg observed in 2013,\\n2015 and 2019 were presented and analyzed. Our photometric solutions show that\\nthis system is an A-type shallow contact binary in 2013 and 2015, while it\\nconverted to a W-type one in 2019. A large cool spot on the component of this\\nbinary could explain the conversion, implying the W-type phenomena may be\\ncaused by magnetic activity of the components. We have collected available data\\nof this binary and calculated 505 times of light minimum, which span 17 years.\\nThe orbital period investigation based on these timings shows there is a\\nlong-term period increase at a rate of $dP/dt$ = 4.3($\\\\pm$ 0.3)$\\\\times$\\n10$^{-9}$ d yr$^{-1}$ superposed on a periodic variation with a period of\\n11.81($\\\\pm$ 0.06) years. The cyclic orbital variation may be the result of\\nmagnetic activity cycles or the existence of a third body. Till now, only 8\\ntransformed systems including V694 Peg have been reported. Compared with other\\nconverting contact systems between A-type and W-type, V694 Peg is recorded as\\nthe shortest-period one. All of these converting systems are late-type (later\\nthan F7) contact binaries with O'Connell effect and show cyclic period\\nvariation, which indicates that magnetic activity may be the reason for the\\nconversion between the two types of contact binaries. For investigating the\\nnature of A-type and W-type phenomena, the discovery of more converting contact\\nbinaries is essential.\",\"PeriodicalId\":501068,\"journal\":{\"name\":\"arXiv - PHYS - Solar and Stellar Astrophysics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-09-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - PHYS - Solar and Stellar Astrophysics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2409.09705\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - PHYS - Solar and Stellar Astrophysics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2409.09705","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
A possible explanation of W-type phenomena in V694 Peg
Three sets of complete multi-color light curves of V694 Peg observed in 2013,
2015 and 2019 were presented and analyzed. Our photometric solutions show that
this system is an A-type shallow contact binary in 2013 and 2015, while it
converted to a W-type one in 2019. A large cool spot on the component of this
binary could explain the conversion, implying the W-type phenomena may be
caused by magnetic activity of the components. We have collected available data
of this binary and calculated 505 times of light minimum, which span 17 years.
The orbital period investigation based on these timings shows there is a
long-term period increase at a rate of $dP/dt$ = 4.3($\pm$ 0.3)$\times$
10$^{-9}$ d yr$^{-1}$ superposed on a periodic variation with a period of
11.81($\pm$ 0.06) years. The cyclic orbital variation may be the result of
magnetic activity cycles or the existence of a third body. Till now, only 8
transformed systems including V694 Peg have been reported. Compared with other
converting contact systems between A-type and W-type, V694 Peg is recorded as
the shortest-period one. All of these converting systems are late-type (later
than F7) contact binaries with O'Connell effect and show cyclic period
variation, which indicates that magnetic activity may be the reason for the
conversion between the two types of contact binaries. For investigating the
nature of A-type and W-type phenomena, the discovery of more converting contact
binaries is essential.