We present the first evidence for the binarity of four targets in the TESS field.The temperatures are estimated by SED analysis and the orbital periods are determined.The TESS light curves of the systems are analyzed ...We present the first evidence for the binarity of four targets in the TESS field.The temperatures are estimated by SED analysis and the orbital periods are determined.The TESS light curves of the systems are analyzed and the orbital and the absolute parameters are derived.The targets are also compared to wellstudied binary systems with the same morphological type and their evolutionary states are discussed.Our results indicate that the stars belong to the class of eclipsing detached binary systems.展开更多
The first BV bands photometric observations and the low-resolution spectrum of the shortest period Am type eclipsing binary TYC 6408-989-1 have been obtained.The stellar atmospheric parameters of the primary star were...The first BV bands photometric observations and the low-resolution spectrum of the shortest period Am type eclipsing binary TYC 6408-989-1 have been obtained.The stellar atmospheric parameters of the primary star were obtained through the spectral fitting as follows:Teff=6990±117 K,log g=4.25±0.26 cm s^(-2),[Fe/H]=-0.45±0.03 dex.The original spectra obtained by European Southern Observatory(ESO)were processed with an IRAF package by us.Based on the ESO blue-violet spectra,TYC 6408-989-1 was concluded as a marginal Am(Am:)star with a spectral type of kA3 hF1 mA5Ⅳ-Ⅴidentified through the MKCLASS program.The observed light curves were analyzed through the WilsonDevinney code.The final photometric solutions show that TYC 6408-989-1 is a marginal contact binary with a low mass ratio(q=0.27).The temperature of the secondary component derived through the light curve analysis is significantly higher than main sequence stars.In addition,TYC 6408-989-1 is a poor thermal contact binary.The temperature differences between the two components is about 1800 K.TYC6408-989-1 should be located in the oscillation stage predicted by the thermal relaxation oscillations theory(TRO)and will evolve into the shallow contact stage eventually.The very short period(less than one day),marginal Am peculiarity and quite large rotational velocity(v sin i■160 km s^(-1))make TYC 6408-989-1 become a challenge to the cut-off of rotation velocities and periods of Am stars.We have collected the well known eclipsing Am binaries with absolute parameters from the literature.展开更多
大型风电基地风电消纳的可行方案是跨区域直接送至负荷中心进行消化,由此产生大规模风电远距离输电的问题,进而对区域间最大输电能力(Total Transfer Capability,TTC)的计算提出新需求。针对大规模风电经直流外送的区域输电能力计算,结...大型风电基地风电消纳的可行方案是跨区域直接送至负荷中心进行消化,由此产生大规模风电远距离输电的问题,进而对区域间最大输电能力(Total Transfer Capability,TTC)的计算提出新需求。针对大规模风电经直流外送的区域输电能力计算,结合风火打捆直流外送方式,建立了风电经直流外送的区域间TTC计算模型,并采用交直流交替迭代连续潮流算法进行求解。采用改进的IEEE 39节点系统进行测试,对大规模风电经交、直流2种外送方式下的TTC进行对比计算,并讨论了不同风电场出力情况及风火打捆比例对TTC的影响。结果表明:在既定网架结构下,需要协调考虑风火打捆比例和线路容量,在尽可能多地接纳风电的同时,使系统获得最大输电能力。展开更多
基金the TESS mission is provided by NASA’s Science Mission DirectorateSupport for MAST for non-HST data is provided by the NASA Office of Space Science via grant NNX13AC07G and by other grants and contracts+1 种基金This publication makes use of VOSA,developed under the Spanish Virtual Observatory project supported by the Spanish MINECO through grant AyA2017–84089VOSA has been partially updated by using funding from the European Union’s Horizon 2020 Research and Innovation Programme,under Grant Agreement No.776403(EXOPLANETS-A)。
文摘We present the first evidence for the binarity of four targets in the TESS field.The temperatures are estimated by SED analysis and the orbital periods are determined.The TESS light curves of the systems are analyzed and the orbital and the absolute parameters are derived.The targets are also compared to wellstudied binary systems with the same morphological type and their evolutionary states are discussed.Our results indicate that the stars belong to the class of eclipsing detached binary systems.
基金partly supported by the National Natural Science Foundation of China(Nos.11922306 and U1831109)the Natural Science Foundation of Shandong Province(Nos.ZR2020QA048)+1 种基金the CAS Interdisciplinary Innovation Teampartially supported by the Open Project Program of the Key Laboratory of Optical Astronomy,National Astronomical Observatories,Chinese Academy of Sciences。
文摘The first BV bands photometric observations and the low-resolution spectrum of the shortest period Am type eclipsing binary TYC 6408-989-1 have been obtained.The stellar atmospheric parameters of the primary star were obtained through the spectral fitting as follows:Teff=6990±117 K,log g=4.25±0.26 cm s^(-2),[Fe/H]=-0.45±0.03 dex.The original spectra obtained by European Southern Observatory(ESO)were processed with an IRAF package by us.Based on the ESO blue-violet spectra,TYC 6408-989-1 was concluded as a marginal Am(Am:)star with a spectral type of kA3 hF1 mA5Ⅳ-Ⅴidentified through the MKCLASS program.The observed light curves were analyzed through the WilsonDevinney code.The final photometric solutions show that TYC 6408-989-1 is a marginal contact binary with a low mass ratio(q=0.27).The temperature of the secondary component derived through the light curve analysis is significantly higher than main sequence stars.In addition,TYC 6408-989-1 is a poor thermal contact binary.The temperature differences between the two components is about 1800 K.TYC6408-989-1 should be located in the oscillation stage predicted by the thermal relaxation oscillations theory(TRO)and will evolve into the shallow contact stage eventually.The very short period(less than one day),marginal Am peculiarity and quite large rotational velocity(v sin i■160 km s^(-1))make TYC 6408-989-1 become a challenge to the cut-off of rotation velocities and periods of Am stars.We have collected the well known eclipsing Am binaries with absolute parameters from the literature.
文摘大型风电基地风电消纳的可行方案是跨区域直接送至负荷中心进行消化,由此产生大规模风电远距离输电的问题,进而对区域间最大输电能力(Total Transfer Capability,TTC)的计算提出新需求。针对大规模风电经直流外送的区域输电能力计算,结合风火打捆直流外送方式,建立了风电经直流外送的区域间TTC计算模型,并采用交直流交替迭代连续潮流算法进行求解。采用改进的IEEE 39节点系统进行测试,对大规模风电经交、直流2种外送方式下的TTC进行对比计算,并讨论了不同风电场出力情况及风火打捆比例对TTC的影响。结果表明:在既定网架结构下,需要协调考虑风火打捆比例和线路容量,在尽可能多地接纳风电的同时,使系统获得最大输电能力。
