Bulletin de la Societe Royale des Sciences de Liege最新文献

A transit survey to search for planets around hot subdwarfs 在热亚矮星周围寻找行星的凌日巡天

Bulletin de la Societe Royale des Sciences de Liege Pub Date : 2023-01-01 DOI: 10.25518/0037-9565.11286

Antoine THUILLIER, Valérie VAN GROOTEL, Francisco J. POZUELOS, Martín DÉVORA-PAJARES, Stéphane CHARPINET, Lionel SIESS

引用次数: 2

New Hot Subdwarf Variables from Gaia eDR3 来自盖亚eDR3的新热亚矮星变量

Bulletin de la Societe Royale des Sciences de Liege Pub Date : 2023-01-01 DOI: 10.25518/0037-9565.11220

Isaac D. LOPEZ, Alekzander KOSAKOWSKI, Brad N. BARLOW, Thomas KUPFER

引用次数: 0

The cradle of nonlinear asteroseismology: observations of oscillation mode variability in compact pulsating stars 非线性星震学的摇篮:紧致脉动恒星振荡模态变率的观测

Bulletin de la Societe Royale des Sciences de Liege Pub Date : 2023-01-01 DOI: 10.25518/0037-9565.11305

Weikai ZONG, Stéphane CHARPINET, Gérard VAUCLAIR, Jian-Ning FU, Xiao-Yu MA

{"title":"The cradle of nonlinear asteroseismology: observations of oscillation mode variability in compact pulsating stars","authors":"Weikai ZONG, Stéphane CHARPINET, Gérard VAUCLAIR, Jian-Ning FU, Xiao-Yu MA","doi":"10.25518/0037-9565.11305","DOIUrl":"https://doi.org/10.25518/0037-9565.11305","url":null,"abstract":"We briefly review progress in developing a pathway to nonlinear astereoseismology, both from theoretical and observational aspects. As predicted by the theory of weak nonlinear interactions between resonant modes, their amplitude and frequency can be modulated according to vari-ous kinds of patterns. However, those subtle modulations could hardly be well characterized from ground-based photometric monitoring. The Kepler spacecraft offered a new window to find clear-cut evidence of well-determined amplitude and frequency modulations, leading to the first discoveries of such variations in pulsating white dwarf and hot B subdwarf stars. Fol-lowing that direction, a systematic survey of oscillation mode properties in compact pulsators monitored by Kepler suggests that mode variability is likely a common phenomenon, which remain unaccounted for by standard linear non-radial pulsation theory. To reach this conclusion firmly, the survey has now been extended to a larger context including compact stars observed by K2 and TESS. We expect that this extended survey will help to constrain key parameters governing weak nonlinear effects in stellar oscillations.","PeriodicalId":35838,"journal":{"name":"Bulletin de la Societe Royale des Sciences de Liege","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135052649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The fastest hot subdwarfs revisited 重新考察了速度最快的热亚矮星

Bulletin de la Societe Royale des Sciences de Liege Pub Date : 2023-01-01 DOI: 10.25518/0037-9565.11205

Ulrich HEBER, collaboration MUCHFUSS

引用次数: 0

Minéralogie et métallogenèse des filons de barite plombifère de Wisembach (Fauvillers), Province de Luxembourg, Belgique 比利时卢森堡省Wisembach (Fauvillers)管道重晶石矿脉的矿物学和成矿学

Bulletin de la Societe Royale des Sciences de Liege Pub Date : 2023-01-01 DOI: 10.25518/0037-9565.11131

Michel Blondieau, Frédéric Hatert, Stéphane Puccio, Martin Depret, Fabrice Dal Bo

引用次数: 0

The holoparasitic Orobanchaceae of Tlemcen region (north-western Algeria): diversity, distribution and host range 阿尔及利亚西北部特莱姆森地区的全寄生蛛科:多样性、分布和寄主范围

Bulletin de la Societe Royale des Sciences de Liege Pub Date : 2023-01-01 DOI: 10.25518/0037-9565.11342

Mansour Aissaoui, Brahim Babali, Amel Sari Ali

引用次数: 0

Eclipse Timing Variations Observed in PCEB Systems 在PCEB系统中观测到的日食时间变化

Bulletin de la Societe Royale des Sciences de Liege Pub Date : 2023-01-01 DOI: 10.25518/0037-9565.11197

Özgür Baştürk, Ekrem M. ESMER, Eylül DEMIR, Selim O. SELAM

{"title":"Eclipse Timing Variations Observed in PCEB Systems","authors":"Özgür Baştürk, Ekrem M. ESMER, Eylül DEMIR, Selim O. SELAM","doi":"10.25518/0037-9565.11197","DOIUrl":"https://doi.org/10.25518/0037-9565.11197","url":null,"abstract":"Post-common Envelope Eclipsing Binary (PCEB) systems with a white or sub-dwarf primary and a low-mass secondary are ideal systems to study Eclipse Timing Variations (ETVs) due to their relatively small total masses which make it easy to detect gravitationally bound, yet unseen, additional bodies even within planetary limits on long-period orbits. With the addition of the recent discovery of two planetary-mass bodies in the sdB + dM binary Kepler-451 system, the number of circumbinary planets in PCEBs approaches 30 now. However, some of these systems turned out to be dynamically unstable with the suggested planetary parameters. As more observations accumulate over time, there have been significant changes in both the number of suggested planets and their parameters. These necessitate a look back to the ETV analyses of these systems with new and more precise data spanning longer baselines. Within this contribution, we review the systems hosting substellar bodies suggested from the light-time effect they are claimed to be causing. We list the general problems encountered during the ETV analyses and the interpretation of the results, and comment on their possible solutions. We cal-culate and present the potentials of supporting evidence from astrometry, radial velocity, and transit observations as well as tests through dynamical stability analyses and magnetic activity assumptions.","PeriodicalId":35838,"journal":{"name":"Bulletin de la Societe Royale des Sciences de Liege","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135053151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Automatic extraction of build-up areas from bare land using Sentinel 2A imagery in El Khroub city, Algeria 阿尔及利亚El Khroub市使用Sentinel 2A图像从裸地自动提取堆积区域

Bulletin de la Societe Royale des Sciences de Liege Pub Date : 2023-01-01 DOI: 10.25518/0037-9565.11175

Ahmed Amine Tabet, Gihen Rym Abdaoui, Hafid Layeb

{"title":"Automatic extraction of build-up areas from bare land using Sentinel 2A imagery in El Khroub city, Algeria","authors":"Ahmed Amine Tabet, Gihen Rym Abdaoui, Hafid Layeb","doi":"10.25518/0037-9565.11175","DOIUrl":"https://doi.org/10.25518/0037-9565.11175","url":null,"abstract":"In this research work, the separation of built-up areas from bare lands in El Khroub city is carried out using a supervised classification approach involving several indices and combining spectral bands of the Sentinel-2A images sensor. The multi-index approach is based on the combination of seven indices in order to discriminate between the three main categories of land cover, which are water bodies, green areas and buildings. 3First, this operation requires the use of NDVI, BAEI, NDBI, NDTI, BUI, MNDWI and the NDVIre index, which have a strong discrimination capacity between build-up area and the other land cover features. The neo-images obtained from the combination of the above indices are then classified with the Likelihood algorithm for the extraction of the six class types of land cover (built-up areas, bare land, vegetation, forest, water bodies and asphalt). The multi-index obtained from the combination of BUI, NDTI and NDVIre is the most effective; shown by the evaluation values, where the Overall accuracy is of 96.44%, the Kappa Coefficient (K) of 95.72% and a User Accuracy for built-up class of the order of 100%, with a zero rate of commission. Therefore, the multi-index (BUI, NDTI and NDVIre) is retained for build-up area extraction due to its best discrimination capability.","PeriodicalId":35838,"journal":{"name":"Bulletin de la Societe Royale des Sciences de Liege","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135053155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The SALT survey of chemically-peculiar hot subdwarfs SALT对化学上特殊的热亚矮星的调查

Bulletin de la Societe Royale des Sciences de Liege Pub Date : 2023-01-01 DOI: 10.25518/0037-9565.11209

C. Simon Jeffery, Itumeleng Monageng, Brent Miszalski, Edward J. Snowdon, Laura J.A. Scott, Vincent M. Woolf, Matti Dorsh

引用次数: 0

Kepler, K2, and TESS observations: ensemble and comparative asteroseismology 开普勒，K2和TESS观测:集合和比较星震学

Bulletin de la Societe Royale des Sciences de Liege Pub Date : 2023-01-01 DOI: 10.25518/0037-9565.11266

M. D. REED, A. S. BARAN, R. H. ØSTENSEN, J. H. TELTING, C. S. JEFFERY

引用次数: 0