恒星活动和行星开普勒-30的旋转的多尺度行为

IF 27.8 1区物理与天体物理 Q1 ASTRONOMY & ASTROPHYSICS

The Astronomy and Astrophysics Review Pub Date : 2021-03-29 DOI:10.1051/0004-6361/202140287

D. B. de Freitas, Antonino Francesco Lanza, F. da Silva Gomes, M. L. das Chagas

{"title":"恒星活动和行星开普勒-30的旋转的多尺度行为","authors":"D. B. de Freitas, Antonino Francesco Lanza, F. da Silva Gomes, M. L. das Chagas","doi":"10.1051/0004-6361/202140287","DOIUrl":null,"url":null,"abstract":"Context. The Kepler-30 system consists of a G dwarf star with a rotation period of ∼16 days and three planets orbiting almost coplanar with periods ranging from 29 to 143 days. Kepler-30 is a unique target to study stellar activity and rotation in a young solar-like star accompanied by a compact planetary system. Aims. We use about 4 years of high-precision photometry collected by the Kepler mission to investigate the fluctuations caused by photospheric convection, stellar rotation, and starspot evolution as a function of the timescale. Our main goal is to apply methods for the analysis of timeseries to find the timescales of the phenomena that affect the light variations. We correlate those timescales with periodicities in the star as well as in the planetary system. Methods. We model the flux rotational modulation induced by active regions using spot modelling and apply the Multifractal Detrending Moving Average algorithm (MFDMA) in standard and multiscale versions for analysing the behaviour of variability and light fluctuations that can be associated with stellar convection and the evolution of magnetic fields on timescales ranging from less than 1 day up to about 35 days. The light fluctuations produced by stellar activity can be described by the multifractal Hurst index that provides a measure of their persistence. Results. The spot modeling indicates a lower limit to the relative surface differential rotation of ∆Ω/Ω ∼ 0.02 ± 0.01 and suggests a short-term cyclic variation in the starspot area with a period of ∼ 34 days, virtually close to the synodic period of 35.2 days of the planet Kepler-30b. By subtracting the two timeseries of the SAP and PDC Kepler pipelines, we reduce the rotational modulation and find a 23.1-day period close to the synodic period of Kepler-30c. This period also appears in the multifractal analysis as a crossover of the fluctuation functions associated with the characteristic evolutionary timescales of the active regions in Kepler-30 as confirmed by spot modelling. These procedures and methods may be greatly useful for analysing current TESS and future PLATO data.","PeriodicalId":785,"journal":{"name":"The Astronomy and Astrophysics Review","volume":"11 1","pages":""},"PeriodicalIF":27.8000,"publicationDate":"2021-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"Multiscale behaviour of stellar activity and rotation of the planet host Kepler-30\",\"authors\":\"D. B. de Freitas, Antonino Francesco Lanza, F. da Silva Gomes, M. L. das Chagas\",\"doi\":\"10.1051/0004-6361/202140287\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Context. The Kepler-30 system consists of a G dwarf star with a rotation period of ∼16 days and three planets orbiting almost coplanar with periods ranging from 29 to 143 days. Kepler-30 is a unique target to study stellar activity and rotation in a young solar-like star accompanied by a compact planetary system. Aims. We use about 4 years of high-precision photometry collected by the Kepler mission to investigate the fluctuations caused by photospheric convection, stellar rotation, and starspot evolution as a function of the timescale. Our main goal is to apply methods for the analysis of timeseries to find the timescales of the phenomena that affect the light variations. We correlate those timescales with periodicities in the star as well as in the planetary system. Methods. We model the flux rotational modulation induced by active regions using spot modelling and apply the Multifractal Detrending Moving Average algorithm (MFDMA) in standard and multiscale versions for analysing the behaviour of variability and light fluctuations that can be associated with stellar convection and the evolution of magnetic fields on timescales ranging from less than 1 day up to about 35 days. The light fluctuations produced by stellar activity can be described by the multifractal Hurst index that provides a measure of their persistence. Results. The spot modeling indicates a lower limit to the relative surface differential rotation of ∆Ω/Ω ∼ 0.02 ± 0.01 and suggests a short-term cyclic variation in the starspot area with a period of ∼ 34 days, virtually close to the synodic period of 35.2 days of the planet Kepler-30b. By subtracting the two timeseries of the SAP and PDC Kepler pipelines, we reduce the rotational modulation and find a 23.1-day period close to the synodic period of Kepler-30c. This period also appears in the multifractal analysis as a crossover of the fluctuation functions associated with the characteristic evolutionary timescales of the active regions in Kepler-30 as confirmed by spot modelling. These procedures and methods may be greatly useful for analysing current TESS and future PLATO data.\",\"PeriodicalId\":785,\"journal\":{\"name\":\"The Astronomy and Astrophysics Review\",\"volume\":\"11 1\",\"pages\":\"\"},\"PeriodicalIF\":27.8000,\"publicationDate\":\"2021-03-29\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"The Astronomy and Astrophysics Review\",\"FirstCategoryId\":\"4\",\"ListUrlMain\":\"https://doi.org/10.1051/0004-6361/202140287\",\"RegionNum\":1,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ASTRONOMY & ASTROPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Astronomy and Astrophysics Review","FirstCategoryId":"4","ListUrlMain":"https://doi.org/10.1051/0004-6361/202140287","RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}

引用次数: 1

摘要

上下文。开普勒-30系统由一颗自转周期约16天的G矮星和三颗几乎共面绕轨道运行的行星组成，周期从29天到143天不等。开普勒-30是一个独特的目标，用于研究一颗年轻的类太阳恒星的恒星活动和旋转，该恒星伴随着一个紧凑的行星系统。目标我们使用开普勒任务收集的大约4年的高精度光度测量来研究由光球对流、恒星旋转和星斑演化引起的波动作为时间尺度的函数。我们的主要目标是应用时间序列分析的方法来找到影响光变化的现象的时间尺度。我们将这些时间尺度与恒星和行星系统的周期性联系起来。方法。我们使用斑点建模对由活跃区域引起的通量旋转调制进行建模，并在标准和多尺度版本中应用多重分形去趋势移动平均算法(MFDMA)，用于分析与恒星对流和光波动有关的行为和光波动在不到1天到大约35天的时间尺度上的演化。恒星活动产生的光波动可以用多重分形赫斯特指数来描述，该指数提供了测量其持久性的方法。结果。黑子模型表明，相对地表自转差值的下限为∆Ω/Ω ~ 0.02±0.01，表明该星黑子区域存在周期为~ 34天的短期周期变化，几乎接近开普勒-30b行星35.2天的朔望周期。通过减去SAP和PDC开普勒管道的两个时间序列，我们减少了旋转调制，发现23.1天的周期接近开普勒-30c的朔星周期。这一时期也出现在多重分形分析中，作为与开普勒-30活跃区域的特征演化时间尺度相关的波动函数的交叉，这一点已被斑点模型证实。这些程序和方法可能对分析当前TESS和未来PLATO数据非常有用。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

查看原文本刊更多论文

Multiscale behaviour of stellar activity and rotation of the planet host Kepler-30

Context. The Kepler-30 system consists of a G dwarf star with a rotation period of ∼16 days and three planets orbiting almost coplanar with periods ranging from 29 to 143 days. Kepler-30 is a unique target to study stellar activity and rotation in a young solar-like star accompanied by a compact planetary system. Aims. We use about 4 years of high-precision photometry collected by the Kepler mission to investigate the fluctuations caused by photospheric convection, stellar rotation, and starspot evolution as a function of the timescale. Our main goal is to apply methods for the analysis of timeseries to find the timescales of the phenomena that affect the light variations. We correlate those timescales with periodicities in the star as well as in the planetary system. Methods. We model the flux rotational modulation induced by active regions using spot modelling and apply the Multifractal Detrending Moving Average algorithm (MFDMA) in standard and multiscale versions for analysing the behaviour of variability and light fluctuations that can be associated with stellar convection and the evolution of magnetic fields on timescales ranging from less than 1 day up to about 35 days. The light fluctuations produced by stellar activity can be described by the multifractal Hurst index that provides a measure of their persistence. Results. The spot modeling indicates a lower limit to the relative surface differential rotation of ∆Ω/Ω ∼ 0.02 ± 0.01 and suggests a short-term cyclic variation in the starspot area with a period of ∼ 34 days, virtually close to the synodic period of 35.2 days of the planet Kepler-30b. By subtracting the two timeseries of the SAP and PDC Kepler pipelines, we reduce the rotational modulation and find a 23.1-day period close to the synodic period of Kepler-30c. This period also appears in the multifractal analysis as a crossover of the fluctuation functions associated with the characteristic evolutionary timescales of the active regions in Kepler-30 as confirmed by spot modelling. These procedures and methods may be greatly useful for analysing current TESS and future PLATO data.

求助全文

通过发布文献求助，成功后即可免费获取论文全文。去求助

来源期刊

The Astronomy and Astrophysics Review 地学天文-天文与天体物理

CiteScore

45.00

自引率

0.80%

发文量

期刊介绍： The Astronomy and Astrophysics Review is a journal that covers all areas of astronomy and astrophysics. It includes subjects related to other fields such as laboratory or particle physics, cosmic ray physics, studies in the solar system, astrobiology, instrumentation, and computational and statistical methods with specific astronomical applications. The frequency of review articles depends on the level of activity in different areas. The journal focuses on publishing review articles that are scientifically rigorous and easily comprehensible. These articles serve as a valuable resource for scientists, students, researchers, and lecturers who want to explore new or unfamiliar fields. The journal is abstracted and indexed in various databases including the Astrophysics Data System (ADS), BFI List, CNKI, CNPIEC, Current Contents/Physical, Chemical and Earth Sciences, Dimensions, EBSCO Academic Search, EI Compendex, Japanese Science and Technology, and more.