{"title":"A Search for Low-amplitude Periodic Brightness Variations in HD 168 443","authors":"N. I. Bondar’, A. A. Shlyapnikov","doi":"10.1134/S0016793223080054","DOIUrl":null,"url":null,"abstract":"<p>The paper presents the results of studying light curves of the star HD 168443 obtained from the ground-based and space photometric observations within the ASAS, KWS surveys, and the <i>Hipparcos</i> mission from 1990 to 2020. During 30 years of observations, the average annual brightness of the star remained constant within the measurement errors, the mean <i>V</i>-value was 6<sup>m</sup>.96. Using the dense data series in 2007–2009, the photometric period of 34.7 days was found, and the low-amplitude brightness variability was studied with this period. We determined epochs and amplitude of rotational modulation produced by the development of active regions. These parameters do not change during 2–5 rotations of the star. The amplitude of the rotational modulation increases in 2007 before the epoch of maximum brightness. The star was the brightest in 2009, its <i>V</i>-magnitude was 6<sup>m</sup>.92. The location of starspots on the surface of the star during these epochs is also considered.</p>","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"63 8","pages":"1277 - 1284"},"PeriodicalIF":0.7000,"publicationDate":"2024-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geomagnetism and Aeronomy","FirstCategoryId":"89","ListUrlMain":"https://link.springer.com/article/10.1134/S0016793223080054","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
The paper presents the results of studying light curves of the star HD 168443 obtained from the ground-based and space photometric observations within the ASAS, KWS surveys, and the Hipparcos mission from 1990 to 2020. During 30 years of observations, the average annual brightness of the star remained constant within the measurement errors, the mean V-value was 6m.96. Using the dense data series in 2007–2009, the photometric period of 34.7 days was found, and the low-amplitude brightness variability was studied with this period. We determined epochs and amplitude of rotational modulation produced by the development of active regions. These parameters do not change during 2–5 rotations of the star. The amplitude of the rotational modulation increases in 2007 before the epoch of maximum brightness. The star was the brightest in 2009, its V-magnitude was 6m.92. The location of starspots on the surface of the star during these epochs is also considered.
期刊介绍：
Geomagnetism and Aeronomy is a bimonthly periodical that covers the fields of interplanetary space; geoeffective solar events; the magnetosphere; the ionosphere; the upper and middle atmosphere; the action of solar variability and activity on atmospheric parameters and climate; the main magnetic field and its secular variations, excursion, and inversion; and other related topics.
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号
