Observing the changing surface structures of the active K giant sigma Geminorum with SONG | |
Korhonen, H.1; Roettenbacher, R. M.2; Gu SH(顾盛宏)3,4,5![]() | |
Source Publication | ASTRONOMY & ASTROPHYSICS
![]() |
2021-02-01 | |
Volume | 646Pages:11 |
DOI | 10.1051/0004-6361/202038799 |
Contribution Rank | 第3完成单位 |
Indexed By | SCI |
Keyword | stars: activity stars: late-type stars: rotation starspots stars: individual: sigma Geminorum |
Abstract | Aims. We aim to study the spot evolution and differential rotation in the magnetically active cool K-type giant star sigma Gem from broadband photometry and continuous spectroscopic observations that span 150 nights.Methods. We use high-resolution, high signal-to-noise ratio spectra obtained with the Hertzsprung SONG telescope to reconstruct surface (photospheric) temperature maps with Doppler imaging techniques. The 303 observations span 150 nights and allow for a detailed analysis of the spot evolution and surface differential rotation. The Doppler imaging results are compared to simultaneous broadband photometry from the Tennessee State University T3 0.4 m Automated Photometric Telescope. The activity from the stellar chromosphere, which is higher in the stellar atmosphere, is also studied using SONG observations of Balmer H alpha line profiles and correlated with the photospheric activity.Results. The temperature maps obtained during eight consecutive stellar rotations show mainly high-latitude or polar spots, with the main spot concentrations above latitude 45 degrees. The spots concentrate around phase 0.25 near the beginning of our observations and around phase 0.75 towards the end. The photometric observations confirm a small jump in spot phases that occurred in February 2016. The cross-correlation of the temperature maps reveals rather strong solar-like differential rotation, giving a relative surface differential rotation coefficient of alpha = 0.10 +/- 0.02. There is a weak correlation between the locations of starspots and enhanced emission in the chromosphere at some epochs. |
Funding Project | Yale Center for Astronomy & Astrophysics (YCAA) Prize Postdoctoral Fellowship ; National Natural Science Foundation of China[10373023] ; National Natural Science Foundation of China[10773027] ; National Natural Science Foundation of China[11333006] ; National Natural Science Foundation of China[U1531121] ; NASA ; NSF ; Tennessee State University ; State of Tennessee Centers of Excellence program ; VILLUM FONDEN[00028173] ; Danish National Research Foundation[DNRF106] |
Funding Organization | Yale Center for Astronomy & Astrophysics (YCAA) Prize Postdoctoral Fellowship ; National Natural Science Foundation of China[10373023, 10773027, 11333006, U1531121] ; NASA ; NSF ; Tennessee State University ; State of Tennessee Centers of Excellence program ; VILLUM FONDEN[00028173] ; Danish National Research Foundation[DNRF106] |
Language | 英语 |
Subject Area | 天文学 ; 恒星与银河系 ; 恒星天文学 ; 恒星形成与演化 |
MOST Discipline Catalogue | 理学 ; 理学::天文学 |
Subtype | Article |
Publisher | EDP SCIENCES S A |
Publication Place | 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE |
ISSN | 0004-6361 |
URL | 查看原文 |
WOS ID | WOS:000616488000001 |
WOS Research Area | Astronomy & Astrophysics |
WOS Subject | Astronomy & Astrophysics |
WOS Keyword | FK COMAE BERENICES ; DIFFERENTIAL ROTATION ; FLIP-FLOP ; STARS ; LONGITUDES ; CYCLES ; SPOT ; SPECTROSCOPY ; ANDROMEDAE ; FLARE |
Citation statistics | |
Document Type | 期刊论文 |
Identifier | http://ir.ynao.ac.cn/handle/114a53/24189 |
Collection | 系外行星研究组 中国科学院天体结构与演化重点实验室 |
Corresponding Author | Korhonen, H. |
Affiliation | 1.European Southern Observ ESO, Alonso de Cordova 3107, Santiago, Chile 2.Yale Univ, Dept Phys, Yale Ctr Astron & Astrophys, New Haven, CT 06520 USA 3.Chinese Acad Sci, Yunnan Observ, Kunming 650216, Yunnan, Peoples R China 4.Chinese Acad Sci, Key Lab Struct & Evolut Celestial Objects, Kunming 650216, Yunnan, Peoples R China 5.Univ Chinese Acad Sci, Sch Astron & Space Sci, Beijing 101408, Peoples R China 6.Aarhus Univ, Dept Phys & Astron, Stellar Astrophys Ctr, Ny Munkegade 120, DK-8000 Aarhus C, Denmark 7.Tennessee State Univ, Ctr Excellence Informat Syst, Nashville, TN 37209 USA 8.Tech Univ Denmark, Natl Space Inst, DTU Space, Elektrovej 328, DK-2800 Lyngby, Denmark 9.Inst Astrofis Canarias, Tenerife 38205, Spain 10.Univ La Laguna, Dept Astrofis, Tenerife 38206, Spain |
Recommended Citation GB/T 7714 | Korhonen, H.,Roettenbacher, R. M.,Gu SH,et al. Observing the changing surface structures of the active K giant sigma Geminorum with SONG[J]. ASTRONOMY & ASTROPHYSICS,2021,646:11. |
APA | Korhonen, H..,Roettenbacher, R. M..,Gu SH.,Grundahl, F..,Andersen, M. F..,...&Palle, P. L..(2021).Observing the changing surface structures of the active K giant sigma Geminorum with SONG.ASTRONOMY & ASTROPHYSICS,646,11. |
MLA | Korhonen, H.,et al."Observing the changing surface structures of the active K giant sigma Geminorum with SONG".ASTRONOMY & ASTROPHYSICS 646(2021):11. |
Files in This Item: | There are no files associated with this item. |
Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Edit Comment