Covariations of chromospheric and photometric variability of the young Sun analogue HD 30495: evidence for and interpretation of mid-term periodicities

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F19%3A00497495" target="_blank" >RIV/67985530:_____/19:00497495 - isvavai.cz</a>

Result on the web

<a href="https://academic.oup.com/mnras/article/483/2/2748/5228758" target="_blank" >https://academic.oup.com/mnras/article/483/2/2748/5228758</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/mnras/sty3290" target="_blank" >10.1093/mnras/sty3290</a>

Result language

angličtina

Original language name

Covariations of chromospheric and photometric variability of the young Sun analogue HD 30495: evidence for and interpretation of mid-term periodicities

Original language description

This study reports the synchronization between the chromospheric and photometric variability at time-scale of about 1.6-1.8 yr as observed for the young, rapidly rotating solar analogue HD 30495. In addition, HD 30495 may be presenting evidence of surface differential rotation at time-scales of about 11 d and 21 d, as well as the sunspot-like decadal cycles at 11-12 yr or so. We apply a new gapped wavelet method of time-frequency analysis for studying the variability in a new composite of the chromospheric S-index (1967-2018) and the longest photometric Delta(b + y)/2 index (1993-2018). We discuss and interpret our results in relation to other observed mid-term periodicities roughly of the same time-scales that had been found recently from not only chromospheric and photospheric activity indices but also from coronal X-ray emissions as observed in a considerably large set of stellar samples including those young Sun analogues from the Kepler satellite project. Thus, there is an apparent universality of such mid-term activity modulation time-scales as this solar-stellar magnetic phenomenon is well observed directly for a host of solar activity related indices covering the photopsheric, chromospheric, coronal, and even the heliospheric (utilizing the measures of incoming galactic cosmic rays as a probe of activity variations) activity records. This is why we made a further attempt to interpret the results in search of a realistic generation mechanism as well as spatio-temporal persistency of the phenomenon under a wide scenario of dynamo simulations.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Monthly Notices of the Royal Astronomical Society

ISSN

0035-8711

e-ISSN

—

Volume of the periodical

483

Issue of the periodical within the volume

2

Country of publishing house

GB - UNITED KINGDOM

Number of pages

10

Pages from-to

2748-2757

UT code for WoS article

000462258200098

EID of the result in the Scopus database

2-s2.0-85065209532