scholarly journals Studies of Magnetic Chemically Peculiar Stars Using the 6-m Telescope at SAO RAS

Universe ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 465
Author(s):  
Iosif Romanyuk
Keyword(s):  
Magnetic Fields ◽  
Field Component ◽  
Rotation Period ◽  
Young Stars ◽  
Rotation Periods ◽  
Chemically Peculiar ◽  
Peculiar Stars ◽  
Magnetic Stars ◽  
Magnetic Model ◽  
Chemically Peculiar Stars

We present a survey of the most important results obtained in observations with the 6-m telescope in the studies of magnetic fields of chemically peculiar stars. It is shown that we have found more than 200 new magnetic chemically peculiar stars, which is more than 30% of their total known number. Observations of ultra-slow rotators (stars with rotation periods of years and decades) have shown that there are objects with strong fields among them, several kG in magnitude. In the association of young stars in Orion, it has been found that the occurrence and strength of magnetic fields of chemically peculiar stars decrease sharply with age in the interval from 2 to 10 Myr. These data indicate the fossil nature of magnetic fields of chemically peculiar stars. About 10 magnetic stars were found based on ultra-accurate photometry data obtained from the Kepler and TESS satellites. A new effective method of searching for magnetic stars was developed. In addition, the exact rotation periods make it possible to build reliable curves of the longitudinal field component variability with the phase of the star’s rotation period, and hence to create its magnetic model. The survey is dedicated to the memory of Prof. Yuri Nikolaevich Gnedin.

scholarly journals A Magnetic Snapshot Survey of F-Type Stars

2020 ◽  
Author(s):  
J M Seach ◽  
S C Marsden ◽  
B D Carter ◽  
C Neiner ◽  
C P Folsom ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Longitudinal Magnetic Field ◽  
Convection Zone ◽  
Stellar Radius ◽  
Spectral Class ◽  
Chemically Peculiar ◽  
Peculiar Stars ◽  
The Mean ◽  
Chemically Peculiar Stars ◽  
F Stars

Abstract We present a spectropolarimetric magnetic snapshot survey of 55 stars which includes 53 F-type stars ranging from spectral types F0 to F9 plus 2 chemically peculiar stars β CrB, and δ Cap. We look for magnetic fields in stars spanning a range of effective temperatures where the transition from fossil to dynamo magnetic fields is believed to occur. High-resolution spectropolarimetry using circularly polarized spectra is used to look for a magnetic detection in the Stokes V profile, determine the mean longitudinal magnetic field (Bl), and to look for correlations with stellar parameters. Surface magnetic fields are detected on 14 F-stars, and present in every spectral class from F3V-F9V ranging in strength from 0.3 ± 0.1 G (36 UMa, F8V) to 8.3 ± 0.9 G (h Dra, F8V). Thus we find photospheric magnetic fields are present in stars as early as spectral type F3V with an outer convection zone thickness less than a few per cent of the stellar radius.

scholarly journals The Origin and Structure of the Magnetic Fields of the Chemically Peculiar Stars

1986 ◽  
Vol 90 ◽  
pp. 1-10
Author(s):  
David Moss
Keyword(s):  
Magnetic Fields ◽  
Internal Structure ◽  
Time Dependent ◽  
Dynamo Theory ◽  
Current Time ◽  
Chemically Peculiar ◽  
Peculiar Stars ◽  
Theoretical Predictions ◽  
Chemically Peculiar Stars ◽  
Coherent Picture

AbstractRival theories for the origin of the magnetic fields present in the CP stars are discussed, particular attention being paid to the claims of the ‘contemporary dynamo’ and ‘fossil’ theories. The internal structure of the field as predicted by calculations consistent with the fossil theory is discussed at length. It seems that current time dependent models can now give a coherent picture of the fields of the CP stars according to the fossil theory. Dynamo theory modelling has not been developed in such detail. As yet neither the theoretical predictions nor the observational material seem to be detailed enough to allow a decisive comparison between the theories.

scholarly journals Working Group on Ap and Related Stars: (Groupe de Travail Pour Les Etoiles Particulieres de Type a)

2000 ◽  
Vol 24 (1) ◽  
pp. 249-250
Author(s):  
Masahide Takada-Hidai ◽  
Georges Alecian ◽  
Richard O. Gray ◽  
Marco Landolfi ◽  
Pierre North ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Working Group ◽  
Diffusion Processes ◽  
Type A ◽  
Atomic Data ◽  
Large Telescope ◽  
Chemically Peculiar ◽  
Peculiar Stars ◽  
Chemically Peculiar Stars

The JD 16 was held on August 25, 1997 as one-day session with the title of “Spectroscopy with Large Telescope of Chemically Peculiar Stars”. It was supported by the Division IV and Commissions 14, 27, 29, 36, and 45.The members of SOC were: G. Alecian, J. Babel, M. Gerbaldi, R. O. Gray, G. Mathys, P. North, M. Takada-Hidai (Chairperson), and J. Zverko (Co-chairperson).15 talks and 18 contributed posters were presented on six topics of (1) model atmospheres and atomic data, (2) stellar parameters, (3) LTE and NLTE abundance analyses, (4) diffusion processes, (5) magnetic fields, and (6) variabilities. Approximate number of participants amounted to 50 at maximum.

scholarly journals Detection of magnetic fields in chemically peculiar stars observed with the K2 space mission

2018 ◽  
Vol 478 (2) ◽  
pp. 2777-2793 ◽  
Author(s):  
B Buysschaert ◽  
C Neiner ◽  
A J Martin ◽  
C Aerts ◽  
D M Bowman ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Space Mission ◽  
Chemically Peculiar ◽  
Peculiar Stars ◽  
Chemically Peculiar Stars

scholarly journals Investigations of the Magnetic Fields of Chemically Peculiar Stars of Different Age

1986 ◽  
Vol 90 ◽  
pp. 29-32
Author(s):  
Yu.V. Glagolevskij ◽  
V.G. Klochkova ◽  
I.M. Kopylov
Keyword(s):  
Magnetic Fields ◽  
Open Clusters ◽  
Special Astrophysical Observatory ◽  
Open Clusters And Associations ◽  
Origin And Evolution ◽  
Chemically Peculiar ◽  
Peculiar Stars ◽  
Chemically Peculiar Stars ◽  
Stellar Magnetic Fields

The program of comprehensive investigations of stellar magnetism in the Special Astrophysical Observatory of the USSR AS includes the study of origin and evolution of the stellar magnetic fields in open clusters and associations of different age. In the papers by Borra (1981), Brown et al. (1981) and North and Cramer (1984) have been found some indications on the evolutionary decay of the fossil stellar fields.

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