J/other/AstBu/67.44 Speckle interferometry of Ap stars (Balega+, 2012)
Speckle interferometry of magnetic stars with the BTA. I. First results.
Balega Yu.Yu., Dyachenko V.V., Maksimov A.F., Malogolovets E.V.,
Rastegaev D.A., Romanyuk I.I.
≪Astrophys. Bull., 67, 44 (2012)>
=2012AstBu..67...44B 2012AstBu..67...44B
ADC_Keywords: Positional data ; Stars, Ap ; Stars, Bp ; Stars, peculiar ;
Stars, A-type ; Stars, B-type ; Stars, double and multiple ;
Interferometry
Keywords: stars: magnetic - stars: binaries -
methods: observational: speckle interferometry
Abstract:
We present the results of speckle interferometry of a sample of 117
chemically peculiar stars with global magnetic fields. The
observations were made in December 2009 at the BTA with a spatial
resolution of about 0.02 arcseconds in the visual spectral region.
Twenty-nine stars were resolved into individual components, 14 of them
for the first time (HD965, HD5797, HD8855, HD10783, HD16605, HD21699,
HD35502, HD51418, HD64486, HD79158, HD103498, HD108651, HD213918,
HD293764). In twelve cases a companion turned out to be 2-4 magnitudes
fainter than the main component - a magnetic star. Young hot Bp
stars HD35502 and HD213918 are exceptions, since their companions are
fainter by about 1 magnitude. In all cases, the linear distance from a
star to its companion at the epoch of observations in the picture
plane exceeded 109km. Eighty-eight magnetic CP stars revealed no
secondary components within our study. Thus, the fraction of speckle
interferometric binaries in our sample amounts to 25%.
Description:
The results of our measurements of 27 binary systems, resolved into
components are presented in Table 1, where the stars are laid out in
the ascending order by their Right Ascensions. The table columns
contain the following data: the number of the star in the HD catalog,
its number in the HIPPARCOS catalog, its WDS designation (2000.0
coordinates), the epoch of observations, companion's position angle
θ and its error σ_θ, the separation between the
components ρ and the error of this value σ_ρ in
milliarcseconds (mas), the brightness difference between the
components Δm and the error of this value σ_Δm, the
spectral range used λ.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 92 50 Positional parameters for 27 binary systems with
magnetic Ap/Bp primary components
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See also:
J/other/AstBu/69.269 : Paper II. 2010-2012 observations (Rastegaev+, 2014)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- --- [HD]
4- 9 I6 --- HD HD identification number
12- 14 A3 --- --- [HIP]
16- 21 I6 --- HIP ? HIPPARCOS identification number
23- 32 A10 --- WDS WDS designation (based on J2000 position) (2)
34- 40 A7 --- Disc Discoverer designation (from WDS)
41- 45 A5 --- Comp Components when more than 2 (from WDS)
47- 56 F10.5 yr Epoch [2009.92/2009.93] Besselian year of observations
58- 62 F5.1 deg theta [0/360]? Companion's position angle θ
64- 66 F3.1 deg e_theta [0.3/6.4] Error of theta
68- 71 I4 mas rho [16/4291] Separation between the components ρ
73- 74 I2 mas e_rho [1/22] Error of rho
76- 79 F4.2 mag Dm [0/5]? Magnitude difference between the
components Δm (1)
81- 84 F4.2 mag e_Dm [0.01/0.2]? Error of Dm
86- 92 A7 nm Band 550/20 or 800/100 band
(central wavelength/bandwidth)
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Note (1): The brightness difference between components of wide pairs
(>4-arcsec) is not presented because it can not be measured due to the
speckle image clipping by the detector frame window.
Note (2): New WDS designations added after publication for systems resolved
for the first time.
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Acknowledgements:
Denis Rastegaev, leda(at)sao.ru
References:
Rastegaev et al., Paper II, 2014AstBu..69..296R 2014AstBu..69..296R, Cat. J/other/AstBu/69.296
(End) Denis Rastegaev [SAO, Russia], Patricia Vannier [CDS] 01-Apr-2015