TY - JOUR

T1 - HD 34736: an intensely magnetised double-lined spectroscopic binary with rapidly rotating chemically peculiar B-type components

AU - Semenko, E

AU - Kochukhov, O

AU - Mikulášek, Z

AU - Wade, G A

AU - Alecian, E

AU - Bohlender, D

AU - Das, B

AU - Feliz, D L

AU - Janík, J

AU - Kolář, J

AU - Krtička, J

AU - Kudryavtsev, D O

AU - Labadie-bartz, J M

AU - Mkrtichian, D

AU - Monin, D

AU - Petit, V

AU - Romanyuk, I I

AU - Shultz, M E

AU - Shulyak, D

AU - Siverd, R J

AU - Tkachenko, A

AU - Yakunin, I A

AU - Zejda, M

PY - 2024/11/15

Y1 - 2024/11/15

N2 - We report the results of a comprehensive study of the spectroscopic binary (SB2) system HD 34736 hosting two chemically peculiar (CP) late B-type stars. Using new and archival observational data, we characterize the system and its components, including their rotation and magnetic fields. Fitting of the radial velocities yields Porb = 83.d 219(3) and e = 0.8103(3). The primary component is a CP He-wk star with Teff A = 13000 ± 500 K and υe sin i = 75 ± 3 km s−1 , while the secondary exhibits variability of Mg and Si lines, and has Teff B = 11500 ± 1000 K and υe sin i = 110–180 km s−1 . Transiting Exoplanet SurveySatellite and Kilodegree Extremely Little Telescope photometry reveal clear variability of the primary component with a rotational period ProtA = 1.d 279 988 5(11), which is lengthening at a rate of 1.26(6) s yr−1 . For the secondary, ProtB = 0.d 522 693 8(5),reducing at a rate of −0.14(3) s yr−1 . The longitudinal component 〈Bz 〉 of the primary’s strongly asymmetric global magnetic field varies from −6 to +5 kG. Weak spectropolarimetric evidence of a magnetic field is found for the secondary star. Theobserved X-ray and radio emission of HD 34736 may equally be linked to a suspected T Tau-like companion or magnetospheric emission from the principal components. Given the presence of a possible third magnetically active body, one can propose thatthe magnetic characteristics of the protostellar environment may be connected to the formation of such systems

AB - We report the results of a comprehensive study of the spectroscopic binary (SB2) system HD 34736 hosting two chemically peculiar (CP) late B-type stars. Using new and archival observational data, we characterize the system and its components, including their rotation and magnetic fields. Fitting of the radial velocities yields Porb = 83.d 219(3) and e = 0.8103(3). The primary component is a CP He-wk star with Teff A = 13000 ± 500 K and υe sin i = 75 ± 3 km s−1 , while the secondary exhibits variability of Mg and Si lines, and has Teff B = 11500 ± 1000 K and υe sin i = 110–180 km s−1 . Transiting Exoplanet SurveySatellite and Kilodegree Extremely Little Telescope photometry reveal clear variability of the primary component with a rotational period ProtA = 1.d 279 988 5(11), which is lengthening at a rate of 1.26(6) s yr−1 . For the secondary, ProtB = 0.d 522 693 8(5),reducing at a rate of −0.14(3) s yr−1 . The longitudinal component 〈Bz 〉 of the primary’s strongly asymmetric global magnetic field varies from −6 to +5 kG. Weak spectropolarimetric evidence of a magnetic field is found for the secondary star. Theobserved X-ray and radio emission of HD 34736 may equally be linked to a suspected T Tau-like companion or magnetospheric emission from the principal components. Given the presence of a possible third magnetically active body, one can propose thatthe magnetic characteristics of the protostellar environment may be connected to the formation of such systems

KW - binaries: spectroscopic

KW - stars: chemically peculiar

KW - stars: magnetic fields

KW - techniques: polarimetric

UR - https://www.mendeley.com/catalogue/15725a8e-bfcc-326a-ad4c-6cc58062a2db/

U2 - 10.1093/mnras/stae2503

DO - 10.1093/mnras/stae2503

M3 - Article

VL - 535

SP - 2812

EP - 2836

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 3

ER -