2018A&A...615A..81N


Query : 2018A&A...615A..81N

2018A&A...615A..81N - Astronomy and Astrophysics, volume 615A, 81-81 (2018/7-1)

Applegate mechanism in post-common-envelope binaries: Investigating the role of rotation.

NAVARRETE F.H., SCHLEICHER D.R.G., FUENTEALBA J.Z. and VOLSCHOW M.

Abstract (from CDS):


Context. Eclipsing time variations are observed in many close binary systems. In particular, for several post-common-envelope binaries (PCEBs) that consist of a white dwarf and a main sequence star, the observed-minus-calculated (O-C) diagram suggests that real or apparent orbital period variations are driven by Jupiter-mass planets or as a result of magnetic activity, the so-called Applegate mechanism. The latter explains orbital period variations as a result of changes in the stellar quadrupole moment due to magnetic activity.
Aims. In this work we explore the feasibility of driving eclipsing time variations via the Applegate mechanism for a sample of PCEB systems, including a range of different rotation rates.
Methods. We used the MESA code to evolve 12 stars with different masses and rotation rates. We applied simple dynamo models to their radial profiles to investigate the scale at which the predicted activity cycle matches the observed modulation period, and quantifiy the uncertainty. We further calculated the required energies to drive the Applegate mechanism.
Results. We show that the Applegate mechanism is energetically feasible in 5 PCEB systems. In RX J2130.6+4710, it may be feasible as well considering the uncertainties. We note that these are the systems with the highest rotation rate compared to the critical rotation rate of the main-sequence star.
Conclusions. The results suggest that the ratio of physical to critical rotation rate in the main sequence star is an important indicator for the feasibility of Applegate's mechanism, but exploring larger samples will be necessary to probe this hypothesis.

Abstract Copyright: © ESO 2018

Journal keyword(s): dynamo - stars: activity - binaries: close - stars: low-mass - stars: rotation

Simbad objects: 13

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Number of rows : 13
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 V* UZ For CV* 03 35 28.6518733656 -25 44 21.768755424           M4.5 256 0
2 HD 22468 RS* 03 36 47.2911034958 +00 35 15.938962144 7.09 6.79 5.90 5.4   K2:Vnk 1151 0
3 V* V471 Tau EB* 03 50 24.9666549840 +17 14 47.430910716   10.258 9.373   8.393 K2V+DA 644 0
4 V* RR Cae WD* 04 21 05.5631820426 -48 39 07.061113433 14.50 14.92 14.40     DA7.8 144 1
5 V* V470 Cam HS* 07 10 42.0513241680 +66 55 43.521505680           sdB+dM 103 1
6 V* DP Leo CV* 11 17 15.9239894616 +17 57 41.690453220           ~ 218 1
7 BD-07 3477 HS* 12 44 20.2386233232 -08 40 16.846099536   10.46 10.594 10.895   sdB2VIIHe3 269 1
8 V* NY Vir HS* 13 38 48.1466908176 -02 01 49.207286748   13.43 13.66 13.75   sdB1VIIHe1 208 1
9 V* QS Vir EB* 13 49 52.0029035208 -13 13 37.000132212 14.27 14.98 14.40 14.37   DA3+dM 127 1
10 V* NN Ser CV* 15 52 56.1203524080 +12 54 44.429312196     16.51     DAO1+M4 254 0
11 V* V1828 Aql HS* 20 20 00.4587151080 +04 37 56.517736296   12.9   13.34   sdOB+dM 64 1
12 V* HU Aqr CV* 21 07 58.1944529400 -05 17 40.557671916   16.198 15.814 14.891   D+M4V 264 1
13 RX J2130.6+4710 XB* 21 30 18.4670033976 +47 10 07.403693592           DA+M3.5/4Ve 31 0

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2022.09.30-22:29:51

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