Detailed Information on Publication Record
2007
Orbital period changes of the nova-like cataclysmic variable AC Cancri: evidence of magnetic braking and an unseen companion
QIAN, Shengbang, Z.-B. DAI, J.-J. HE, J. Z. YUAN, F. Y. XIANG et. al.Basic information
Original name
Orbital period changes of the nova-like cataclysmic variable AC Cancri: evidence of magnetic braking and an unseen companion
Name in Czech
Změny orbitální periody nově podobné kataklyzmické proměnné hvězdy AC Cancri: důkaz magnetického brždění a neviditelné složky
Authors
QIAN, Shengbang (156 China), Z.-B. DAI (156 China), J.-J. HE (156 China), J. Z. YUAN (156 China), F. Y. XIANG (156 China) and Miloslav ZEJDA (203 Czech Republic, guarantor)
Edition
Astronomy and Astrophysics, 2007, 0004-6361
Other information
Language
English
Type of outcome
Článek v odborném periodiku
Field of Study
10308 Astronomy
Country of publisher
France
Confidentiality degree
není předmětem státního či obchodního tajemství
References:
Impact factor
Impact factor: 4.259
RIV identification code
RIV/00216224:14310/07:00029084
Organization unit
Faculty of Science
UT WoS
000245686800021
Keywords in English
nova; cataclysmic variables; eclipsing binaries;AC Cnc; evolution; mass loss
Tags
International impact, Reviewed
Změněno: 24/6/2009 13:07, doc. RNDr. Miloslav Zejda, Ph.D.
V originále
Aims.The source AC Cnc is a nova-like cataclysmic variable containing a white-dwarf primary with a mass of 0.76 Mo and a K2-type secondary with a mass of 0.77 Mo. We intend to study its period changes and search for evidence of magnetic braking and unseen third body. Methods: The period changes were investigated based on the analysis of the O-C curve, which is formed by one new eclipse time together with the others compiled from the literature. Results: A cyclic change with a period of 16.2 yr was found to be superimposed on a long-term period decrease at a rate of dot{P}=-1.24(0.44).{10-8} days/year. Conclusions: It is shown that the mechanism of magnetic activity-driven changes in the quadrupole momentum of the secondary star (Applegate's mechanism) does not explain it easily. This period oscillation was plausibly interpreted by a light-travel time effect caused by the presence of a cool M-type dwarf companion (M_3<0.097 Mo) in a long orbit (16.2 yr) around the binary. Since the masses of both components are nearly the same, the mass transfer from the lobe-filling secondary to the primary is not efficient to cause the continuous period decrease. It may be strong evidence of an enhanced magnetic stellar wind from the K2-type component. If the Alfén radius of the cool secondary is the same as that of the Sun (i.e., RA = 15 Ro), the mass-loss rate should be dot{M_2}=-1.65.{10-10} Mo/year. By using the enhanced mass loss proposed by Tout and Eggleton (1988), the mass-loss rate should be dot{M_2}=-1.18.{10-9} Mo/year. In this case, the Alfén radius is determined to be RA = 5.2 Ro. However, the long-term decrease of the period may be only a part of a long-period (<100 yr) oscillation caused by the presence of an additional body. To check the conclusions, new precise times of light minimum will be required.
In Czech
Změny orbitální periody nově podobné kataklyzmické proměnné hvězdy AC Cancri: důkaz magnetického brždění a neviditelné složky
Links
| GA205/04/2063, research and development project |
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