The V471 Tauri System: A Multi-Data-Type Probe

Vaccaro, T. R.; Wilson, R. E.; Hamme, W. Van; Terrell, Dirk

doi:10.1088/0004-637x/810/2/157

Cited by 36 publications

(58 citation statements)

References 75 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this respect, the proposed brown dwarf in V471 Tau has not been found via direct imaging (Hardy et al 2015; but see comments by Vaccaro et al 2015). In this paper, we in fact show that the period time variations in V471 Tau could also be produced by an Applegate mechanism.…”

Section: Introductionmentioning

confidence: 57%

Eclipsing time variations in close binary systems: Planetary hypothesis vs. Applegate mechanism

Völschow

Schleicher

Perdelwitz

et al. 2016

A&A

View full text Add to dashboard Cite

The observed eclipsing time variations in post-common-envelope binaries (PCEBs) can be interpreted as potential evidence for massive Jupiter-like planets, or as a result of magnetic activity, leading to quasi-periodic changes in the quadrupole moment of the secondary star. The latter is commonly referred to as the Applegate mechanism. We employ an improved version of Applegate's model including the angular momentum exchange between a finite shell and the core of the star. The framework is employed to derive the general conditions under which the Applegate mechanism can work, and is subsequently applied to a sample of 16 close binary systems with potential planets, including eleven PCEBs. Further, we present a detailed derivation and study of analytical models that allow for an straightforward extension to other systems. Using our full numerical framework, we show that the Applegate mechanism can clearly explain the observed eclipsing time variations in four of the systems, while the required energy to produce the quadrupole moment variations is too high in at least eight systems. In the remaining four systems, the required energy is comparable to the available energy produced by the stars, which we consider borderline cases. Therefore, the Applegate mechanism cannot uniquely explain the observed period time variations for this entire population. Even in systems where the required energy is too high, the Applegate mechanism may provide an additional scatter, which needs to be considered in the derivation and analysis of planetary models.

show abstract

Section: Introductionmentioning

confidence: 57%

Eclipsing time variations in close binary systems: Planetary hypothesis vs. Applegate mechanism

Völschow

Schleicher

Perdelwitz

et al. 2016

A&A

View full text Add to dashboard Cite

show abstract

“…V471 Tau (Guinan & Ribas 2001) and SDSS J143547 (Qian et al 2016). Also note that the brown dwarf companion in V471 Tau was excluded by Hardy et al (2015) but a new study agrees with the presence of a brown dwarf companion (Vaccaro et al 2015). Moreover, some possible planets orbiting the eclipsing CVs or pre-CVs were also presented such as V893 Sco (Bruch 2014), V2051 Oph , OY Car , DP Leo Beuermann et al 2011), HU Aqr (Qian et al 2011;Goździewski et al 2015), UZ For Potter et al 2011) and NN Ser (Marsh et al 2014).…”

Section: Discussionmentioning

confidence: 71%

Cyclic Period Oscillation of the Eclipsing Dwarf Nova DV UMa

Han

Qian

Voloshina

et al. 2017

View full text Add to dashboard Cite

DV UMa is an eclipsing dwarf nova with an orbital period of ∼ 2.06 h, which lies just at the bottom edge of the period gap. To detect its orbital period changes we present 12 new mid-eclipse times by using our CCD photometric data and archival data. Combining with the published mid-eclipse times in quiescence, spanning ∼ 30 yr, the latest version of the O − C diagram was obtained and analyzed. The best fit to those available eclipse timings shows that the orbital period of DV UMa is undergoing a cyclic oscillation with a period of 17.58(±0.52) yr and an amplitude of 71.1(±6.7) s. The periodic variation most likely arises from the light-travel-time effect via the presence of a circumbinary object because the required energy to drive the Applegate mechanism is too high in this system. The mass of the unseen companion was derived as M 3 sin i ′ = 0.025(±0.004)M ⊙ . If the third body is in the orbital plane (i.e. i ′ = i = 82.9• ) of the eclipsing pair, it would match to a brown dwarf. This hypothetical brown dwarf is orbiting its host star at a separation of ∼ 8.6 AU in an eccentric orbit (e = 0.44).

show abstract

“…Given the known age of the system, and the masses of the binary and the CB candidate, direct detection of such tertiary body should have been well within the capabilities of the instrument. Hardy et al (2015), however, report a null detection, casting doubt on the interpretation of the measured ETV signal (but see Vaccaro et al (2015) for alternative explanation). Nevertheless, based on our results for the dynamical survivability of CBPs around evolving binary stars, and on estimates of the occurrence rates of planets orbiting short-period MS binary stars (e.g.…”

Section: Discussionmentioning

confidence: 99%

Tatooine’s Future: The Eccentric Response of Kepler’s Circumbinary Planets to Common-Envelope Evolution of Their Host Stars

Kostov

Moore

Tamayo

et al. 2016

ApJ

View full text Add to dashboard Cite

Inspired by the recent Kepler discoveries of circumbinary planets orbiting nine close binary stars, we explore the fate of the former as the latter evolve off the main sequence. We combine binary star evolution models with dynamical simulations to study the orbital evolution of these planets as their hosts undergo common-envelope stages, losing in the process a tremendous amount of mass on dynamical timescales. Five of the systems experience at least one Roche-lobe overflow and common-envelope stages (Kepler-1647 experiences three), and the binary stars either shrink to very short orbits or coalesce; two systems trigger a double-degenerate supernova explosion. Kepler's circumbinary planets predominantly remain gravitationally bound at the end of the common-envelope phase, migrate to larger orbits, and may gain significant eccentricity; their orbital expansion can be more than an order of magnitude and can occur over the course of a single planetary orbit. The orbits these planets can reach are qualitatively consistent with those of the currently known post-commonenvelope, eclipse-time variations circumbinary candidates. Our results also show that circumbinary planets can experience both modes of orbital expansion (adiabatic and -2 -non-adiabatic) if their host binaries undergo more than one common-envelope stage; multiplanet circumbinary systems like Kepler-47 can experience both modes during the same common-envelope stage. Additionally, unlike Mercury orbiting the Sun, a circumbinary planet with the same semi-major axis can survive the common envelope evolution of a close binary star with a total mass of 1 M .

show abstract

The V471 Tauri System: A Multi-Data-Type Probe

Cited by 36 publications

References 75 publications

Eclipsing time variations in close binary systems: Planetary hypothesis vs. Applegate mechanism

Eclipsing time variations in close binary systems: Planetary hypothesis vs. Applegate mechanism

Cyclic Period Oscillation of the Eclipsing Dwarf Nova DV UMa

Tatooine’s Future: The Eccentric Response of Kepler’s Circumbinary Planets to Common-Envelope Evolution of Their Host Stars

Contact Info

Product

Resources

About