Mira Variables explained by a planetary companion interaction: A means to drop the pulsation paradigm?

Berlioz-Arthaud, Paul

doi:10.1051/0004-6361:20021540

Cited by 5 publications

(5 citation statements)

References 44 publications

(57 reference statements)

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“…We assume an initial position of pulsation of R 0 = 0.9 R 1 . This value is chosen because pulsations in AGB stars are believed to be driven in the hydrogen-ionization zone, located approximately at 0.1 − 0.2 R 1 below the photosphere (Berlioz-Arthaud 2003;Fadeyev 2016). ∆u = 5 km s −1 and P = 300 d are the constant velocity amplitude and period of the pulsations, respectively.…”

Section: Numerical Approach For the Primary Starmentioning

confidence: 99%

AGB winds in interacting binary stars

Bermúdez-Bustamante

Garcı́a-Segura

Steffen

et al. 2020

Monthly Notices of the Royal Astronomical Society

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We perform numerical simulations to investigate the stellar wind from interacting binary stars. Our aim is to find analytical formulae describing the outflow structure. In each binary system the more massive star is in the asymptotic giant branch and its wind is driven by a combination of pulsations in the stellar surface layers and radiation pressure on dust, while the less massive star is in the main sequence. Time averages of density and outflow velocity of the stellar wind are calculated and plotted as profiles against distance from the centre of mass and colatitude angle. We find that mass is lost mainly through the outer Lagrangian point L 2 . The resultant outflow develops into a spiral at low distances from the binary. The outflowing spiral is quickly smoothed out by shocks and becomes an excretion disk at larger distances. This leads to the formation of an outflow structure with an equatorial density excess, which is greater in binaries with smaller orbital separation. The pole-to-equator density ratio reaches a maximum value of ∼ 10 5 at Roche-Lobe Overflow state. We also find that the gas stream leaving L 2 does not form a circumbinary ring for stellar mass ratios above 0.78, when radiation pressure on dust is taken into account. Analytical formulae are obtained by curve fitting the 2-dimensional, azimuthally averaged density and outflow velocity profiles. The formulae can be used in future studies to setup the initial outflow structure in hydrodynamic simulations of common-envelope evolution and formation of planetary nebulae.

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Section: Numerical Approach For the Primary Starmentioning

confidence: 99%

AGB winds in interacting binary stars

Bermúdez-Bustamante

Garcı́a-Segura

Steffen

et al. 2020

Monthly Notices of the Royal Astronomical Society

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“…A relatively short stage in a star's life, the Mira phase is characterized by large bolometric luminosities (ranging from several hundred to tens of thousands of the solar luminosity; Iwanek et al 2021b) and low average densities (about 7-8 orders of magnitude lower than the solar density; Berlioz-Arthaud 2003;Catelan & Smith 2015). High-amplitude pulsations cause mass-loss phenomena via the stellar wind (Perrin et al 2020), which leads to the enrichment of the interstellar medium with elements heavier than nickel produced by the slow neutron-capture process.…”

Section: Introductionmentioning

confidence: 99%

The OGLE Collection of Variable Stars: Nearly 66,000 Mira Stars in the Milky Way

Iwanek

Soszyński

Kozłowski

et al. 2022

ApJS

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We present a collection of 65,981 Mira-type variable stars found in the Optical Gravitational Lensing Experiment (OGLE) project database. Two-thirds of our sample (40,356 objects) are located in the Galactic bulge fields, whereas 25,625 stars are in the Galactic disk. The vast majority of the collection (47,532 objects) comprises new discoveries. We provide basic observational parameters of the Mira variables: equatorial coordinates, pulsation periods, I-band and V-band mean magnitudes, I-band brightness amplitudes, and identifications in other catalogs of variable stars. We also provide the I-band and V-band time-series photometry collected since 1997 during the OGLE-II, OGLE-III, and OGLE-IV phases. The classical selection process, i.e., being mostly based on the visual inspection of light curves by experienced astronomers, has led to the high purity of the catalog. As a result, this collection can be used as a training set for machine-learning classification algorithms. Using overlapping areas of adjacent OGLE fields, we estimate the completeness of the catalog to be about 96%. We compare and discuss the statistical features of Miras located in different regions of the Milky Way. We show examples of stars that change their type over time, from a semiregular variable to Mira and vice versa. This data set is perfectly suited to studying the three-dimensional structure of the Milky Way, and it may help to explain the puzzle of the X-shaped bulge.

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“…These undoubtedly exist and are gen-erally blamed on pulsation driven by the same opacity mechanism that applies to Cepheids. Berlioz-Arthaud (2003) would, however, like them to be engulfed planets in the giant atmospheres. The period would be about right, since anything dominated by gravity (breakup rotation, orbit, or pulsation) happens on the free-fall or dynamical timescale.…”

Section: Searches and Signaturesmentioning

confidence: 99%

Astrophysics in 2003

Trimble

Aschwanden

2004

PUBL ASTRON SOC PAC

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Five coherent sections appear this year, addressing solar physics, cosmology (with WMAP highlights), gamma-ray bursters (and their association with Type Ia supernovae), extra-solar-system planets, and the formation and evolution of galaxies (from reionization to assemblage of Local Group galaxies). There are also eight incoherent sections that deal with other topics in stellar, galactic, and planetary astronomy and the people who study them. INTRODUCTIONSTriskaidekaphobics may prefer not to read this installment of ApXX, and their numbers may well be augmented even before the introduction is over. This is, in fact, the 13th overview of 365.24 days of the astronomy and astrophysics literature. The earlier ones are cited here as Ap91, Ap92, …, Ap02 and appear in volumes 104-115 of PASP. The authors have tried to read systematically the contents of about 30 journals and other periodicals. Only about 10% of what has been read gets cited, and being cited is not always an unqualified compliment.Section 2 was assembled using papers found on the Astrophysics Data Service, maintained with support from NASA and including Solar

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Mira Variables explained by a planetary companion interaction: A means to drop the pulsation paradigm?

Cited by 5 publications

References 44 publications

AGB winds in interacting binary stars

AGB winds in interacting binary stars

The OGLE Collection of Variable Stars: Nearly 66,000 Mira Stars in the Milky Way

Astrophysics in 2003

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