The Evolution of Close Binaries
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Astronomy Astrophysics
A&A 477, 193–202 (2008) Astronomy DOI: 10.1051/0004-6361:20066086 & c ESO 2007 Astrophysics Extended shells around B[e] stars Implications for B[e] star evolution A. P. Marston1 and B. McCollum2 1 ESA/ESAC, Villafranca del Castillo, 28080 Madrid, Spain e-mail: [email protected] 2 Spitzer Science Center, IPAC, Caltech, Pasadena, CA 91125, USA e-mail: [email protected] Received 21 July 2006 / Accepted 15 October 2007 ABSTRACT Aims. The position of B[e] stars in the upper left part of the Hertzsprung-Russell diagram creates a quandary. Are these stars young stars evolving onto the main sequence or old stars that are evolving off of it? Spectral characteristics suggest that B[e] stars can be placed into five subclasses and are not a homogeneous set. Such sub-classification is believed to coincide with varying origins and different evolutions. However, the evolutionary connection of B[e] stars – and notably sgB[e] – to other stars is unclear, particularly to evolved massive stars. We attempt to provide insight into the evolutionary past of B[e] stars. Methods. We performed an Hα narrow-band CCD imaging survey of B[e] stars, in the northern hemisphere. Prior to the current work, no emission-line survey of B[e] stars had yet been made, while only two B[e] stars appeared to have a shell nebula as seen in the Digital Sky Survey. Of nebulae around B[e] stars, only the ring nebula around MWC 137 has been previously observed extensively. Results. In this presentation we report the findings from our narrow-band optical imaging survey of the environments of 25 B[e] stars. -
Observations of Gamma-Ray Binaries with VERITAS
Observations of gamma-ray binaries with VERITAS PSR J1023+0038, HESS J0632+057 & LS I +61 303 Gernot Maier for the VERITAS Collaboration Alliance for Astroparticle Physics VERITAS > array of four 12 m Imaging Atmospheric Cherenkov Telescopes located in southern Arizona > energy range: 85 GeV to >30 TeV > field of view of 3.5 > angular resolution ~0.08 > point source sensitivity (5σ detection): 1% Crab in < 25 h (10% in 25 min) Gernot Maier Binary observations with VERITAS May 2015 The VERITAS Binary Program D GeV/TeV type of reference type orbital (kpc) period [d] detection observation (VERITAS) Be+neutron star? regular since 2006 ApJ 2008, 2009, LS I +61 303 1.6 26.5 ✔/✔ BH? (10-30 h/season) 2011, 2013 regular since 2006 HESS J0632+057 B0pe + ?? 1.5 315 ✘/✔ ApJ 2009, 2014 (10-30 h/season) 06.5V+neutron LS 5039 2.5 3.9 ✔/✔ (~10 h/season) - star? BH? Cygnus X-1 O9.7Iab + BH 2.2 5.6 (✘/✔) ToO (X-rays/LAT) - Cygnus X-3 Wolf Rayet + BH? 7 0.2 (✔)/✘ ToO (X-rays/LAT) ApJ 2013 ToO (triggered by 1A0535+262 Be/pulsar binary 2 111 ✘/✘ ApJ 733, 96 (2011) Swift XRT) Nova in a ToO (triggered by V407 Cygni 2.7 ✔/✘ ApJ 754, 77 (2012) symbiotic binary Fermi) Be/X-ray Binary Be-XRB - - - filler program - discover program BAT flaring hard SGRs+XRBs - - - ToO - X-ray objects Millisecond pulsar regular MSPB - - - - binaries (10-15 h/season) ToO Magnetars SGRs+AXPs - - - Proc of ICRC 2009 (GRB pipeline) Gernot Maier Binary observations with VERITAS May 2015 PSR J1023+0038: A new type of gamma-ray binary? PSR J1023+0038: 1.69 ms spin period, 4.8 hr orbital -
Luminous Blue Variables
Review Luminous Blue Variables Kerstin Weis 1* and Dominik J. Bomans 1,2,3 1 Astronomical Institute, Faculty for Physics and Astronomy, Ruhr University Bochum, 44801 Bochum, Germany 2 Department Plasmas with Complex Interactions, Ruhr University Bochum, 44801 Bochum, Germany 3 Ruhr Astroparticle and Plasma Physics (RAPP) Center, 44801 Bochum, Germany Received: 29 October 2019; Accepted: 18 February 2020; Published: 29 February 2020 Abstract: Luminous Blue Variables are massive evolved stars, here we introduce this outstanding class of objects. Described are the specific characteristics, the evolutionary state and what they are connected to other phases and types of massive stars. Our current knowledge of LBVs is limited by the fact that in comparison to other stellar classes and phases only a few “true” LBVs are known. This results from the lack of a unique, fast and always reliable identification scheme for LBVs. It literally takes time to get a true classification of a LBV. In addition the short duration of the LBV phase makes it even harder to catch and identify a star as LBV. We summarize here what is known so far, give an overview of the LBV population and the list of LBV host galaxies. LBV are clearly an important and still not fully understood phase in the live of (very) massive stars, especially due to the large and time variable mass loss during the LBV phase. We like to emphasize again the problem how to clearly identify LBV and that there are more than just one type of LBVs: The giant eruption LBVs or h Car analogs and the S Dor cycle LBVs. -
The Evolution of Luminous Red Nova at 2017Jfs in NGC 4470
The evolution of luminous red nova AT 2017jfs in NGC 4470 Pastorello, A.; Chen, T. -W.; Cai, Y. -Z.; Morales-Garoffolo, A.; Cano, Z.; Mason, E.; Barsukova, E. A.; Benetti, S.; Berton, M.; Bose, S.; Bufano, F.; Callis, E.; Cannizzaro, G.; Cartier, R.; Chen, Ping; Dong, Subo; Dyrbye, S.; Elias-Rosa, N.; Floers, A.; Fraser, M.; Geier, S.; Goranskij, V. P.; Kann, D. A.; Kuncarayakti, H.; Onori, F.; Reguitti, A.; Reynolds, T.; Losada, I. R.; Carracedo, A. Sagues; Schweyer, T.; Smartt, S. J.; Tatarnikov, A. M.; Valeev, A. F.; Vogl, C.; Wevers, T.; de Ugarte Postigo, A.; Izzo, L.; Inserra, C.; Kankare, E.; Maguire, K.; Smith, K. W.; Stalder, B.; Tartaglia, L.; Thone, C. C.; Valerin, G.; Young, D. R. Published in: Astronomy & Astrophysics DOI: 10.1051/0004-6361/201935511 Publication date: 2019 Document version Publisher's PDF, also known as Version of record Document license: CC BY-NC Citation for published version (APA): Pastorello, A., Chen, T. -W., Cai, Y. -Z., Morales-Garoffolo, A., Cano, Z., Mason, E., Barsukova, E. A., Benetti, S., Berton, M., Bose, S., Bufano, F., Callis, E., Cannizzaro, G., Cartier, R., Chen, P., Dong, S., Dyrbye, S., Elias- Rosa, N., Floers, A., ... Young, D. R. (2019). The evolution of luminous red nova AT 2017jfs in NGC 4470. Astronomy & Astrophysics, 625, [L8]. https://doi.org/10.1051/0004-6361/201935511 Download date: 24. sep.. 2021 A&A 625, L8 (2019) Astronomy https://doi.org/10.1051/0004-6361/201935511 & c ESO 2019 Astrophysics LETTER TO THE EDITOR The evolution of luminous red nova AT 2017jfs in NGC 4470? A. -
Formation of High-Field Magnetic White Dwarfs from Common Envelopes
Formation of high-field magnetic white dwarfs from common envelopes Jason Nordhausa,1, Sarah Wellonsa, David S. Spiegela, Brian D. Metzgera, and Eric G. Blackmanb aDepartment of Astrophysical Sciences, Princeton University, Princeton, NJ 08544; and bDepartment of Physics and Astronomy, University of Rochester, Rochester, NY 14627 Edited by Neta A. Bahcall, Princeton University, Princeton, NJ, and approved January 12, 2011 (received for review October 6, 2010) The origin of highly magnetized white dwarfs has remained a mys- a nondegenerate companion), and SDSS has identified 149 tery since their initial discovery. Recent observations indicate that HFMWDs (none of which has a nondegenerate companion). the formation of high-field magnetic white dwarfs is intimately Assuming binomial statistics, the maximum probability of obtain- related to strong binary interactions during post-main-sequence ing samples at least this different from the same underlying −10 phases of stellar evolution. If a low-mass companion, such as a population is 5.7 × 10 , suggesting at the 6.2-σ level that the planet, brown dwarf, or low-mass star, is engulfed by a post-main- two populations are different (for details on this kind of calcula- sequence giant, gravitational torques in the envelope of the giant tion, see Appendix B of ref. 14). Furthermore, SDSS identified lead to a reduction of the companion’s orbit. Sufficiently low-mass 1,253 WD+M-dwarf binaries (none of which are magnetic). As companions in-spiral until they are shredded by the strong gravita- was previously pointed out, this suggests that the presence or tional tides near the white dwarf core. -
Study of Eclipsing Binaries: Light Curves & O-C Diagrams Interpretation
galaxies Review Study of Eclipsing Binaries: Light Curves & O-C Diagrams Interpretation Helen Rovithis-Livaniou Department of Astrophysics, Astronomy & Mechanics, Faculty of Physics, Panepistimiopolis, Zografos, Athens University, 15784 Athens, Greece; [email protected]; Tel.: +30-21-0984-7232 Received: 10 October 2020; Accepted: 6 November 2020; Published: 13 November 2020 Abstract: The continuous improvement in observational methods of eclipsing binaries, EBs, yield more accurate data, while the development of their light curves, that is magnitude versus time, analysis yield more precise results. Even so, and in spite the large number of EBs and the huge amount of observational data obtained mainly by space missions, the ways of getting the appropriate information for their physical parameters etc. is either from their light curves and/or from their period variations via the study of their (O-C) diagrams. The latter express the differences between the observed, O, and the calculated, C, times of minimum light. Thus, old and new light curves analysis methods of EBs to obtain their principal parameters will be considered, with examples mainly from our own observational material, and their subsequent light curves analysis using either old or new methods. Similarly, the orbital period changes of EBs via their (O-C) diagrams are referred to with emphasis on the use of continuous methods for their treatment in absence of sudden or abrupt events. Finally, a general discussion is given concerning these two topics as well as to a few related subjects. Keywords: eclipsing binaries; light curves analysis/synthesis; minima times and (O-C) diagrams 1. Introduction A lot of time has passed since the primitive observations of EBs made with naked eye till today’s space surveys. -
Gaia Data Release 2 Special Issue
A&A 623, A110 (2019) Astronomy https://doi.org/10.1051/0004-6361/201833304 & © ESO 2019 Astrophysics Gaia Data Release 2 Special issue Gaia Data Release 2 Variable stars in the colour-absolute magnitude diagram?,?? Gaia Collaboration, L. Eyer1, L. Rimoldini2, M. Audard1, R. I. Anderson3,1, K. Nienartowicz2, F. Glass1, O. Marchal4, M. Grenon1, N. Mowlavi1, B. Holl1, G. Clementini5, C. Aerts6,7, T. Mazeh8, D. W. Evans9, L. Szabados10, A. G. A. Brown11, A. Vallenari12, T. Prusti13, J. H. J. de Bruijne13, C. Babusiaux4,14, C. A. L. Bailer-Jones15, M. Biermann16, F. Jansen17, C. Jordi18, S. A. Klioner19, U. Lammers20, L. Lindegren21, X. Luri18, F. Mignard22, C. Panem23, D. Pourbaix24,25, S. Randich26, P. Sartoretti4, H. I. Siddiqui27, C. Soubiran28, F. van Leeuwen9, N. A. Walton9, F. Arenou4, U. Bastian16, M. Cropper29, R. Drimmel30, D. Katz4, M. G. Lattanzi30, J. Bakker20, C. Cacciari5, J. Castañeda18, L. Chaoul23, N. Cheek31, F. De Angeli9, C. Fabricius18, R. Guerra20, E. Masana18, R. Messineo32, P. Panuzzo4, J. Portell18, M. Riello9, G. M. Seabroke29, P. Tanga22, F. Thévenin22, G. Gracia-Abril33,16, G. Comoretto27, M. Garcia-Reinaldos20, D. Teyssier27, M. Altmann16,34, R. Andrae15, I. Bellas-Velidis35, K. Benson29, J. Berthier36, R. Blomme37, P. Burgess9, G. Busso9, B. Carry22,36, A. Cellino30, M. Clotet18, O. Creevey22, M. Davidson38, J. De Ridder6, L. Delchambre39, A. Dell’Oro26, C. Ducourant28, J. Fernández-Hernández40, M. Fouesneau15, Y. Frémat37, L. Galluccio22, M. García-Torres41, J. González-Núñez31,42, J. J. González-Vidal18, E. Gosset39,25, L. P. Guy2,43, J.-L. Halbwachs44, N. C. Hambly38, D. -
Orihin and Evolution of Magnetars
Origin and evolution of magnetars Sergei Popov (SAI MSU) (co-authors: A. Bogomazov, M. Prokhorov, R. Turolla) Plan of the talk • Origin of magnetars. Role of binaries • Evolution of magnetars. Binaries as probes. • Frozen magnetars in CCOs Origin of magnetars field Generated Fossil Critisized by Spruit (2008) Classical dynamo scenario starting from DT in 90s Dynamo mechanism conditions Rapid rotation is necessary! P0~ few msec This is difficult to achieve due to slowdown of a stellar core rotation (Heger et al. 2004, Meynet, Maeder 2005). The same problem appear in GRB scenario. Stellar rotation can be enhanced only in binaries. There are different possibilities to gain additional angular momentum due to mass transfer or tidal interaction. We need to to perform population synthesis calculations. Binary evolution channels. I. Among all possible evolutionary paths that result in formation of NSs we select those that lead to angular momentum increase of progenitors. • Coalescence prior to a NS formation. • Roche lobe overflow by a primary without a common envelope. • Roche lobe overflow by a primary with a common envelope. • Roche lobe overflow by a secondary without a common envelope. • Roche lobe overflow by a secondary with a common envelope. This is an optimistic scenarion, as it is assumed that angular momentum is not lost in significant amount after it has been gained (astro-ph/0505406) Products of binaries. I. In the “optimistic” scenario we obtain that rapidly rotating cores are mainly produced by mergers and by first RLO (i.e. the secondary companion gets angluar momentum). Mostly, compact objects formed via these channels are isolated. -
Stellar Evolution
AccessScience from McGraw-Hill Education Page 1 of 19 www.accessscience.com Stellar evolution Contributed by: James B. Kaler Publication year: 2014 The large-scale, systematic, and irreversible changes over time of the structure and composition of a star. Types of stars Dozens of different types of stars populate the Milky Way Galaxy. The most common are main-sequence dwarfs like the Sun that fuse hydrogen into helium within their cores (the core of the Sun occupies about half its mass). Dwarfs run the full gamut of stellar masses, from perhaps as much as 200 solar masses (200 M,⊙) down to the minimum of 0.075 solar mass (beneath which the full proton-proton chain does not operate). They occupy the spectral sequence from class O (maximum effective temperature nearly 50,000 K or 90,000◦F, maximum luminosity 5 × 10,6 solar), through classes B, A, F, G, K, and M, to the new class L (2400 K or 3860◦F and under, typical luminosity below 10,−4 solar). Within the main sequence, they break into two broad groups, those under 1.3 solar masses (class F5), whose luminosities derive from the proton-proton chain, and higher-mass stars that are supported principally by the carbon cycle. Below the end of the main sequence (masses less than 0.075 M,⊙) lie the brown dwarfs that occupy half of class L and all of class T (the latter under 1400 K or 2060◦F). These shine both from gravitational energy and from fusion of their natural deuterium. Their low-mass limit is unknown. -
Mass of the White Dwarf in the Symbiotic Binary Star MWC 560
Mass of the white dwarf in the symbiotic binary star MWC 560 Radoslev Zamanov1, Andreja Gomboc2, Georgi Latev1 1 Institute of Astronomy and NAO, Bulgarian Academy of Sciences, BG-1784 Sofia 2 Faculty of Mathematics and Physics, University of Ljubljana, SI-1000 Ljubljana [email protected]; [email protected] (Research report. Accepted on 23.06.2011) Abstract. We report an estimate of the white dwarf parameters in the symbiotic binary star MWC 560. We calculate white dwarf mass to be MWD = 0.85 − 1.0 M⊙ and its radius to be RWD = 6900 − 5600 km. Our estimate is derived on the basis of the observed ejection velocities and suggested connection between jet and escape velocities. Key words: stars: binaries: close – binaries: symbiotic – stars: individual (MWC 560) Маса на бялото джудже в симбиотичната двойна звезда MWC 560 Радослав Заманов, Андрея Гомбоц, Георги Латев Ние докладваме една оценка на параметрите на бялото джудже в симбиотичната двойна звезда MWC 560. Изчислихме, че неговата маса е MWD = 085 − 1.0 M⊙ и радиусът му е RWD = 6900−5600 км. Оценката е направена на база на наблюдаваните скорости на изхвърляне на вещество и връзка между скоростта на джета и скоростта на освобождаване (втора космическа). 1 Introduction MWC 560 (V694 Monocerotis) was discovered as an object with bright hy- drogen lines (Merrill & Burwell 1943). It is a symbiotic binary system, which consists of a red giant and a white dwarf. The orbital period is estimated to be Porb = 1931 162 day (Gromadzki et al. 2007). Its optical spectrum shows prominent emission± lines of H I, He I, Fe II, Ti II superimposed on the absorption features of an M type giant (Chentsov et al. -
The Symbiotic Stars 79
6 The Symbiotic Stars ULISSE MUNARI 6.1 Symbiotic Stars: Binaries accreting from a Red Giant When Merrill and Humason (1932) discovered CI Cyg and AX Per, the first known sym- biotic stars (hereafter SySts), they were puzzled (in line with the wisdom of the time, not easily contemplating stellar binarity) by the co-existence in the ’same’ star of features be- longing to distant cornersof the HR diagram: the TiO bands typical of the coolest M giants, the HeII 4686 A˚ seen only in the hottest O-type stars, and an emission line spectrum match- ing that of planetary nebulae (hereafter PN). All these features stands out prominently in the spectrum of CI Cyg shown in Figure 6.1 together with its light-curve displaying a large assortment of different types of variability, with the spectral appearance changing in pace (a brighter state usually comes with bluer colors and a lower ionization). A great incentive to the study of SySts was provided in the 1980ies by the first confer- ence (Friedjung and Viotti, 1982) and monograph(Kenyon, 1986) devoted entirely to them, the first catalog and spectral atlas of known SySts by Allen (1984), and the first simple ge- ometrical modeling of their ionization front (Seaquist et al., 1984). Allen offered a clean classification criterium for SySts: a binary star, combining a red giant (RG) and a compan- ion hot enough to sustain HeII (or higher ionization) emission lines. The spectral atlas by Munari and Zwitter (2002), shows how the majorityof SySts meeting this criterium display in their spectra emission lines of at least the NeV, OVI or FeVII ionization stages, requiring a minimum photo-ionization temperature of 130,000 K (Murset and Nussbaumer, 1994). -
Variable Star
Variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) fluctuates. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as either: Intrinsic variables, whose luminosity actually changes; for example, because the star periodically swells and shrinks. Extrinsic variables, whose apparent changes in brightness are due to changes in the amount of their light that can reach Earth; for example, because the star has an orbiting companion that sometimes Trifid Nebula contains Cepheid variable stars eclipses it. Many, possibly most, stars have at least some variation in luminosity: the energy output of our Sun, for example, varies by about 0.1% over an 11-year solar cycle.[1] Contents Discovery Detecting variability Variable star observations Interpretation of observations Nomenclature Classification Intrinsic variable stars Pulsating variable stars Eruptive variable stars Cataclysmic or explosive variable stars Extrinsic variable stars Rotating variable stars Eclipsing binaries Planetary transits See also References External links Discovery An ancient Egyptian calendar of lucky and unlucky days composed some 3,200 years ago may be the oldest preserved historical document of the discovery of a variable star, the eclipsing binary Algol.[2][3][4] Of the modern astronomers, the first variable star was identified in 1638 when Johannes Holwarda noticed that Omicron Ceti (later named Mira) pulsated in a cycle taking 11 months; the star had previously been described as a nova by David Fabricius in 1596. This discovery, combined with supernovae observed in 1572 and 1604, proved that the starry sky was not eternally invariable as Aristotle and other ancient philosophers had taught.