Ongoing surveys for close binary central stars and wider implications

AbstractBinary central stars have long been invoked to explain the vexing shapes of planetary nebulae (PNe) despite there being scant direct evidence to support this hypothesis. Modern large-scale surveys and improved observing strategies have allowed us to significantly boost the number of known close binary central stars and estimate at least 20% of PNe have close binary nuclei that passed through a common-envelope (CE) phase. The larger sample of post-CE nebulae appears to have a high proportion of bipolar nebulae, low-ionisation structures (especially in SN1987A-like rings) and polar outflows or jets. These trends are guiding our target selection in ongoing multi-epoch spectroscopic and photometric surveys for new binaries. Multiple new discoveries are being uncovered that further strengthen the connection between post-CE trends and close binaries. These ongoing surveys also have wider implications for understanding CE evolution, low-ionisation structure and jet formation, spectral classification of central stars, asymptotic giant branch (AGB) nucleosynthesis and dust obscuration events in PNe.

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The first water fountain in a planetary nebula

Proceedings of the International Astronomical Union ◽

10.1017/s1743921312007016 ◽

2012 ◽

Vol 8 (S287) ◽

pp. 230-234

Author(s):

Olga Suárez ◽

José Francisco Gómez ◽

Philippe Bendjoya ◽

Luis. F. Miranda ◽

Martín. A. Guerrero ◽

...

Keyword(s):

Mass Loss ◽

Planetary Nebula ◽

Asymptotic Giant Branch ◽

Survival Times ◽

Jet Formation ◽

Evolved Stars ◽

Water Masers ◽

First Time ◽

Water Maser

AbstractWater fountains are evolved stars showing water masers with velocity spanning more than ~100 km/s. They usually appear at the end of the Asymptotic Giant Branch (AGB) phase or at the beginning of the post-AGB phase, and their masers trace the first manifestation of axisymmetric collimated mass-loss. For the first time, masers with water fountain characteristics have been detected towards a PN (IRAS 15103–5754), which might require a revision of the current theories about jet formation and survival times. IRAS 15103-5754 was observed using the ATCA interferometer at 22 GHz (both continuum and water maser). The main results of these observations are summarized here. The evolutionary classification of this object is also discussed.

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The Binaries from Unstable Triples. Dynamical Processes of Formation

Highlights of Astronomy ◽

10.1017/s1539299600007644 ◽

1989 ◽

Vol 8 ◽

pp. 143-144

Author(s):

Joanna P. Anosova

Keyword(s):

Computer Simulations ◽

Dynamical Evolution ◽

Close Binary ◽

Close Binaries ◽

State University ◽

Dynamical Processes ◽

Triple Systems ◽

Gravitational Problem ◽

Three Body

The dynamical processes of formation, evolution and disruption of binaries may be effectively studied by computer simulations in the N > 3-body gravitational problem. As a result of analysis of these investigations of diverse authors, the classification of the dynamical processes of formation of wide and close binaries may be proposed (see Table 1). This Table shows the following general processes: I-triple approaches of the single bodies; II-approaches of binaries with single bodies; Ill-escape from physical triples. The actions of these processes, and kinetics of a frequency of binaries in general field were studied at the Astronomical Observatory of the Leningrad State University (1965-1988) by computer simulations in the three-body problem. More than 3.104 orbits with negative total energy E < 0 and 5.104 with E > 0 have been run on the computers. The film “Dynamical evolution of triple systems” was produced. Part I of this movie shows the evolution of the unstable non-hierarchical triplet as well as the processes of formation, evolution, and disruption of temporary wide and final close binaries inside the physical triples. Part II of film presents in detail the trajectories of the bodies on the triple approaches of “fly-by”-and of “exchange”-types. The triple approach of “fly-by”-type results often in an escape from triple as well as the formation of final close binary. The triple approach of “exchange”-type consists as a rule of a few close double approaches of bodies and rarely results in an escape from triplet, it results in formation of temporary wide binary inside triplet. Part III of movie presents the trajectories of the different-mass bodies: an escape of the minimum-mass body, the intermediate-mass body, and the maximum-mass body as well as a formation of binaries with different-mass components.

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Towards a more complete sample of binary central stars of planetary nebulae with Gaia

Astronomy and Astrophysics ◽

10.1051/0004-6361/202140288 ◽

2021 ◽

Vol 648 ◽

pp. A95

Author(s):

N. Chornay ◽

N. A. Walton ◽

D. Jones ◽

H. M. J. Boffin ◽

M. Rejkuba ◽

...

Keyword(s):

Binary Systems ◽

Large Fraction ◽

Planetary Nebulae ◽

Close Binary ◽

Close Binaries ◽

Photometric Variability ◽

Long Time ◽

Using Data ◽

Central Stars

Context. Many if not most planetary nebulae (PNe) are now thought to be the outcome of binary evolutionary scenarios. However, only a few percent of the PNe in the Milky Way are known to host binary systems. The high-precision repeated observing and long time baseline of Gaia make it well suited for detecting new close binaries through photometric variability. Aims. We aim to find new close binary central stars of PNe (CSPNe) using data from the Gaia mission, building towards a statistically significant sample of post-common envelope, close binary CSPNe. Methods. As the vast majority of Gaia sources do not have published epoch photometry, we used the uncertainty in the mean photometry as a proxy for determining the variability of our CSPN sample in the second Gaia data release. We derived a quantity that expresses the significance of the variability, and considered what is necessary to build a clean sample of genuine variable sources. Results. Our selection recovers a large fraction of the known close binary CSPN population, while other CSPNe lying in the same region of the parameter space represent a promising set of targets for ground-based confirmatory follow-up observations. Gaia epoch photometry for four of the newly identified variable sources confirms that the variability is genuine and consistent with binarity.

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Binary Stars and Planetary Nebulae

Symposium - International Astronomical Union ◽

10.1017/s0074180900139075 ◽

1989 ◽

Vol 131 ◽

pp. 505-522 ◽

Cited By ~ 6

Author(s):

Icko Iben ◽

Alexander V. Tutukov

Keyword(s):

Neutron Star ◽

Binary Star ◽

Planetary Nebulae ◽

Roche Lobe ◽

Asymptotic Giant Branch ◽

Close Binaries ◽

Helium Burning ◽

Hydrogen Burning ◽

Common Envelope ◽

Central Stars

A non-negligible (∼ 15–20%) fraction of planetary nebulae is expected to be formed in close binaries in which one component fills its Roche lobe after the exhaustion of hydrogen or helium at its center. The nebula is ejected as a consequence of a frictional interaction between the stellar cores and a common envelope; the ionizing component of the central binary star may be a relatively high luminosity contracting star with a degenerate CO core, burning hydrogen or helium in a shell, or it may be a lower luminosity shell hydrogen-burning star with a degenerate helium core or a core helium-burning star. Even more exotic ionizing central stars are possible. Once the initial primary has become a white dwarf or neutron star, the secondary, after exhausting central hydrogen, will also fill its Roche lobe and eject a nebular shell in a common envelope event. The secondary becomes the ionizing star in a tight orbit with its compact companion. In all, there are roughly twenty different possibilities for the make-up of binary central stars, with the ionizing component being a post asymptotic giant branch star with a hydrogen- or helium-burning shell, a CO dwarf, a core helium-burning star, a shell helium-burning star with a degenerate CO core, a shell hydrogen-burning star with a degenerate helium core, or a helium degenerate dwarf, while its companion is a main sequence star, a CO degenerate dwarf, a helium star, a helium degenerate dwarf, or a neutron star. We estimate the occurrence frequency of several of these types and comment on the prior evolutionary history of 4 observed binary central stars.

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Close-Binary and Pulsating Central Stars

Symposium - International Astronomical Union ◽

10.1017/s0074180900138446 ◽

1989 ◽

Vol 131 ◽

pp. 251-260

Author(s):

Howard E. Bond

Keyword(s):

Binary Star ◽

Cataclysmic Variables ◽

Close Binary ◽

Close Binaries ◽

Order Of Magnitude ◽

Orbital Periods ◽

Red Giant ◽

Photometric Monitoring ◽

Significant Production ◽

Central Stars

As a result of photometric-monitoring studies, 7 planetary-nebula nuclei are now known to be binaries with orbital periods less than one day. These systems were probably produced via a common-envelope interaction, during which a wide pair was converted to a close binary surrounded by an ejected red-giant envelope. The frequency of occurrence of such close binaries among PNNs is about 10–15%, showing that binary-star interactions are a significant production mechanism for planetary nebulae. The descendants of close-binary PNNs are probably the cataclysmic variables. Two CVs surrounded by nebulae resembling old planetaries, 0623+71 and GK Per, may provide the most direct evidence for the origin of CVs through PN ejection. The observed birth rate for close-binary PNNs is more than an order of magnitude higher than for CVs, possibly indicating that our census of the CV population is very incomplete. The nucleus of K 1-16 is a member of the GW Vir class of extremely hot pulsating pre-white dwarfs, and the only one known to be surrounded by a PN. These objects offer exciting opportunities for direct measurement of evolutionary timescales and for seismological investigations of the interiors of PNNs and their immediate descendants.

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Surveying Planetary Nebulae Central Stars for Close Binaries: Constraining Evolution of Central Stars Based on Binary Parameters

Galaxies ◽

10.3390/galaxies6030085 ◽

2018 ◽

Vol 6 (3) ◽

pp. 85 ◽

Cited By ~ 2

Author(s):

Todd Hillwig

Keyword(s):

Binary Stars ◽

Planetary Nebula ◽

Planetary Nebulae ◽

Close Binary ◽

Close Binaries ◽

Common Envelope ◽

Close Binary Stars ◽

Red Giant ◽

The Relationship ◽

Central Stars

The increase in discovered close binary central stars of planetary nebulae is leading to a sufficiently large sample to begin to make broader conclusions about the effect of close binary stars on common envelope evolution and planetary nebula formation. Herein I review some of the recent results and conclusions specifically relating close binary central stars to nebular shaping, common envelope evolution off the red giant branch, and the total binary fraction and double degenerate fraction of central stars. Finally, I use parameters of known binary central stars to explore the relationship between the proto-planetary nebula and planetary nebula stages, demonstrating that the known proto-planetary nebulae are not the precursors of planetary nebulae with close binary central stars.

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The Formation of Planetary Nebulae with Close Binary Nuclei

Symposium - International Astronomical Union ◽

10.1017/s0074180900065529 ◽

1980 ◽

Vol 88 ◽

pp. 571-573

Author(s):

J. Saltzman ◽

M. Livio ◽

G. Shaviv

Keyword(s):

Planetary Nebula ◽

Planetary Nebulae ◽

Close Binary ◽

Close Binaries ◽

Central Stars

Recent observations of nuclei of planetary nebula have shown that some of the central stars are binaries and even close binaries with periods of hours to few days.

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Classification of woody-shrub vegetation of the forest-steppe complex of Privolzhskaya Upland

Vegetation of Russia ◽

10.31111/vegrus/2009.15.27 ◽

2009 ◽

pp. 27-53

Author(s):

A. Yu. Kudryavtsev

Keyword(s):

Plant Community ◽

Plant Communities ◽

Dominant Species ◽

Large Scale ◽

Nature Reserve ◽

Vegetation Mapping ◽

Vegetation Classification ◽

Forest Steppe ◽

Mapping Data

Diversity of plant communities in the nature reserve “Privolzhskaya Forest-Steppe”, Ostrovtsovsky area, is analyzed on the basis of the large-scale vegetation mapping data from 2000. The plant community classification based on the Russian ecologic-phytocoenotic approach is carried out. 12 plant formations and 21 associations are distinguished according to dominant species and a combination of ecologic-phytocoenotic groups of species. A list of vegetation classification units as well as the characteristics of theshrub and woody communities are given in this paper.

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Classification of vegetation in Cucphuong National Park with the aim of large-scale mapping, Vietnam

Geobotanical mapping ◽

10.31111/geobotmap/1994-1995.64 ◽

1996 ◽

pp. 64-67 ◽

Cited By ~ 1

Author(s):

Nguen Nghia Thin ◽

Nguen Ba Thu ◽

Tran Van Thuy

Keyword(s):

National Park ◽

Large Scale ◽

Satellite Images ◽

Field Work ◽

Aerial Photographs ◽

Vegetation Map ◽

Dense Forest ◽

Broad Leaved Forest ◽

Leaved Forest

The tropical seasonal rainy evergreen broad-leaved forest vegetation of the Cucphoung National Park has been classified and the distribution of plant communities has been shown on the map using the relations of vegetation to geology, geomorphology and pedology. The method of vegetation mapping includes: 1) the identifying of vegetation types in the remote-sensed materials (aerial photographs and satellite images); 2) field work to compile the interpretation keys and to characterize all the communities of a study area; 3) compilation of the final vegetation map using the combined information. In the classification presented a number of different level vegetation units have been identified: formation classes (3), formation sub-classes (3), formation groups (3), formations (4), subformations (10) and communities (19). Communities have been taken as mapping units. So in the vegetation map of the National Park 19 vegetation categories has been shown altogether, among them 13 are natural primary communities, and 6 are the secondary, anthropogenic ones. The secondary succession goes through 3 main stages: grassland herbaceous xerophytic vegetation, xerophytic scrub, dense forest.

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Alexandria, Kom el-Dikka. Fieldwork in the 2019 season

10.31338/uw.2083-537x.pam29.2.20 ◽

2020 ◽

pp. 469-496

Author(s):

Grzegorz Majcherek

Keyword(s):

Large Scale ◽

Direct Evidence ◽

Geometric Design ◽

Late Antique ◽

Construction Work ◽

Floor Tiles ◽

Stone Material ◽

The Mediterranean ◽

Late Roman

The report offers an account of archaeological and conservation work carried out at the site. Excavations in the central part of the site (Sector F) were continued for the fourth season in a row. Exploration of remains of early Roman houses led to the discovery of a well preserved multicolored triclinium mosaic floor with a floral and geometric design. A large assemblage of fragments of polychrome marble floor tiles, recorded in the house collapse, showed the scale of importation of decorative stone material from various regions of the Mediterranean. Overlying the early Roman strata was direct evidence of intensive construction work carried out in the vicinity in the form of large-scale kilnworks, supplying lime most probably for the building of the late Roman bath and cistern. Included in the presentation is a brief review of the limited conservation work that was conducted in the complex of late antique auditoria.

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