Photometric detection of non-transiting short-period low-mass companions through the beaming, ellipsoidal and reflection effects in Kepler and CoRoT light curves

AbstractGood-quality empirical results on 62 short-period binary stars recently summarised by Hilditch & Bell (1987) and Hilditch, King & McFarlane (1988) are discussed in terms of evolutionary paths from detached to semi-detached and contact states. These data suggest two evolutionary paths to the contact binaries - from detached systems directly into contact to form initially shallow-contact systems, and via case A mass transfer to semi-detached states, thence to contact systems. These empirical results support previous arguments based on evolutionary models and less detailed observational data.Concern is expressed about the paucity of high-quality spectroscopic data, particularly for low-mass systems displaying EB-type light curves and the resultant limitations on analyses of those light curves. Such systems provide tests of evolution into contact for the first time, or of broken-contact phases for WUMa-type binaries. The crucial importance of long-term monitoring (decades) of times of minima as indicators of mass transfer rates amongst these interacting binaries is also noted.

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IM Normae: The Death Spiral of a Cataclysmic Variable?

The Astrophysical Journal ◽

10.3847/1538-4357/abec87 ◽

2022 ◽

Vol 924 (1) ◽

pp. 27

Author(s):

Joseph Patterson ◽

Jonathan Kemp ◽

Berto Monard ◽

Gordon Myers ◽

Enrique de Miguel ◽

...

Keyword(s):

Mass Transfer ◽

Light Curves ◽

High Rate ◽

High Mass ◽

Cataclysmic Variable ◽

Short Period ◽

Accretion Rates ◽

Low Mass ◽

Recurrent Nova ◽

Cataclysmic Variable Evolution

Abstract We present a study of the orbital light curves of the recurrent nova IM Normae since its 2002 outburst. The broad “eclipses” recur with a 2.46 hr period, which increases on a timescale of 1.28(16) × 106 yr. Under the assumption of conservative mass transfer, this suggests a rate near 10−7 M ⊙ yr−1, and this agrees with the estimated accretion rate of the postnova, based on our estimate of luminosity. IM Nor appears to be a close match to the famous recurrent nova T Pyxidis. Both stars appear to have very high accretion rates, sufficient to drive the recurrent-nova events. Both have quiescent light curves, which suggest strong heating of the low-mass secondary, and very wide orbital minima, which suggest obscuration of a large “corona” around the primary. And both have very rapid orbital period increases, as expected from a short-period binary with high mass transfer from the low-mass component. These two stars may represent a final stage of nova—and cataclysmic variable—evolution, in which irradiation-driven winds drive a high rate of mass transfer, thereby evaporating the donor star in a paroxysm of nova outbursts.

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Rapidly Evolving Light Curves of Low Mass X-Ray Binaries

International Astronomical Union Colloquium ◽

10.1017/s0252921100152571 ◽

2004 ◽

Vol 194 ◽

pp. 211-211

Author(s):

P. Muhli ◽

P. J. Hakala ◽

L. Hjalmarsdotter ◽

D. C. Hannikainen ◽

J. Schultz

Keyword(s):

Neutron Star ◽

Light Curve ◽

Light Curves ◽

Type I ◽

X Ray ◽

Short Period ◽

First Results ◽

Low Mass ◽

Photometric Monitoring ◽

X Ray Binaries

A few Galactic Low Mass X-Ray Binaries (LMXBs) have shown drastically evolving X-ray and/or optical orbital light curves. In two short-period LMXBs, MS 1603+2600 (= UW CrB, Porb = 111 min) and 4U 1916-053 (see e.g. Homer et al. 2001), the variations in the light curve morphology seem to be repeating in a periodic manner. We present first results of a photometric monitoring campaign of MS 1603+2600, showing evidence of a 5-day superorbital period in this yet unclassified source. The observations also unraveled optical flares, reminiscent of type I bursts, suggesting a neutron star primary.

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Quasi-Periodic Oscillations in Dwarf Novae

International Astronomical Union Colloquium ◽

10.1017/s0252921100073310 ◽

1979 ◽

Vol 46 ◽

pp. 77-88

Author(s):

Edward L. Robinson

Keyword(s):

Binary Systems ◽

Outer Edge ◽

Light Curves ◽

Close Binary ◽

Bright Spot ◽

Dwarf Novae ◽

Periodic Oscillations ◽

High Frequencies ◽

Short Period ◽

Typical Time

Three distinct kinds of rapid variations have been detected in the light curves of dwarf novae: rapid flickering, short period coherent oscillations, and quasi-periodic oscillations. The rapid flickering is seen in the light curves of most, if not all, dwarf novae, and is especially apparent during minimum light between eruptions. The flickering has a typical time scale of a few minutes or less and a typical amplitude of about .1 mag. The flickering is completely random and unpredictable; the power spectrum of flickering shows only a slow decrease from low to high frequencies. The observations of U Gem by Warner and Nather (1971) showed conclusively that most of the flickering is produced by variations in the luminosity of the bright spot near the outer edge of the accretion disk around the white dwarf in these close binary systems.

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SuperWASP variable stars: classifying light curves using citizen science

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab140 ◽

2021 ◽

Vol 502 (1) ◽

pp. 1299-1311

Author(s):

Heidi B Thiemann ◽

Andrew J Norton ◽

Hugh J Dickinson ◽

Adam McMaster ◽

Ulrich C Kolb

Keyword(s):

Variable Stars ◽

Eclipsing Binaries ◽

Light Curves ◽

Data Set ◽

Resultant Data ◽

Sky Survey ◽

Short Period ◽

Contact Binaries ◽

Analysis Of Results

ABSTRACT We present the first analysis of results from the SuperWASP variable stars Zooniverse project, which is aiming to classify 1.6 million phase-folded light curves of candidate stellar variables observed by the SuperWASP all sky survey with periods detected in the SuperWASP periodicity catalogue. The resultant data set currently contains >1 million classifications corresponding to >500 000 object–period combinations, provided by citizen–scientist volunteers. Volunteer-classified light curves have ∼89 per cent accuracy for detached and semidetached eclipsing binaries, but only ∼9 per cent accuracy for rotationally modulated variables, based on known objects. We demonstrate that this Zooniverse project will be valuable for both population studies of individual variable types and the identification of stellar variables for follow-up. We present preliminary findings on various unique and extreme variables in this analysis, including long-period contact binaries and binaries near the short-period cut-off, and we identify 301 previously unknown binaries and pulsators. We are now in the process of developing a web portal to enable other researchers to access the outputs of the SuperWASP variable stars project.

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The study of multipeaked type-I X-ray bursts in the neutron star low-mass X-ray binary 4U 1636 − 536 with RXTE

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3539 ◽

2020 ◽

Vol 501 (1) ◽

pp. 168-178

Author(s):

Chen Li ◽

Guobao Zhang ◽

Mariano Méndez ◽

Jiancheng Wang ◽

Ming Lyu

Keyword(s):

Neutron Star ◽

Flux Ratio ◽

Light Curves ◽

Type I ◽

X Ray ◽

Soft State ◽

Peak Flux ◽

Low Mass ◽

Two Peaks ◽

Second Peak

ABSTRACT We have found and analysed 16 multipeaked type-I bursts from the neutron-star low-mass X-ray binary 4U 1636 − 53 with the Rossi X-ray Timing Explorer (RXTE). One of the bursts is a rare quadruple-peaked burst that was not previously reported. All 16 bursts show a multipeaked structure not only in the X-ray light curves but also in the bolometric light curves. Most of the multipeaked bursts appear in observations during the transition from the hard to the soft state in the colour–colour diagram. We find an anticorrelation between the second peak flux and the separation time between two peaks. We also find that in the double-peaked bursts the peak-flux ratio and the temperature of the thermal component in the pre-burst spectra are correlated. This indicates that the double-peaked structure in the light curve of the bursts may be affected by enhanced accretion rate in the disc, or increased temperature of the neutron star.

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V392 Orionis: Observations and Evolutionary State of a Low-Mass System

Highlights of Astronomy ◽

10.1017/s1539299600021213 ◽

1998 ◽

Vol 11 (1) ◽

pp. 371-371

Author(s):

S. Narusawa ◽

A. Yamasaki ◽

Y. Nakamura

Keyword(s):

Binary Systems ◽

Main Sequence ◽

Circumstellar Matter ◽

Small Mass ◽

Primary Component ◽

Close Binary ◽

Mass System ◽

Future Evolution ◽

Short Period ◽

Low Mass

Although the evolution of binary systems has been qualitatively interpreted with the evolutionary scenario, the quantitative interpretation of any observed system is still unsatisfactory due to the difficulty of the quantitative treatment of mass and angular momentum transfer/loss. To reach a true understanding of the evolution of binary systems, we have to accumulate more observational evidence. So far, we have observed several binaries that are short-period and noncontact, and found the existence of extremely small-mass systems. In the present paper, we study another short-period (P=0.659d), noncontact, eclipsing binary system, V392 Ori. We have made photometric and spectroscopic observations of V392 Ori. The light curves are found to vary, suggesting the existence of circumstellar matter around the system. Combining the photometric and spectroscopic results, we obtain parameters describing the system; we find the mass of the primary component is only 0.6Mʘ- undermassive for its spectral and luminosity class A5V, suggesting that a considerable amount of its original mass has been lost from the system during the course of evolution. The low-mass problem is very important for investigation of the evolution of close binary systems: largemass loss within and/or after the main-sequence will have a significant influence on the future evolution of binary systems.

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The diverse origin of exoplanets' eccentricities & inclinations

Proceedings of the International Astronomical Union ◽

10.1017/s1743921311020217 ◽

2010 ◽

Vol 6 (S276) ◽

pp. 221-224

Author(s):

Eric B. Ford

Keyword(s):

Rotation Axis ◽

Orbital Evolution ◽

Giant Planets ◽

Direct Imaging ◽

Wide Binary ◽

Hot Jupiters ◽

Short Period ◽

New Type ◽

Low Mass ◽

Diverse Origin

AbstractRadial velocity surveys have discovered over 400 exoplanets. While measuring eccentricities of low-mass planets remains a challenge, giant exoplanets display a broad range of orbital eccentricities. Recently, spectroscopic measurements during transit have demonstrated that the short-period giant planets (“hot-Jupiters”) also display a broad range of orbital inclinations (relative to the rotation axis of the host star). Both properties pose a challenge for simple disk migration models and suggest that late-stage orbital evolution can play an important role in determining the final architecture of planetary systems. One possible formation mechanism for the inclined hot-Jupiters is some form of eccentricity excitation (e.g., planet scattering, secular perturbations due to a distant planet or wide binary) followed tidal circularization. The planet scattering hypothesis also makes predictions for the population of planets at large separations. Recent discoveries of planets on wide orbits via direct imaging and highly anticipated results from upcoming direct imaging campaigns are poised to provide a new type of constraint on planet formation. This proceedings describes recent progress in understanding the formation of giant exoplanets.

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The Census of Exoplanets in Visual Binaries: Population Trends from a Volume-Limited Gaia DR2 and Literature Search

Frontiers in Astronomy and Space Sciences ◽

10.3389/fspas.2021.625250 ◽

2021 ◽

Vol 8 ◽

Author(s):

Clémence Fontanive ◽

Daniella Bardalez Gagliuffi

Keyword(s):

Planetary Systems ◽

Multiple Star ◽

Multiple Systems ◽

Binary Separation ◽

Extensive Search ◽

Short Period ◽

Massive Component ◽

Low Mass ◽

Cool Gas ◽

Gaia Dr2

We present results from an extensive search in the literature and Gaia DR2 for visual co-moving binary companions to stars hosting exoplanets and brown dwarfs within 200 pc. We found 218 planet hosts out of the 938 in our sample to be part of multiple-star systems, with 10 newly discovered binaries and 2 new tertiary stellar components. This represents an overall raw multiplicity rate of 23.2 ± 1.6 % for hosts to exoplanets across all spectral types, with multi-planet systems found to have a lower stellar duplicity frequency at the 2.2-σ level. We found that more massive hosts are more often in binary configurations, and that planet-bearing stars in multiple systems are predominantly observed to be the most massive component of stellar binaries. Investigations of the multiplicity of planetary systems as a function of planet mass and separation revealed that giant planets with masses above 0.1 MJup are more frequently seen in stellar binaries than small sub-Jovian planets with a 3.6-σ difference, a trend enhanced for the most massive (>7 MJup) short-period (<0.5 AU) planets and brown dwarf companions. Binarity was however found to have no significant effect on the demographics of low- mass planets (<0.1 MJup) or warm and cool gas giants (>0.5 AU). While stellar companion mass appears to have no impact on planet properties, binary separation seems to be an important factor in the resulting structure of planetary systems. Stellar companions on separations <1000 AU can play a role in the formation or evolution of massive, close-in planets, while planets in wider binaries show similar properties to planets orbiting single stars. Finally, our analyses indicate that numerous stellar companions on separations smaller than 1–3 arcsec likely remain undiscovered to this date. Continuous efforts to complete our knowledge of stellar multiplicity on separations of tens to hundreds of AU are essential to confirm the reported trends and further our understanding of the roles played by multiplicity on exoplanets.

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Characterization of rocky exoplanets from their infrared phase curve

Proceedings of the International Astronomical Union ◽

10.1017/s1743921311020904 ◽

2010 ◽

Vol 6 (S276) ◽

pp. 485-486

Author(s):

Anne-Sophie Maurin ◽

Franck Selsis ◽

Franck Hersant ◽

Marco Delbò

Keyword(s):

Thermal Emission ◽

Infrared Emission ◽

Phase Curve ◽

Low Mass Stars ◽

Rotation Surface ◽

Key Population ◽

Short Period ◽

Low Mass ◽

Observation Geometry

AbstractDuring the last few years, observations have yielded an abundant population of short-period planets under 15 Earth masses. Among those, hot terrestrial exoplanets represent a key population to study the survival of dense atmospheres close to their parent star. Thermal emission from exoplanets orbiting low-mass stars will be observable with the next generation of infrared telescopes, in particular the JWST. In order to constrain planetary and atmospheric properties, we have developed models to simulate the variation of the infrared emission along the path of the orbit (IR phase curve) for both airless planets and planets with dense atmospheres. Here, we focus on airless planets and present preliminary results on the influence of orbital elements, planet rotation, surface properties and observation geometry. Then, using simulated noisy phase curves, we test the retrieval of planets' properties and identify the degeneracies.

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