Article
Astronomy & Astrophysics
Alexander Kolbin, N. Borisov, N. A. Serebriakova, V. V. Shimansky, N. A. Katysheva, M. M. Gabdeev, S. Yu Shugarov
Summary: This study analyzes spectroscopic and photometric observations of the eclipsing polar BS Tri, revealing the presence of cyclotron harmonics and Zeeman components in the system. The masses, orbital inclination, and magnetic field strength of the accretion spot are refined, and the position and orientation of the magnetic dipole are estimated through modeling the light curves. The Doppler maps show the trajectory of the accretion stream and confirm the position of the accretion spot.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Kareem El-Badry, Charlie Conroy, Jim Fuller, Rocio Kiman, Jan van Roestel, Antonio C. Rodriguez, Kevin B. Burdge
Summary: We use light-curves from the ZTF to constrain the orbital period distribution of low-mass detached main-sequence eclipsing binaries. Our findings suggest that the intrinsic period distribution of these binaries is inconsistent with classical magnetic braking models, and supports the idea of a saturated magnetic field at short periods. We also find that the period distribution is not significantly affected by the convective properties of the stars in the binaries.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Ekrem Murat Esmer, Ozgur Basturk, Selim Osman Selam, Sinan Alis
Summary: This study announces the discovery of two new planetary-mass companions in the Kepler-451 binary system, which can explain the periodic variations observed. The researchers updated the orbital period and eccentricity of the middle planet and found that all three Jovian planets in the system have similar masses. The stability of the system was confirmed through a dynamical stability test.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Ekrem Murat Esmer, Ozgur Basturk, Selim Osman Selam
Summary: This study analysed the mid-eclipse timings of NY Virginis to investigate the potential circumbinary exoplanets. By modelling the available eclipse light curves and fitting a Newtonian timing model, the researchers derived orbital parameters and masses of the potential circumbinary planets. The results showed stable orbital configurations with low eccentricity, but adding a quadratic term to the model could induce eccentricity and instability.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
K. Beuermann, P. Breitenstein, E. Schwab
Summary: We present a photometric study of the newly discovered eclipsing intermediate polar J183221.56-162724.25, revealing its characteristics and parameters through photometric measurements and dynamic modeling.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
J. van Roestel, T. Kupfer, M. J. Green, T. L. S. Wong, L. Bildsten, K. Burdge, T. Prince, T. R. Marsh, P. Szkody, C. Fremling, M. J. Graham, V. S. Dhillon, S. P. Littlefair, E. C. Bellm, M. Coughlin, D. A. Duev, D. A. Goldstein, R. R. Laher, B. Rusholme, R. Riddle, R. Dekany, S. R. Kulkarni
Summary: We report the discovery of five new eclipsing AM CVn systems using the Zwicky Transient Facility (ZTF) light curves of white dwarfs selected using Gaia parallaxes. The systems were confirmed through phase-resolved spectroscopy and high-speed photometry. The presence of previously unseen spectral features in these systems provides insight into their evolutionary channels.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Xiaohui Fang, Shengbang Qian
Summary: This study investigates the evolution of systems in a hibernation scenario, identifying V1315 Aql as an example that does not enter hibernation due to unstable mass transfer. The conclusion is consistent with long-term optical observations of V1315 Aql.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
D. Pulley, I. D. Sharp, J. Mallett, S. von Harrach
Summary: Post-common envelope binary systems evolve when matter is transferred from the primary star to its secondary companion at a rate that cannot be accommodated. This results in the formation of a common envelope, which is subsequently ejected, leading to a binary system with a period between 2 and 3 hours. It is still unclear whether circumbinary companions form before or after the ejection of the common envelope. Through observations of eclipse timing variations, several systems with confirmed circumbinary planets have been identified. In this study, we analyze seven of these systems, discuss alternative causes, and evaluate the reliability of the eclipse timing variation methodology in identifying planetary companions. We conclude that the structure of these dynamic systems is not fully understood and that various factors contribute to the observed eclipse timing variations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Ingrid Pelisoli, T. R. Marsh, R. P. Ashley, Pasi Hakala, A. Aungwerojwit, K. Burdge, E. Breedt, A. J. Brown, K. Chanthorn, V. S. Dhillon, M. J. Dyer, M. J. Green, P. Kerry, S. P. Littlefair, S. G. Parsons, D. Sahman, J. F. Wild, S. Yotthanathong
Summary: Monitoring the spin history of accreting magnetic white dwarfs provides valuable insights into the interplay between spin-up and spin-down torques in binary systems. Through optical photometry and precise ephemeris derivation, this study tracked the 39-s white dwarf spin pulses in the cataclysmic variable V1460 Her, revealing a stable spin rate over a baseline of over 4 years. These results offer constraints for evolutionary models and reveal the potential for using similar techniques in other cataclysmic variable systems with rapidly rotating white dwarfs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Albert Bruch
Summary: Superhumps are variable phenomena observed in cataclysmic variables, coming in positive and negative flavors. Positive superhumps are common in short-period dwarf novae while negative superhumps are not preference for a particular type. This study utilizes TESS's long high-cadence light curves to analyze superhump behavior in old novae and novalike variables, resulting in the most comprehensive census of superhumps in these stars. Furthermore, eclipse epochs derived from the TESS light curves are used to update orbital ephemeris and discuss period changes.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Albert Bruch
Summary: This study identifies and characterizes periodic and non-periodic variations in high cadence light curves of cataclysmic variables. The results are presented for 23 nova-like variables and old novae out of a sample of 127 systems. The study explores the basic properties of superhumps and updates previous data on superhumps and the Stolz-Schoembs relation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
J. Lillo-Box, A. Ribas, B. Montesinos, N. C. Santos, T. Campante, M. Cunha, D. Barrado, E. Villaver, S. Sousa, H. Bouy, A. Aller, E. Corsaro, T. Li, J. M. J. Ong, I Rebollido, J. Audenaert, F. Pereira
Summary: This paper presents a detailed analysis of a false positive, revealing it as a hierarchical triple system composed of a giant star and a brown dwarf. The brown dwarf KOI-3886 C is one of the most irradiated brown dwarfs known to date, showing the largest radius in its substellar regime. The study highlights the importance of follow-up observations for extrasolar planets detected through transit techniques using large-pixel photometers like Kepler and TESS.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
M. Wolf, H. Kucakova, P. Zasche, K. Hornoch, J. Kara, J. Merc, M. Zejda
Summary: The study presents new observational data on three dwarf eclipsing binaries, discussing the potential existence of third bodies with short orbital periods. For SDSS J143547.87+373338.5 and NSVS 07826147, period variations can be modeled simply based on a single circumbinary object, while for NSVS 14256825, more complex behavior may be involved.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Albert Bruch
Summary: The study shows that there is no correlation between the flickering strength and simple parameters such as component masses, orbital inclination, or period, but a dependence on the absolute magnitude of the primary component and on the CV subtype was found. In different systems, the flickering strength varies with orbital phase or superhump phase in novalike variables.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
V. P. Kozhevnikov
Summary: The author conducted photometric observations of the cataclysmic variable candidate ZTF17aaaeefu, discovering very deep eclipses and brightness changes resembling dwarf nova outbursts. The precise measurement of the orbital period and derivation of the eclipse ephemeris have important implications for future studies and determination of the masses of its stellar components.
ASTROPHYSICS AND SPACE SCIENCE
(2021)
Article
Astronomy & Astrophysics
Y-L Mong, K. Ackley, T. L. Killestein, D. K. Galloway, C. Vassallo, M. Dyer, R. Cutter, M. J. Brown, J. Lyman, K. Ulaczyk, D. Steeghs, V Dhillon, P. O'Brien, G. Ramsay, K. Noysena, R. Kotak, R. Breton, L. Nuttall, E. Palle, D. Pollacco, E. Thrane, S. Awiphan, U. Burhanudin, P. Chote, A. Chrimes, E. Daw, C. Duffy, R. Eyles-Ferris, B. P. Gompertz, T. Heikkila, P. Irawati, M. Kennedy, A. Levan, S. Littlefair, L. Makrygianni, T. Marsh, D. Mata Sanchez, S. Mattila, J. R. Maund, J. McCormac, D. Mkrtichian, J. Mullaney, E. Rol, U. Sawangwit, E. Stanway, R. Starling, P. Strom, S. Tooke, K. Wiersema
Summary: Developing an effective automatic classifier to distinguish genuine sources from artifacts is crucial in wide-field optical surveys. The deep-embedded self-organizing map (DESOM), a self-supervised machine learning model, is applied to the real-bogus classification problem, utilizing clustering based on dimensionality-reduced representations. The best DESOM classifier demonstrates a 6.6% missed detection rate and a 1.5% false-positive rate, offering a nuanced approach to fine-tune decision boundaries when combined with other classifiers.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Mairi W. O'Brien, P-E Tremblay, N. P. Gentile Fusillo, M. A. Hollands, B. T. Gansicke, D. Koester, I Pelisoli, E. Cukanovaite, T. Cunningham, A. E. Doyle, A. Elms, J. Farihi, J. J. Hermes, J. Holberg, S. Jordan, B. L. Klein, S. J. Kleinman, C. J. Manser, D. De Martino, T. R. Marsh, J. McCleery, C. Melis, A. Nitta, S. G. Parsons, R. Raddi, A. Rebassa-Mansergas, M. R. Schreiber, R. Silvotti, D. Steeghs, O. Toloza, S. Toonen, S. Torres, A. J. Weinberger, B. Zuckerman
Summary: We conducted a spectroscopic survey of 248 white dwarf candidates within a distance of 40 pc from the Sun, with 244 of them located in the Southern hemisphere. Using the Very Large Telescope and Southern Astrophysical Research Telescope, we confirmed a total of 246 white dwarfs, with 209 having no previously published spectra. Among the identified white dwarfs, 100 display hydrogen Balmer lines, 69 have featureless spectra, and two show only neutral helium lines. Additionally, we observed 35 magnetic white dwarfs through Zeeman splitting of their spectral lines.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
D. Mata Sanchez, M. R. Kennedy, C. J. Clark, R. P. Breton, V. S. Dhillon, G. Voisin, F. Camilo, S. Littlefair, T. R. Marsh, J. Stringer
Summary: By conducting multiband observations on six black widow systems, we obtained their light curves. Through analyzing the curves, we inferred the parameters of the binary systems and discovered some companion stars with high temperature and density. We found expected correlations as well as a puzzling one.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
S. G. Parsons, M. S. Hernandez, O. Toloza, M. Zorotovic, M. R. Schreiber, B. T. Gansicke, F. Lagos, R. Raddi, A. Rebassa-Mansergas, J. J. Ren, D. Koester
Summary: Virtually all binaries consisting of a white dwarf with a non-degenerate companion can be classified as close post-interaction systems or wide systems. Binaries with periods between these two extremes can provide valuable information about common envelope efficiency and alternative pathways in the creation of compact binaries. The discovery of three white dwarfs in binaries with evolved subgiant stars sheds light on the formation process of these systems and their future evolution.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
C. J. Clark, R. P. Breton, E. D. Barr, M. Burgay, T. Thongmeearkom, L. Nieder, S. Buchner, B. Stappers, M. Kramer, W. Becker, M. Mayer, A. Phosrisom, A. Ashok, M. C. Bezuidenhout, F. Calore, I Cognard, P. C. C. Freire, M. Geyer, J-M Griessmeier, R. Karuppusamy, L. Levin, P. Padmanabh, A. Possenti, S. Ransom, M. Serylak, V. Venkatraman Krishnan, L. Vleeschower, J. Behrend, D. J. Champion, W. Chen, D. Horn, E. F. Keane, L. Kuenkel, Y. Men, A. Ridolfi, V. S. Dhillon, T. R. Marsh, M. A. Papa
Summary: By conducting targeted survey using the Transients and Pulsars with MeerKAT (TRAPUM) Large Survey Project, we discovered 9 new millisecond pulsars, including 8 in binary systems. We obtained timing solutions for two pulsars, enabling the detection of gamma-ray pulsations. X-ray emission from PSR J1803-6707 was detected in the eROSITA all-sky survey data.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
C. J. Clark, M. Kerr, E. D. Barr, B. Bhattacharyya, R. P. Breton, P. Bruel, F. Camilo, W. Chen, I. Cognard, H. T. Cromartie, J. Deneva, V. S. Dhillon, L. Guillemot, M. R. Kennedy, M. Kramer, A. G. Lyne, D. Mata Sanchez, L. Nieder, C. Phillips, S. M. Ransom, P. S. Ray, M. S. E. Roberts, J. Roy, D. A. Smith, R. Spiewak, B. W. Stappers, S. Tabassum, G. Theureau, G. Voisin
Summary: A few missing photons in Fermi Gamma-ray Space Telescope observations provide reliable neutron star mass measurements in eclipsing millisecond pulsar binaries, ruling out ultramassive pulsars in the original Black Widow system. Spectroscopy of bright companions in black widow systems can determine their radial velocities and provide inclination-dependent pulsar mass estimates. Gamma-ray eclipses in spider systems, discovered through observations from the Fermi Large Area Telescope, strictly limit the binary inclination angle and provide robust, model-independent pulsar mass constraints.
Article
Astronomy & Astrophysics
D. Eappachen, P. G. Jonker, A. J. Levan, J. Quirola-Vasquez, M. A. P. Torres, F. E. Bauer, V. S. Dhillon, T. Marsh, S. P. Littlefair, M. E. Ravasio, M. Fraser
Summary: Fast X-ray Transients (FXTs) are short-duration X-ray flares with various possible origins. In this study, the X-ray light curve and spectrum, as well as deep optical imaging, of the FXT XRT 210423 were analyzed. No transient optical counterpart was found, but multiple candidate host galaxies were identified. Based on their properties, a binary neutron star merger is favored as the explanation for XRT 210423.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Odette Toloza, Boris T. Gansicke, Laura M. Guzman-Rincon, Tom R. Marsh, Paula Szkody, Matthias R. Schreiber, Domitilla de Martino, Monica Zorotovic, Kareem El-Badry, Detlev Koester, Felipe Lagos
Summary: Research suggests that white dwarfs that accrete from non-degenerate companions exhibit abnormal carbon and nitrogen abundances in their stellar components, indicating they may be descendants of supersoft X-ray binaries. Measuring the carbon-to-nitrogen abundance ratio can provide insights into their past evolution. By analyzing far-ultraviolet spectroscopy of the cataclysmic variable HS 0218 + 3229, it was found that the ratio of carbon-to-nitrogen is about one tenth of the solar value. Other elemental abundances were also estimated, and the system's past was reconstructed. The study predicts that HS 0218 + 3229 will evolve to a period minimum below 76.2 +/- 1 minutes for normal cataclysmic variables.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
M. Patel, B. P. Gompertz, P. T. O'Brien, G. P. Lamb, R. L. C. Starling, P. A. Evans, L. Amati, A. J. Levan, M. Nicholl, K. Ackley, M. J. Dyer, J. Lyman, K. Ulaczyk, D. Steeghs, D. K. Galloway, V. S. Dhillon, G. Ramsay, K. Noysena, R. Kotak, R. P. Breton, L. K. Nuttall, E. Palle, D. Pollacco
Summary: GRB 201015A is a peculiar low-luminosity, spectrally soft gamma-ray burst that is associated with a type Ic or Ic-BL supernova. It follows the Amati relation and exhibits exceptionally soft properties in terms of photon index and spectral peak energy, similar to other GRBs sharing these characteristics.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Alex J. Brown, Steven G. Parsons, Jan van Roestel, Alberto Rebassa-Mansergas, Elme Breedt, Vik S. Dhillon, Martin J. Dyer, Matthew J. Green, Paul Kerry, Stuart P. Littlefair, Thomas R. Marsh, James Munday, Ingrid Pelisoli, David Sahman, James F. Wild
Summary: Wide-field time-domain photometric sky surveys have discovered a large number of eclipsing white dwarf plus M dwarf binaries, providing valuable information and insights into astrophysics. Precise follow-up observations are crucial to fully understand and utilize these systems. In this study, we present the first results of a high-speed multiband photometric follow-up program, which allows us to measure temperatures, masses, and radii of the components with improved precision. We also made interesting discoveries, such as sub-stellar secondaries and strongly magnetic white dwarfs. Additionally, we found the first pulsating white dwarfs in detached and eclipsing post-common-envelope binaries.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Ingrid Pelisoli, T. R. Marsh, David A. H. Buckley, I. Heywood, Stephen. B. Potter, Axel Schwope, Jaco Brink, Annie Standke, P. A. Woudt, S. G. Parsons, M. J. Green, S. O. Kepler, James Munday, A. D. Romero, E. Breedt, A. J. Brown, V. S. Dhillon, M. J. Dyer, P. Kerry, S. P. Littlefair, D. I. Sahman, J. F. Wild
Summary: White dwarf stars are common and often found in binaries, providing important insights into binary formation and evolution. The two remarkable systems, AR Scorpii and J191213.72-441045.1, exhibit pulsed emission and challenging theoretical models.
Article
Astronomy & Astrophysics
Napaporn A-thano, Supachai Awiphan, Ing-Guey Jiang, Eamonn Kerins, Akshay Priyadarshi, Iain McDonald, Yogesh C. Joshi, Thansuda Chulikorn, Joshua J. C. Hayes, Stephen Charles, Chung-Kai Huang, Ronnakrit Rattanamala, Li-Chin Yeh, Vik S. Dhillon
Summary: In this study, we analyzed the transit-timing variation and planetary atmosphere of the Neptune-mass planet HAT-P-26 b, finding a potential additional planet and determining the water content and temperature of its atmosphere.
ASTRONOMICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Diogo Belloni, Matthias R. Schreiber
Summary: This study demonstrates that cataclysmic variables (CVs) with evolved donors are likely progenitors of AM CVn binaries. It is found that if the donor develops a significant helium core prior to mass transfer, the surface hydrogen abundance of AM CVn binaries will substantially decrease and become undetectable. Additionally, the CV formation channel can explain the observed AM CVn binaries with low mass and bloated donor stars.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
J. Farihi, J. J. Hermes, S. P. Littlefair, I. D. Howarth, N. Walters, S. G. Parsons
Summary: This paper reports the discovery of dipolar surface spots in two cool magnetic white dwarfs with Balmer emission lines using ULTRACAM, while a third system exhibits a single spot, similar to the prototype GD 356. The light curves of these stars are modelled with simple, circular, isothermal dark spots, and the amplitudes of the multiband photometric variability are larger than that observed in the prototype GD 356. These findings support the interpretation that some magnetic white dwarfs generate intrinsic chromospheres as they cool and that no external source is responsible for the observed temperature inversion.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Keith Inight, Boris T. Gaensicke, Elme Breedt, Henry T. Israel, Stuart P. Littlefair, Christopher J. Manser, Tom R. Marsh, Tim Mulvany, Anna Francesca Pala, John R. Thorstensen
Summary: We present a catalogue of 507 cataclysmic variables (CVs) observed in SDSS I to IV, including 70 new classifications. This sample provides unbiased space densities and period distributions for different CV sub-types. The study also reports on peculiar CVs, period bouncers, and CVs with large changes in accretion rates. The catalogue and material included in it will be useful for observational population studies of CVs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
