Article
Astronomy & Astrophysics
Alexis L. Quintana, Nicholas J. Wright
Summary: This study reexamines the existence and membership of the Cygnus OB associations, identifying six new associations with two resembling the historical Cyg OB2 and OB3. The properties of the new associations and their expansion trends are consistent with typical values for OB associations. Large-scale kinematic expansion patterns across the Cygnus region are attributed to feedback from previous generations of stars.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
I Shaposhnikov, A. Cherepashchuk, A. Dodin, K. Postnov
Summary: This article presents the results of new photometric and spectroscopic observations of the WN5 + O6 binary V444 Cyg and provides a detailed analysis of existing spectroscopy and photometry. The study determined the masses and orbit sizes of the components of V444 Cyg, as well as estimated the secular increase rate of the orbital period and the stellar wind mass-loss rate from the WR star.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
F-X Li, S-B Qian, J. Zhang, L-Y Zhu, E-G Zhao, W-P Liao
Summary: Based on the analysis of light curves and spectra from TESS, we have determined that V375 Cas is a semidetached binary undergoing mass transfer and a third body is causing cyclic variations. This discovery is significant for understanding stellar structures and evolution.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
A. Rainot, M. Reggiani, H. Sana, J. Bodensteiner, O. Absil
Summary: This study uses the Carina High-contrast Imaging Project of massive Stars (CHIPS) to explore the companion mass function of O-type stars in the Trumpler 14 cluster. The results show the detection of numerous companions within a range of approximately 360 astronomical units, but most of them cannot be distinguished as cluster members. One companion with a mass of 1.4 solar masses is identified, and differences in the overall mass function are observed due to contamination of K-band fluxes.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Mate Szilagyi, Maria Kun, Peter abraham, Gabor Marton
Summary: Using Gaia DR3 data, this study investigates the structure and kinematics of the Cepheus OB2 association and characterizes its star formation history, with particular focus on the Cepheus Bubble. Thirteen stellar groups belonging to Cep OB2 are identified using a clustering algorithm, with four older groups located inside the bubble and younger groups found on the periphery. The tangential velocities suggest different formation mechanisms, with some groups born in an expanding system of star-forming clouds and others formed due to collision with the expanding bubble.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
T. Van Reeth, J. Southworth, J. Van Beeck, D. M. Bowman
Summary: By studying the newly detected gravity-mode pulsations in V456 Cyg, the global stellar properties of this short-period eclipsing binary and the interaction between these pulsations and the tides are determined.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
C. N. Rodriguez, G. A. Ferrero, O. G. Benvenuto, R. Gamen, N. Morrell, R. H. Barba, J. Arias, P. Massey
Summary: A comprehensive study of the massive binary system HM1 8 was conducted, revealing orbital parameters, stellar characteristics, and attributing X-ray emission to stellar winds.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
O. Ozdarcan
Summary: By conducting light-curve analyses, two newly identified detached eclipsing binaries, HD96609 and HD303734, were found in the region of the richly populated open cluster NGC3532. HD96609 consists of two main sequence stars, while HD303734 is an interesting totally eclipsing binary.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
F. Comeron, N. Schneider, A. A. Djupvik
Summary: The study focuses on the young stellar populations associated with two isolated globules, DR 18 and ECX 6-21, irradiated by O-type stars. It reveals embedded populations in both globules, with differences in evolution between the two main star-forming sites in ECX 6-21.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
P. A. Kolaczek-Szymanski, A. Pigulski, G. Michalska, D. Mozdzierski, T. Rozanski
Summary: This study identified 20 massive heartbeat systems, with 7 exhibiting TEOs, using TESS data from the first 16 sectors and a sample of over 300 eccentric spectroscopic binaries. The results open up new possibilities for probing the interiors of massive stars and studying the interaction between pulsation and binarity in these systems.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Joachim M. Bestenlehner, Paul A. Crowther, Patrick S. Broos, Andrew M. T. Pollock, Leisa K. Townsley
Summary: In this study, spectroscopic analysis was conducted on the luminous X-ray source Mk 33Na in the Large Magellanic Cloud using new time-series spectroscopy. The analysis confirmed that Mk 33Na is a double-lined O-type spectroscopic binary with extreme physical properties, making it one of the highest mass binary systems in the LMC.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Tong Bao, Zhiyuan Li, Zhongqun Cheng
Summary: In this study, we used deep X-ray observations and recently available data to study periodic X-ray sources in the massive globular cluster 47 Tuc. We discovered 20 periodic signals among 18 X-ray sources, and found that the period distribution of cataclysmic variables (CVs) in 47 Tuc is significantly different from those found in other regions. This difference may be attributed to a higher fraction of non-magnetic CVs in 47 Tuc.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
S. Rosu, G. Rauw, Y. Naze, E. Gosset, C. Sterken
Summary: This study provides a consistent analysis of the apsidal motion in the binary system CPD-41 degrees 7742, and explains the discrepancy in periastron longitudes pointed out in past studies. Additionally, the analysis of HD 152218 suggests the need for enhanced mixing in stellar evolution models.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
J. Bodensteiner, H. Sana, C. Wang, N. Langer, L. Mahy, G. Banyard, A. de Koter, S. E. de Mink, C. J. Evans, Y. Gotberg, L. R. Patrick, F. R. N. Schneider, F. Tramper
Summary: Observations of massive stars in open clusters younger than 8 Myr show that a majority are in binary systems, most of which will interact during their life. Studying populations of massive stars older than 20 Myr allows us to probe the outcome of these interactions. The study in NGC330 reveals differences in spectroscopic binary fractions among stars of different evolutionary stages.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
S. Rosu, G. Rauw, M. Farnir, M-A Dupret, A. Noels
Summary: The measurement of apsidal motion in a binary system provides information about the internal structure of the stars. By analyzing the observations of the HD 152219 system, we determined its fundamental parameters and found that the system displays apsidal motion. The internal structure constant of the system suggests the need for enhanced mixing inside the stars.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Serge B. Dieterich, Andrew Simler, Todd J. Henry, Wei-Chun Jao
Summary: The study tested models of M-dwarf structure and evolution using optical spectroscopy, finding marginal agreement between evolutionary model predictions and observations, with some discrepancies in cases where the condition of coevality was not fully satisfied.
ASTRONOMICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Leonardo A. Paredes, Todd J. Henry, Samuel N. Quinn, Douglas R. Gies, Rodrigo Hinojosa-Goni, Hodari-Sadiki James, Wei-Chun Jao, Russel J. White
Summary: The study reports initial results of a large radial velocity survey of K dwarfs, identifying three new exoplanet candidates and confirming a hot Jupiter. Validation of technique through known exoplanets orbiting K dwarfs brings the total number of presented orbital solutions to 9.
ASTRONOMICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Tzvetelina A. Dimitrova, Kathryn F. Neugent, Philip Massey, Emily M. Levesque
Summary: Using archival near-IR photometry, the study identifies the brightest red supergiants in NGC 6822 and compares their physical properties with evolutionary model predictions. It concludes that the best fit is provided by the BPASS model, suggesting the presence of cool RSGs and a history of binary interaction. The study hopes to inspire further comparative RSG studies and improve understanding of evolutionary model predictions.
ASTRONOMICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Philip Massey, Kathryn F. Neugent, Trevor Z. Dorn-Wallenstein, J. J. Eldridge, E. R. Stanway, Emily M. Levesque
Summary: Despite previous estimates showing a decrease in the relative number of red supergiants and Wolf-Rayet stars with increasing metallicity, this study found good agreement between new observations and the single-star Geneva and binary BPASS models.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Erin Aadland, Philip Massey, D. John Hillier, Nidia Morrell
Summary: In this study, we conducted a spectral analysis of WC-type Wolf-Rayet stars in the Large Magellanic Cloud to address two important evolutionary questions: whether WO-type WR stars are more oxygen enriched than WC-type stars and whether WR stars evolve independently or require a close companion. The results suggest that these four WC4 stars could have formed through either binary or single-star evolution.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Michele L. Silverstein, Joshua E. Schlieder, Thomas Barclay, Benjamin J. Hord, Wei-Chun Jao, Eliot Halley Vrijmoet, Todd J. Henry, Ryan Cloutier, Veselin B. Kostov, Ethan Kruse, Jennifer G. Winters, Jonathan M. Irwin, Stephen R. Kane, Keivan G. Stassun, Chelsea Huang, Michelle Kunimoto, Evan Tey, Andrew Vanderburg, Nicola Astudillo-Defru, Xavier Bonfils, C. E. Brasseur, David Charbonneau, David R. Ciardi, Karen A. Collins, Kevin Collins, Dennis M. Conti, Ian J. M. Crossfield, Tansu Daylan, John P. Doty, Courtney D. Dressing, Emily A. Gilbert, Keith Horne, Jon M. Jenkins, David W. Latham, Andrew W. Mann, Elisabeth Matthews, Leonardo A. Paredes, Samuel N. Quinn, George R. Ricker, Richard P. Schwarz, Sara Seager, Ramotholo Sefako, Avi Shporer, Jeffrey C. Smith, Christopher Stockdale, Thiam-Guan Tan, Guillermo Torres, Joseph D. Twicken, Roland Vanderspek, Gavin Wang, Joshua N. Winn
Summary: Researchers have discovered the LHS 1678 (TOI-696) exoplanet system, which consists of two approximately Earth-sized planets and a likely astrometric brown dwarf. This finding contributes to understanding the formation and evolution of small, short-period exoplanets orbiting low-mass stars.
ASTRONOMICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Azmain H. Nisak, Russel J. White, Alexandra Yep, Todd J. Henry, Leonardo Paredes, Hodari-Sadiki James, Wei-Chun Jao
Summary: By using Gaia DR2 data and high-resolution spectroscopy, we have refined the membership lists of the IC 2391 and IC 2602 open clusters and confirmed many new candidate members, which is important for studying the early evolution of stars and planets.
ASTRONOMICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Maissa Salama, Carl Ziegler, Christoph Baranec, Michael C. Liu, Nicholas M. Law, Reed Riddle, Todd J. Henry, Jennifer G. Winters, Wei-Chun Jao, James Ou, Arcelia Hermosillo Ruiz
Summary: We conducted a census of nearby stars for companions using Robo-AO and detected 154 companion candidates. We confirmed physical association for 53 of them and found an additional 147 companions using Gaia EDR3. In total, we reported 301 companions, including 49 new discoveries. The study also provided multiplicity fractions for different spectral types of stars.
ASTRONOMICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Eliot Halley Vrijmoet, Andrei Tokovinin, Todd J. Henry, Jennifer G. Winters, Elliott Horch, Wei-Chun Jao
Summary: The preliminary results of a multiyear program mapping the orbits of M-dwarf multiples within 25 pc are presented. Observations conducted using speckle interferometry detect companions for 63% of the surveyed stars, including new companions for 76% of the subset selected from Gaia DR2. A total of 97 new stellar companions have been directly detected. This program aims to ultimately map complete orbits for nearby M dwarfs and provide key epochs for binary orbital determinations.
ASTRONOMICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Erin Aadland, Philip Massey, D. John Hillier, Nidia Morrell, Kathryn F. Neugent, J. J. Eldridge
Summary: The study reveals that WO-type WR stars, compared to WC-type WR stars, do have higher carbon content and lower helium content, supporting the notion that they are more evolved. However, there is no significant difference in oxygen content between WO and WC stars. This finding may provide an explanation for the previous inability to model this line accurately.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Kathryn Lester, Gail H. Schaefer, Francis C. Fekel, Douglas R. Gies, Todd J. Henry, Wei-Chun Jao, Leonardo A. Paredes, Hodari-Sadiki Hubbard-James, Christopher D. Farrington, Kathryn D. Gordon, S. Drew Chojnowski, John D. Monnier, Stefan Kraus, Jean-Baptiste Le Bouquin, Narsireddy Anugu, Theo Ten Brummelaar, Claire L. Davies, Tyler Gardner, Aaron Labdon, Cyprien Lanthermann, Benjamin R. Setterholm
Summary: We have presented the visual orbits of four spectroscopic binary stars using long baseline interferometry, and determined their stellar masses, distances, radii, and temperatures. By comparing the observed parameters to the predictions of stellar evolution models, we found that only one system fits well with the models.
ASTRONOMICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Bruce Margon, Nidia Morrell, Philip Massey, Kathryn F. F. Neugent, Robert Williams
Summary: This paper presents the final results of a search for stars in the Large Magellanic Cloud (LMC) using imaging and spectroscopy. The goal of the study is to identify and study [WC11] stars, the coolest of the low-mass Wolf-Rayet sequence, as well as a subset of central stars of planetary nebulae. The authors found several new members of this rare class and propose that the intensity ratio of the C ii doublet observed in their spectra can divide the objects into two distinct groups.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Wei-Chun Jao, Andrew A. Couperus, Eliot H. Vrijmoet, Nicholas J. Wright, Todd J. Henry
Summary: This study demonstrates the inaccuracies in mass estimation of a commonly used tau-mass relation based on Gaia Early Data Release 3. The findings highlight the importance of establishing multidimensional relations for more accurate estimation of convective turnover time in the era of large data sets.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Philip Massey, Kathryn F. Neugent, Sylvia Ekstroem, Cyril Georgy, Georges Meynet
Summary: Mass loss in red supergiants is episodic and determines their evolution and ultimate fate. The current Geneva evolutionary models mimic this episodic mass loss by enhancing the quiescent prescription rates when the star's outer layers exceed the Eddington luminosity. Observational tests show that the models with the enhanced mass-loss rates accurately predict the proportion of high-luminosity red supergiants, while models with lower mass-loss rates are ruled out. The upper luminosity limit of red supergiants is found to be log L L-circle dot similar to 5.4, regardless of metallicity.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Gregory A. Feiden, Khian Skidmore, Wei-Chun Jao
Summary: The Gaia M-dwarf gap is a significant underdensity of stars observed in the color-magnitude diagram, possibly caused by structural instabilities within stellar interiors due to nonequilibrium He-3 fusion. Synthetic models were able to reproduce the observed features of the gap, indicating its usefulness for testing the physics of M-dwarf stars.
ASTROPHYSICAL JOURNAL
(2021)
