Search Publications
Orbits of Six Triple Systems
Tokovinin, Andrei
Joint analysis of position measurements and radial velocities of six triple stellar systems is conducted to determine their inner and/or outer orbits. Accumulation of such data is needed to study the architecture of stellar hierarchies and its relation to the formation mechanisms. The inner periods in the six systems (HIP 11783, 64836, 72423, 8472…
Unveiling the Origins and Dynamics of the Hierarchical Triple Star System CN Lyn
Bakış, Volkan; Bilir, Selçuk; Alan, Neslihan +3 more
In this study, we present a detailed analysis of CN Lyn, an overlooked triple star system, by combining spectroscopic data from the literature, photometric Transiting Exoplanet Survey Satellite data, and kinematic techniques. We updated the fundamental parameters of the known eclipsing components in the system with high precision. The chemical com…
TESS Hunt for Young and Maturing Exoplanets (THYME). XII. A Young Mini-Neptune on the Upper Edge of the Radius Valley in the Hyades Cluster
Vanderburg, Andrew; Quinn, Samuel N.; Howell, Steve B. +19 more
We present the discovery and characterization of TOI-4364b, a young mini-Neptune in the tidal tails of the Hyades cluster, identified through TESS transit observations and ground-based follow-up photometry. The planet orbits a bright M dwarf (K = 9.1 mag) at a distance of 44 pc, with an orbital period of 5.42 days and an equilibrium temperature of…
Multiple Populations of the Large Magellanic Cloud Globular Cluster NGC 2257: No Major Environmental Effect on the Formation of Multiple Populations of Old Globular Clusters in the Large Magellanic Cloud
Kim, Hwihyun; Kim, Hak-Sub; Lee, Jae-Woo +3 more
How the environment of the host galaxy affects the formation of multiple populations (MPs) in globular clusters (GCs) is one of the outstanding questions in near-field cosmology. To understand the true nature of the old GC MPs in the Large Magellanic Cloud (LMC), we study the Ca–CN–CH photometry of the old metal-poor LMC GC NGC 2257. We find the p…
Distributions of Wide Binary Stars in Theory and in Gaia Data. I. Generalized Ambartsumian (1937) Approach and the Family of Power-law Distributions of Eccentricity
Makarov, Valeri V.
The orbital parameter space of wide, weakly bound binary stars has been shaped by the still poorly known circumstances of their formation, as well as by subsequent dynamical evolution in parent clusters and in the field. The advance of the Gaia mission astrometry takes statistical studies of wide stellar systems to an unprecedented level of precis…
Demographics of M Dwarf Binary Exoplanet Hosts Discovered by TESS
Lester, Kathryn V.; Schlieder, Joshua E.; Howell, Steve B. +15 more
M dwarfs have become increasingly important in the detection of exoplanets and the study of Earth-sized planets and their habitability. However, 20%–30% of M dwarfs have companions that can impact the formation and evolution of planetary systems. We use high-resolution imaging and Gaia astrometry to detect stellar companions around M dwarf exoplan…
Finite-lens Effect on Self-lensing in Detached White Dwarfs-main Sequence Binary Systems
Sajadian, Sedighe; Fatheddin, Hossein
In edge-on and detached binary systems, including a white dwarf (WD) and a main-sequence (MS) star system (or WDMS), when the source star is passing behind the compact companion its light is bent and magnified. Meanwhile, some part of its image's area is obscured by the WD's disk. These two effects occur simultaneously, and the observer receives t…
Astrometric Calibration of MagAO-X with Updated Solutions for HD 165054 Field Stars
Guyon, Olivier; Close, Laird M.; Males, Jared R. +13 more
MagAO-X is a recently commissioned extreme adaptive optics instrument for the Magellan Clay 6.5 m telescope at Las Campanas Observatory in Chile. MagAO-X had first light in 2019 and subsequent commissioning observations in 2022 and 2023. An essential step for the commissioning of any new instrument is the calibration of the conversion of detector …
Preparing for the Early eVolution Explorer: Characterizing the Photochemical Inputs and Transit Detection Efficiencies of Young Planets Using Multiwavelength Flare Observations by TESS and Swift
MacGregor, Meredith A.; Cody, Ann Marie; Vega, Laura D. +6 more
Ultraviolet flare emission can drive photochemistry in exoplanet atmospheres and even serve as the primary source of uncertainty in atmospheric retrievals. Additionally, flare energy budgets are not well understood due to a paucity of simultaneous observations. We present new near-UV (NUV) and optical observations of flares from three M dwarfs obt…
Two Earth-size Planets and an Earth-size Candidate Transiting the nearby Star HD 101581
Butler, R. Paul; Vanderburg, Andrew; Brahm, Rafael +43 more
We report the validation of multiple planets transiting the nearby (d = 12.8 pc) K5V dwarf HD 101581 (GJ 435, TOI–6276, TIC 397362481). This system consists of at least two Earth-size planets whose orbits are near a mutual 4:3 mean-motion resonance, HD 101581 b (