Search Publications
Dynamical Evolution of Four Old Galactic Open Clusters Traced by Their Constituent Stars with Gaia DR3
Vaidya, Kaushar; Rao, Khushboo K.; Agarwal, Manan +2 more
We investigate the evolutionary stages of four open clusters—Berkeley 39, Collinder 261, NGC 6819, and NGC 7789—of ages ranging from 1.6 to 6 Gyr. These clusters have previously been classified into dynamically young and intermediate age groups based on the segregation level of BSS with respect to red-giant-branch stars and main-sequence stars, re…
The Correlation Between Dust and Gas Contents in Molecular Clouds
Li, Guang-Xing; Chen, Bing-Qiu; Li, Rui-Zhi +3 more
Molecular clouds are regions of dense gas and dust in space where new stars and planets are born. There is a strong correlation between the distribution of dust and molecular gas in molecular clouds. The present work focuses on the three-dimensional morphological comparisons between dust and gas in 567 molecular clouds identified in a previously p…
Verification of Astrometrically Accelerating Stars from Hipparcos and Gaia. I. Methodology and Application to HIP 44842
Tokovinin, Andrei; Makarov, Valeri V.
A large number of candidate binary stars with apparent acceleration on the sky has emerged from analysis of astrometric data collected by the Hipparcos, Tycho-2, and Gaia space missions. Although the apparent acceleration can serve as a relatively reliable indicator of binarity, it provides scarce information about the orbital and physical paramet…
Spectroscopic Follow-up on Potential Magnetic Cataclysmic Variables
Littlefield, Colin; Szkody, Paula; Rich, R. Michael +8 more
Spectroscopic observations of nine cataclysmic variables that have been postulated to contain magnetic white dwarfs were obtained to further characterize their classifications, orbital parameters, inclinations, and/or accretion properties. Zwicky Transient Facility (ZTF) and Transiting Exoplanet Survey Satellite (TESS) data were also used when ava…
Casting Light on Degeneracies: A Comprehensive Study of Lightcurve Variations in Microlensing Events OGLE-2017-BLG-0103 and OGLE-2017-BLG-0192
Shah, Sarang
This study investigates orbital parallax in gravitational microlensing events, focusing on OGLE-2017-BLG-0103 and OGLE-2017-BLG-0192. For events with timescales ≤60 days, a Jerk-Parallax degeneracy arises due to high Jerk velocity (
Spectroscopic and Photometric Confirmation of 3 Globular and 14 Intermediate-age Clusters in the Irr II Galaxy NGC 3077
Mayya, Y. D.; Rosa-González, D.; Rodríguez-Merino, L. H. +4 more
We present the results from spectroscopic and photometric analysis of 17 globular cluster (GC) candidates in the Irr II galaxy NGC 3077. The GC candidates were selected on the Hubble Space Telescope images and were cleaned of foreground Galatic stars using the GAIA parameters. We carried out aperture photometry using the multiband archival images …
Two Long-period Giant Planets around Two Giant Stars: HD 112570 and HD 154391
Zhao, Gang; Wang, Wei; Song, Nan +24 more
We present the discoveries of two giant plants orbiting the red-giant-branch star HD 112570 and the red-clump star HD 154391, based on the radial-velocity (RV) measurements from the Xinglong station and Okayama Astrophysical Observatory. Spectroscopic and asteroseismic analyses suggest that HD 112570 has a mass of 1.15 ± 0.12 M ☉, a rad…
A Perfect Tidal Storm: HD 104067 Planetary Architecture Creating an Incandescent World
Kane, Stephen R.; Howard, Andrew W.; Fetherolf, Tara +5 more
The discovery of planetary systems beyond the solar system has revealed a diversity of architectures, most of which differ significantly from our system. The initial detection of an exoplanet is often followed by subsequent discoveries within the same system as observations continue, measurement precision is improved, or additional techniques are …
Searching for Hypercompact Star Clusters in the Milky Way Using LAMOST and Gaia
Niu, Zexi; Yuan, Haibo; Zhang, Huawei +2 more
During the early merger of the Milky Way, intermediate-mass black holes (BHs) in merged dwarf galaxies may have been ejected from the center of their host galaxies due to gravitational waves, carrying some central stars along. This process can lead to the formation of hypercompact star clusters, potentially hosting BHs in the mass range of 10…
Trials and Tribulations in the Reanalysis of KELT-24 b: A Case Study for the Importance of Stellar Modeling
Vanderburg, Andrew; Stassun, Keivan G.; Wittenmyer, Robert A. +21 more
We present a new analysis of the KELT-24 system, comprising a well-aligned hot Jupiter, KELT-24 b, and a bright (V = 8.3), nearby (d = 96.9 pc) F-type host star. KELT-24 b was independently discovered by two groups in 2019, with each reporting best-fit stellar parameters that were notably inconsistent. Here, we present three independent analyses o…