Search Publications
KIC 9028474: A Long-period Eclipsing Binary on a Highly Eccentric Orbit
Özdarcan, Orkun
We present a comprehensive analysis of a very long-period (124.93669 days) eclipsing binary KIC 9028474, which is composed of F9V+G1V components on a highly eccentric (e = 0.82029) orbit. Masses and radii of the primary and the secondary components are M 1 = 1.18 ± 0.04 M ⊙, M 2 = 1.04 ± 0.03 M ⊙, R
A Reinforcement Learning-Based Follow-up Framework
Astudillo, Javiera; Protopapas, Pavlos; Pichara, Karim +1 more
Classification and characterization of variable and transient phenomena are critical for astrophysics and cosmology. Given the volume of nightly data produced by ongoing and future surveys such as LSST, it is critical to develop automatic tools that assist in observation decision-making, maximizing scientific output without resource wastage. We pr…
New Insights on 30 Dor B Revealed by High-quality Multiwavelength Observations
Liu, Sheng-Yuan; Chu, You-Hua; Ueda, Shutaro +4 more
The supernova remnant (SNR) 30 Dor B is associated with the H II region ionized by the OB association LH99. The complex interstellar environment has made it difficult to study the physical structure of this SNR. We have used Hubble Space Telescope Hα images to identify SNR shocks and deep Chandra X-ray observations to detect faint diffuse emission…
An Investigation of New Brown Dwarf Spectral Binary Candidates From the Backyard Worlds: Planet 9 Citizen Science Initiative
Meisner, Aaron M.; Kirkpatrick, J. Davy; Burgasser, Adam J. +9 more
We present three new brown dwarf spectral-binary candidates: CWISE J072708.09-360729.2, CWISE J103604.84-514424.4, and CWISE J134446.62-732053.9, discovered by citizen scientists through the Backyard Worlds: Planet 9 project. Follow-up near-infrared spectroscopy shows that each of these objects is poorly fit by a single near-infrared standard. We …
The Kinematics of the Young Stellar Population in the W5 Region of the Cassiopeia OB6 Association: Implication for the Formation Process of Stellar Associations
Lim, Beomdu; Yun, Hyeong-Sik; Park, Byeong-Gon +3 more
The star-forming region W5 is a major part of the Cassiopeia OB6 association. Its internal structure and kinematics may provide hints of the star formation process in this region. Here, we present a kinematic study of young stars in W5 using the Gaia data and our radial velocity data. A total 490 out of 2000 young stars are confirmed as members. T…
A Six Year, Low-resolution, Multibroadband Transit Photometry Study of HD 189733b
Piccone, Ashley N.; Kobulnicky, Henry A.; Jang-Condell, Hannah +13 more
Transmission spectroscopy offers an invaluable opportunity to characterize the atmospheres of exoplanets. We present new ground-based optical transmission spectra of the hot Jupiter HD 189733b, derived from nine transits observed over a six year time span (2016-2021) using near-simultaneous $u^{\prime} g^{\prime} r^{\prime} i^{\prime} $ broadband …
Monitoring Hα Emission from the Wide-orbit Brown-dwarf Companion FU Tau B
Bowler, Brendan P.; Close, Laird M.; Wu, Ya-Lin +5 more
Monitoring mass accretion onto substellar objects provides insights into the geometry of the accretion flows. We use the Lulin One-meter Telescope to monitor Hα emission from FU Tau B, a ~19 M Jup brown-dwarf companion at 5.″7 (719 au) from the host star, for six consecutive nights. This is the longest continuous Hα monitoring for a sub…
33 New Stellar Angular Diameters from the NPOI, and Nearly 180 NPOI Diameters as an Ensemble
Stone, Jordan M.; von Braun, Kaspar; Schmitt, Henrique R. +2 more
We present new angular diameter measurements for 33 stars from the Navy Precision Optical Interferometer, reaching uncertainties on the limb-darkened diameter of 2% or less for 21 targets. We also determined the physical radius, bolometric flux, luminosity, and effective temperature for each star. Our sample is a mix of giant, subgiant, and dwarf …
UV Spectral Characterization of Low-mass Stars with AstroSat UVIT for Exoplanet Applications: The Case Study of HIP 23309
Ranjan, Sukrit; Narang, Mayank; Pineda, J. Sebastian +1 more
Characterizing rocky exoplanet atmospheres is a key goal of exoplanet science, but interpreting such observations will require understanding the stellar ultraviolet (UV) irradiation incident on the planet from its host star. Stellar UV mediates atmospheric escape, photochemistry, and planetary habitability, and observations of rocky exoplanets can…
Correlations in Chromospheric and Coronal Activity Indicators of Giant Stars
Crandall, Sara; Smith, Graeme H.
The main goal of this paper is to use ultraviolet photometry from the Galaxy Evolution Explorer (GALEX) satellite to study chromospheric activity among red giant and core-helium-burning (CHeB) stars. Correlations are sought between several chromospheric and coronal activity indicators for giants that were detected in soft X-rays by the ROentgen SA…