Search Publications
WISE 2150-7520AB: A Very Low-mass, Wide Comoving Brown Dwarf System Discovered through the Citizen Science Project Backyard Worlds: Planet 9
Gonzales, Eileen C.; Meisner, Aaron M.; Burgasser, Adam J. +10 more
We report the discovery of WISE 2150-7520AB (W2150AB): a widely separated (∼341 au) very low-mass L1 + T8 co-moving system. The system consists of the previously known L1 primary 2MASS J21501592-7520367 and a newly discovered T8 secondary found at position 21:50:18.99-75:20:54.6 (MJD = 57947) using Wide-field Infrared Survey Explorer data via the …
The Evolution of the Inner Regions of Protoplanetary Disks
Calvet, Nuria; Lizano, Susana; Miller, Christopher J. +6 more
We present a study of the evolution of the inner few astronomical units of protoplanetary disks around low-mass stars. We consider nearby stellar groups with ages spanning from 1 to 11 Myr, distributed into four age bins. Combining PANSTARSS photometry with spectral types, we derive the reddening consistently for each star, which we use (1) to mea…
Solar Flare Arcade Modeling: Bridging the Gap from 1D to 3D Simulations of Optically Thin Radiation
Polito, Vanessa; Kerr, Graham S.; Allred, Joel C.
Solar flares are 3D phenomena, but modeling a flare in 3D, including many of the important processes in the chromosphere, is a computational challenge. Accurately modeling the chromosphere is important, even if the transition region and corona are the areas of interest, due to the flow of energy, mass, and radiation through the interconnected laye…
The binary content of multiple populations in NGC 3201
Dreizler, S.; Bastian, N.; Latour, M. +7 more
We investigate the binary content of the two stellar populations that coexist in the globular cluster NGC 3201. Previous studies of binary stars in globular clusters have reported higher binary fractions in their first populations (P1, having field-like abundances) compared to their second populations (P2, having anomalous abundances). This is int…
H- and Dissociation in Ultra-hot Jupiters: A Retrieval Case Study of WASP-18b
Madhusudhan, Nikku; Gandhi, Siddharth; Mandell, Avi
Atmospheres of a number of ultra-hot Jupiters (UHJs) with temperatures ≳2000 K have been observed recently. Many of these planets show largely featureless thermal spectra in the near-infrared observed with the HST WFC3 spectrograph (1.1-1.7 µm) even though this spectral range contains strong H2O opacity. Recent works have proposed…
Lifetime of short-period binaries measured from their Galactic kinematics
Zakamska, Nadia L.; Hwang, Hsiang-Chih
As a significant fraction of stars are in multiple systems, binaries play a crucial role in stellar evolution. Among short-period (<1 d) binary characteristics, age remains one of the most difficult to measure. In this paper, we constrain the lifetime of short-period binaries through their kinematics. With the kinematic information from Gaia Da…
A Word to the WISE: Confusion is Unavoidable for WISE-selected Infrared Excesses
Debes, John H.; Gentile Fusillo, Nicola Pietro; Farihi, Jay +1 more
Stars with excess infrared radiation from circumstellar dust are invaluable for studies of exoplanetary systems, informing our understanding of processes of planet formation and destruction alike. All-sky photometric surveys have made the identification of dusty infrared excess candidates trivial, however, samples that rely on data from Wise Infra…
Probing the circumstellar medium 2.8 Gyr after the big bang: detection of Bowen fluorescence in the Sunburst arc
Castellano, M.; Grillo, C.; Brammer, G. B. +13 more
We discovered Bowen emission arising from a strongly lensed (i.e. with magnification factor µ > 20) source hosted in the Sunburst arc at z = 2.37. We claim this source is plausibly a transient stellar object and study the unique ultraviolet lines emerging from it. In particular, narrow (σv ≃ 40 km s-1) ionization lin…
Stellar parameter determination from photometry using invertible neural networks
Gennaro, Mario; Sabbi, Elena; Gouliermis, Dimitrios +7 more
Photometric surveys with the Hubble Space Telescope (HST) allow us to study stellar populations with high-resolution and deep coverage, with estimates of the physical parameters of the constituent stars being typically obtained by comparing the survey data with adequate stellar evolutionary models. This is a highly non-trivial task due to effects …
Cosmic evolution of star-forming galaxies to z ≃ 1.8 in the faint low-frequency radio source population
Prandoni, I.; Vaccari, M.; Mancuso, C. +4 more
We study the properties of star-forming galaxies selected at 610 MHz with the GMRT in a survey covering ∼1.86 deg2 down to a noise of ∼7.1 µJy beam-1. These were identified by combining multiple classification diagnostics: optical, X-ray, infrared, and radio data. Of the 1685 SFGs from the GMRT sample, 496 have spectros…