activity
20202026
most citedSpeckle Observations of TESS Exoplanet Host Stars. II. Stellar Companions at 1-1000 AU and Implications for Small Planet Detection

89 citations · 331 across the 26 of their papers we have counts for

collaborators

26 papers

astro-ph.IM2026

Early Exploration of the Scientific Discovery Space for the Habitable Worlds Observatory

Courtney D. Dressing, Danica Adams, Evelyne Alecian +324

The Habitable Worlds Observatory (HWO) is a future NASA flagship mission concept identified by the Astro2020 Decadal Survey as the highest priority for large space missions. HWO sh…

astro-ph.SR2026

Speckle Interferometry of 25 Gaia Two-Parameter Potential Binaries

Paul McCudden, Russell Genet, John Major +20

Gaia two-parameter (G2P) stars have cumulative errors in parallax and proper motion so great that only their mean positions were reported in DR3. One potential cause of these high…

astro-ph.SR2026

Paving the Road to the Habitable Worlds Observatory with High-Resolution Imaging I: New and Archival Speckle Observations of Potential HWO Target Stars

Zachary D. Hartman, Catherine A. Clark, Michael B. Lund +15

One of the key goals of the Habitable Worlds Observatory (HWO) is to directly image about 25 potentially habitable exoplanets and determine their properties. This challenge will re…

astro-ph.EP2025

TOI-283 b: A transiting mini-Neptune in a 17.6-day orbit discovered with TESS and ESPRESSO

F. Murgas, E. Pallé, A. Suárez Mascareño +51

Super-Earths and mini-Neptunes are missing from our Solar System, yet they appear to be the most abundant planetary types in our Galaxy. A detailed characterization of key planets…

astro-ph.SR2025★ 4 cited

A search for Be stars in multiple systems within the solar neighborhood

V. M. Kalari, R. Salinas, C. Saez-Carvajal +9

Be stars are widely considered to be the product of binary interaction. However, whether all Be stars are formed via binary interaction is unclear, and detailed estimates of the mu…

astro-ph.SR2025

Resolving the Unresolved: Using NESSI to Search for Unresolved Companions in Low-mass Disk Wide Binaries

Zachary D. Hartman, Gerard van Belle, Sébastien Lépine +2

Stellar systems consisting of three or more stars are not an uncommon occurrence in the Galaxy. Nearly 50% of solar-type wide binaries with separations >1000 au are actually higher…

astro-ph.IM2025

Nearly a Decade of Groundbreaking Speckle Interferometry at the International Gemini Observatory

Steve B. Howell, Clara E. Martínez-Vázquez, Elise Furlan +8

Since its inception, speckle interferometry has revolutionized high-resolution astronomical imaging, overcoming atmospheric challenges to achieve the diffraction limits of telescop…

astro-ph.GA2025

Near-Infrared Spectroscopy with IGRINS-2 for Studying Multiple Stellar Populations in Globular Clusters

Dongwook Lim, Young-Wook Lee, Sol Yun +53

Recent advancements in near-infrared (NIR) spectroscopy have opened new opportunities for studying multiple stellar populations in globular clusters (GCs), particularly for newly d…

astro-ph.EP2025★ 4 cited

An Early Look at the Performance of IGRINS-2 at Gemini-North with Application to the ultrahot Jupiter, WASP-33 b

Yeon-Ho Choi, Ueejeong Jeong, Jae-Joon Lee +56

Ground-based high-resolution spectroscopy enables precise molecular detections and velocity-resolved atmospheric dynamics, offering a distinct advantage over low-resolution methods…

astro-ph.EP2024★ 1 cited

GJ 238 b: A 0.57 Earth Radius Planet Orbiting an M2.5 Dwarf Star at 15.2 pc

Evan Tey, Avi Shporer, Zifan Lin +30

We report the discovery of the transiting planet GJ 238 b, with a radius of R ( times the radius of Mars) and an orbital period of 1.74 da…

astro-ph.SR2024

Detecting New Visual Binaries in Gaia DR3 with Gaia and Two Micron All Sky Survey (2MASS) Photometry II. Speckle Observations of 16 Low-Separation Systems

Ilija Medan, Sébastien Lépine, Zachary Hartman +1

Here we present speckle observations of 16 low-separation ( AU) high probability candidate binaries from the catalog by Medan et al., where secondaries typically lack astrome…

astro-ph.SR2024

The POKEMON Speckle Survey of Nearby M Dwarfs. III. The Stellar Multiplicity Rate of M Dwarfs within 15 pc

Catherine A. Clark, Gerard T. van Belle, Elliott P. Horch +8

M dwarfs are ubiquitous in our galaxy, and the rate at which they host stellar companions, and the properties of these companions, provides a window into the formation and evolutio…

astro-ph.GA2023★ 17 cited

Probing the early Milky Way with GHOST spectra of an extremely metal-poor star in the Galactic disk

Anya Dovgal, Kim A. Venn, Federico Sestito +31

Pristine_183.6849+04.8619 (P1836849) is an extremely metal-poor ([Fe/H]) star on a prograde orbit confined to the Galactic disk. Such stars are rare and may have their…

astro-ph.HE2023★ 1 cited

Limits on Optical Counterparts to the Repeating FRB 20180916B from High-speed Imaging with Gemini-N/'Alopeke

Charles D. Kilpatrick, Nicolas Tejos, J. Xavier Prochaska +6

We report on contemporaneous optical observations at ~10 ms timescales from the fast radio burst (FRB) 20180916B of two repeat bursts (FRB 20201023, FRB 20220908) taken with the 'A…

astro-ph.SR2023

The POKEMON Speckle Survey of Nearby M Dwarfs. II. Observations of 1125 Targets

Catherine A. Clark, Gerard T. van Belle, Elliott P. Horch +7

Stellar multiplicity is correlated with many stellar properties, yet multiplicity measurements have proven difficult for the M dwarfs -- the most common type of star in our galaxy…

astro-ph.SR2023

SPLUS J142445.34-254247.1: An R-Process Enhanced, Actinide-Boost, Extremely Metal-Poor star observed with GHOST

Vinicius M. Placco, Felipe Almeida-Fernandes, Erika M. Holmbeck +33

We report on the chemo-dynamical analysis of SPLUS J142445.34-254247.1, an extremely metal-poor halo star enhanced in elements formed by the rapid neutron-capture process. This sta…

astro-ph.EP2023★ 57 cited

The two rings of (50000) Quaoar

C. L. Pereira, B. Sicardy, B. E. Morgado +66

Quaoar is a classical Trans-Neptunian Object (TNO) with an area equivalent diameter of 1,100 km and an orbital semi-major axis of 43.3 astronomical units. Based on stellar occultat…

astro-ph.EP2022

TFAW survey II: 6 Newly Validated Planets and 13 Planet Candidates from K2

D. del Ser, O. Fors, M. del Alcázar +7

Searching for Earth-sized planets in data from Kepler's extended mission (K2) is a niche that still remains to be fully exploited. The TFAW survey is an ongoing project that aims t…

astro-ph.SR2022★ 7 cited

Vetting the Lobster Diagram: Searching for Unseen Companions in Wide Binaries using NASA Space Exoplanet Missions

Zachary Hartman, Sébastien Lépine, Ilija Medan

Over the past decade, the number of known wide binary systems has exponentially expanded thanks to the release of data from the Gaia Mission. Some of these wide binary systems are…

astro-ph.EP2021★ 1 cited

TOI 560 : Two Transiting Planets Orbiting a K Dwarf Validated with iSHELL, PFS and HIRES RVs

Mohammed El Mufti, Peter P. Plavchan, Howard Isaacson +92

We validate the presence of a two-planet system orbiting the 0.15--1.4 Gyr K4 dwarf TOI 560 (HD 73583). The system consists of an inner moderately eccentric transiting mini-Neptune…

astro-ph.EP2021★ 50 cited

The young HD 73583 (TOI-560) planetary system: Two 10-M mini-Neptunes transiting a 500-Myr-old, bright, and active K dwarf

O. Barragán, D. J. Armstrong, D. Gandolfi +103

We present the discovery and characterisation of two transiting planets observed by \textit{TESS} in the light curves of the young and bright (V=9.67) star HD73583 (TOI-560). We pe…

astro-ph.SR2021★ 15 cited

Direct Measurements of Giant Star Effective Temperatures and Linear Radii: Calibration Against Spectral Types and V-K Color

Gerard T. van Belle, Kaspar von Braun, David R. Ciardi +8

We calculate directly determined values for effective temperature () and radius () for 191 giant stars based upon high resolution angular size measurements from opt…

astro-ph.SR2021★ 89 cited

Speckle Observations of TESS Exoplanet Host Stars. II. Stellar Companions at 1-1000 AU and Implications for Small Planet Detection

Kathryn V. Lester, Rachel A. Matson, Steve B. Howell +7

We present high angular resolution imaging observations of 517 host stars of TESS exoplanet candidates using the `Alopeke and Zorro speckle cameras at Gemini North and South. The s…

astro-ph.SR2021★ 11 cited

Bayesian Cross-Matching of High Proper Motion Stars in Gaia DR2 and Photometric Metallicities for 1.7 million K and M Dwarfs

Ilija Medan, Sébastien Lépine, Zachary Hartman

We present a Bayesian method to cross-match 5,827,988 high proper motion Gaia sources () to various photometric surveys: 2MASS, AllWISE, GALEX, RAVE, SDSS and…