Publications (15)
Searching for GEMS: TOI-5688 A b, a low-density giant orbiting a high-metallicity early M-dwarf
Varghese Reji, Shubham Kanodia, Joe Ninan +31
We present the discovery of a low-density planet orbiting the high-metallicity early M-dwarf TOI-5688 A b. This planet was characterized as part of the search for transiting giant…
Searching for GEMS: Discovery of the Nearby Post-Common-Envelope Binary System TIC-460388167
Alexandra Boone, Henry A. Kobulnicky, Caleb I. Cañas +11
Short-period white dwarf+main-sequence binaries are Post-Common-Envelope Binaries (PCEB) that have survived a common envelope phase. Such systems, if detached and eclipsing, enable…
TOI-1259Ab: A Warm Jupiter Orbiting a K-dwarf White-Dwarf Binary is on a Well-aligned Orbit
Hugo Veldhuis, Juan I. Espinoza-Retamal, Gudmundur Stefansson +21
The evolution of one member of a stellar binary into a white dwarf has been proposed as a mechanism that triggers the formation of close-in gas giant planets. The star's asymmetric…
Hot water emission during an outburst on a classical T Tauri star
Zhen Guo, Javier Osses, Vitor Fermiano +34
In this paper, we present observations of an eruptive young star in the Rosette Nebula, identified by the Gaia Science Alerts system using Gaia time series data. We aim to investig…
A young progenitor for the most common planetary systems in the Galaxy
John H. Livingston, Erik A. Petigura, Trevor J. David +39
The Galaxy's most common known planetary systems have several Earth-to-Neptune-size planets in compact orbits. At small orbital separations, larger planets are less common than the…
A Mini-Neptune and a Venus-Zone Planet in the Radius Valley Orbiting the Nearby M2-dwarf TOI-1266: Validation with the Habitable-zone Planet Finder
Gudmundur Stefansson, Ravi Kopparapu, Andrea Lin +26
We report on the validation of two planets orbiting the nearby (36pc) M2 dwarf TOI-1266 observed by the TESS mission. The inner planet is sub-Neptune-sized ($R=2.46 \pm 0.08 R_\opl…
An Earth-Sized Planet in a 5.4h Orbit Around a Nearby K dwarf
Kaya Han TaÅ, Gudmundur Stefansson, Syarief N. M. Fariz +25
We present the discovery and confirmation of the ultra-short period (USP) planet TOI-2431 b orbiting a nearby ( pc) late K star ( = $4109 \pm 28 \, {\rm…
A close-in puffy Neptune with hidden friends: The enigma of TOI 620
Michael A. Reefe, Rafael Luque, Eric Gaidos +82
We present the validation of a transiting low-density exoplanet orbiting the M2.5 dwarf TOI 620 discovered by the NASA TESS mission. We utilize photometric data from both TESS and…
Stellar Activity Manifesting at a One Year Alias Explains Barnard b as a False Positive
Jack Lubin, Paul Robertson, Gudmundur Stefansson +17
Barnard's star is among the most studied stars given its proximity to the Sun. It is often considered Radial Velocity (RV) standard for fully convective stars due to its RV s…
Searching for GEMS: Discovery and Characterization of Two Brown Dwarfs Around M Dwarfs
Alexander Larsen, Tera N. Swaby, Henry A. Kobulnicky +17
Brown dwarfs bridge the gap between stars and planets, providing valuable insight into both planetary and stellar formation mechanisms. Yet the census of transiting brown dwarf com…
An extreme test case for planet formation: a close-in Neptune orbiting an ultracool star
Gudmundur Stefansson, Suvrath Mahadevan, Yamila Miguel +27
In current theories of planet formation, close-orbiting planets as massive as Neptune are expected to be very rare around low-mass stars. We report the discovery of a Neptune-mass…
Gaia-4b and 5b: Radial Velocity Confirmation of Gaia Astrometric Orbital Solutions Reveal a Massive Planet and a Brown Dwarf Orbiting Low-mass Stars
Gudmundur Stefansson, Suvrath Mahadevan, Joshua Winn +31
Gaia astrometry of nearby stars is precise enough to detect the tiny displacements induced by substellar companions, but radial velocity data are needed for definitive confirmation…
Machine Learning for Radial Velocity Analysis I: Vision Transformers as a Robust Alternative for Detecting Planetary Candidates
Anoop Gavankar, Tanish Mittal, Joe Ninan +1
Extreme precision radial velocity (EPRV) surveys usually require extensive observational baselines to confirm planetary candidates, making them resource-intensive. Traditionally, p…
Improving the Thermal Stability of a CCD Through Clocking
Cullen H. Blake, Dan Li, Joseph R. Tufts +6
Modern precise radial velocity spectrometers are designed to infer the existence of planets orbiting other stars by measuring few-nm shifts in the positions of stellar spectral lin…
NEID Reveals that The Young Warm Neptune TOI-2076 b Has a Low Obliquity
Robert C. Frazier, Gudmundur Stefansson, Suvrath Mahadevan +27
TOI-2076 b is a sub-Neptune-sized planet () that transits a young () bright () K-dwarf hosting a system of three transiting…