185 citations · 1.1k across the 31 of their papers we have counts for
31 papers
TOI-3785 b: A Low-Density Neptune Orbiting an M2-Dwarf Star
Luke C. Powers, Jessica Libby-Roberts, Andrea S. J. Lin +19
Using both ground-based transit photometry and high-precision radial velocity (RV) spectroscopy, we confirm the planetary nature of TOI-3785 b. This transiting Neptune orbits an M2…
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…
TOI-5205 b: A Short-period Jovian Planet Transiting a Mid-M Dwarf
Shubham Kanodia, Suvrath Mahadevan, Jessica Libby-Roberts +27
We present the discovery of TOI-5205~b, a transiting Jovian planet orbiting a solar metallicity M4V star, which was discovered using Transiting Exoplanet Survey Satellite photometr…
GJ 3929: High Precision Photometric and Doppler Characterization of an Exo-Venus and its Hot, Mini-Neptune-mass Companion
Corey Beard, Paul Robertson, Shubham Kanodia +31
We detail the follow up and characterization of a transiting exo-Venus identified by TESS, GJ 3929b, (TOI-2013b) and its non-transiting companion planet, GJ 3929c (TOI-2013c). GJ 3…
TOI-1696 and TOI-2136: Constraining the Masses of Two Mini-Neptunes with HPF
Corey Beard, Paul Robertson, Shubham Kanodia +29
We present the validation of two planets orbiting M dwarfs, TOI-1696b and TOI-2136b. Both planets are mini-Neptunes orbiting nearby stars, making them promising prospects for atmos…
TOI-3757 b: A low density gas giant orbiting a solar-metallicity M dwarf
Shubham Kanodia, Jessica Libby-Roberts, Caleb I. Canas +32
We present the discovery of a new Jovian-sized planet, TOI-3757 b, the lowest density planet orbiting an M dwarf (M0V). It orbits a solar-metallicity M dwarf discovered using TESS…
Rotational modulation of spectroscopic Zeeman signatures in low-mass stars
Ryan C. Terrien, Allison Keen, Katy Oda +24
Accurate tracers of the stellar magnetic field and rotation are cornerstones for the study of M dwarfs and for reliable detection and characterization of their exoplanetary compani…
TOI-3714 b and TOI-3629 b: Two gas giants transiting M dwarfs confirmed with HPF and NEID
Caleb I. Cañas, Shubham Kanodia, Chad F. Bender +36
We confirm the planetary nature of two gas giants discovered by TESS to transit M dwarfs. TOI-3714 () is an M2 dwarf hosting a hot Jupiter ($M_p=0.70 \pm 0.03~\ma…
A hot Mars-sized exoplanet transiting an M dwarf
Caleb I. Cañas, Suvrath Mahadevan, William D. Cochran +21
We validate the planetary nature of an ultra-short period planet orbiting the M dwarf KOI-4777. We use a combination of space-based photometry from Kepler, high-precision, near-inf…
High resolution near-infrared spectroscopy of a flare around the ultracool dwarf vB 10
Shubham Kanodia, Lawrence W. Ramsey, Marissa Maney +20
We present high-resolution observations of a flaring event in the M8 dwarf vB 10 using the near-infrared Habitable zone Planet Finder (HPF) spectrograph on the Hobby Eberly Telesco…
The Warm Neptune GJ 3470b has a Polar Orbit
Gudmundur Stefansson, Suvrath Mahadevan, Cristobal Petrovich +34
The warm Neptune GJ 3470b transits a nearby (pc) bright slowly rotating M1.5-dwarf star. Using spectroscopic observations during two transits with the newly commissioned NEID…
A Search for Planetary Metastable Helium Absorption in the V1298 Tau System
Shreyas Vissapragada, Guðmundur Stefánsson, Michael Greklek-McKeon +28
Early in their lives, planets endure extreme amounts of ionizing radiation from their host stars. For planets with primordial hydrogen and helium-rich envelopes, this can lead to s…
TOI-532b: The Habitable-zone Planet Finder confirms a Large Super Neptune in the Neptune Desert orbiting a metal-rich M dwarf host
Shubham Kanodia, Gudmundur Stefansson, Caleb I. Canas +30
We confirm the planetary nature of TOI-532b, using a combination of precise near-infrared radial velocities with the Habitable-zone Planet Finder, TESS light curves, ground based p…
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…
Broadband stability of the Habitable Zone Planet Finder Fabry-Pérot etalon calibration system: evidence for chromatic variation
Ryan C Terrien, Joe P Ninan, Scott A Diddams +11
The comb-like spectrum of a white light-illuminated Fabry-Pérot etalon can serve as a cost-effective and stable reference for precise Doppler measurements. Understanding the stabil…
A Harsh Test of Far-Field Scrambling with the Habitable Zone Planet Finder and the Hobby Eberly Telescope
Shubham Kanodia, Samuel Halverson, Joe P. Ninan +18
The Habitable zone Planet Finder (HPF) is a fiber fed precise radial velocity spectrograph at the 10 m Hobby Eberly Telescope (HET). Due to its fixed altitude design, the HET pupil…
The Habitable-zone Planet Finder Detects a Terrestrial-mass Planet Candidate Closely Orbiting Gliese 1151: The Likely Source of Coherent Low-frequency Radio Emission from an Inactive Star
Suvrath Mahadevan, Guðmundur Stefánsson, Paul Robertson +17
The coherent low-frequency radio emission detected by LOFAR from Gliese 1151, a quiescent M4.5 dwarf star, has radio emission properties consistent with theoretical expectations of…
The Habitable-zone Planet Finder Reveals A High Mass and a Low Obliquity for the Young Neptune K2-25b
Gudmundur Stefansson, Suvrath Mahadevan, Marissa Maney +27
Using radial-velocity data from the Habitable-zone Planet Finder, we have measured the mass of the Neptune-sized planet K2-25b, as well as the obliquity of its M4.5-dwarf host star…
A warm Jupiter transiting an M dwarf: A TESS single transit event confirmed with the Habitable-zone Planet Finder
Caleb I. Cañas, Gudmundur Stefansson, Shubham Kanodia +30
We confirm the planetary nature of a warm Jupiter transiting the early M dwarf TOI-1899, using a combination of available TESS photometry; high-precision, near-infrared spectroscop…
TOI-1728b: The Habitable-zone Planet Finder confirms a warm super Neptune orbiting an M dwarf host
Shubham Kanodia, Caleb I. Canas, Gudmundur Stefansson +23
We confirm the planetary nature of TOI-1728b using a combination of ground-based photometry, near-infrared Doppler velocimetry and spectroscopy with the Habitable-zone Planet Finde…
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…
Persistent starspot signals on M dwarfs: multi-wavelength Doppler observations with the Habitable-zone Planet Finder and Keck/HIRES
Paul Robertson, Gudmundur Stefansson, Suvrath Mahadevan +23
Young, rapidly-rotating M dwarfs exhibit prominent starspots, which create quasiperiodic signals in their photometric and Doppler spectroscopic measurements. The periodic Doppler s…
A sub-Neptune sized planet transiting the M2.5-dwarf G 9-40: Validation with the Habitable-zone Planet Finder
Gudmundur Stefansson, Caleb Cañas, John Wisniewski +32
We validate the discovery of a 2 Earth radii sub-Neptune-size planet around the nearby high proper motion M2.5-dwarf G 9-40 (EPIC 212048748), using high-precision near-infrared (NI…
Evidence for He I 10830 Å~ absorption during the transit of a warm Neptune around the M-dwarf GJ 3470 with the Habitable-zone Planet Finder
Joe P. Ninan, Gudmundur Stefansson, Suvrath Mahadevan +21
Understanding the dynamics and kinematics of out-flowing atmospheres of hot and warm exoplanets is crucial to understanding the origins and evolutionary history of the exoplanets n…