Publications (64)
Searching for GEMS: TOI-5916 b & TOI-6158 b are two Saturn-density planets orbiting M2 dwarfs
Shane O'Brien, Amber Wong, Te Han +20
We confirm the planetary nature of (1) TOI-5916 b and (2) TOI-6158 b, two Exoplanets Transiting M-dwarf Stars (GEMS), both discovered by the Transiting Exoplanet Survey Satellite (…
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 ($M_p=0.70 \pm 0.03~\ma…
Utilizing Photometry from Multiple Sources to Mitigate Stellar Variability in Precise Radial Velocities: A Case Study of Kepler-21
Corey Beard, Paul Robertson, Mark R. Giovinazzi +26
We present a new analysis of Kepler-21, the brightest (V = 8.5) Kepler system with a known transiting exoplanet, Kepler-21 b. Kepler-21 b is a radius valley planet ($R = 1.6\pm 0.2…
Stellar and orbital characterization of three low mass M dwarf binary stars with dynamical spectroscopy from the Habitable Zone Planet Finder
Suhani Surana, Chad F. Bender, Caleb I. Cañas +13
Theoretical models of low-mass stars continue to be discrepant with observations when used to examine the mass-radius relationship and other physical parameters of individual stars…
Searching for GEMS: Two Super-Jupiters around M-dwarfs -- Signatures of Instability or Accretion?
Andrew Hotnisky, Shubham Kanodia, Jessica Libby-Roberts +20
We present the discovery of TOI-6303b and TOI-6330b, two massive transiting super-Jupiters orbiting a M0 and a M2 star respectively, as part of the Searching for GEMS survey. These…
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…
TOI-5344 b: A Saturn-like planet orbiting a super-Solar metallicity M0 dwarf
Te Han, Paul Robertson, Shubham Kanodia +19
We confirm the planetary nature of TOI-5344 b as a transiting giant exoplanet around an M0 dwarf star. TOI-5344 b was discovered with the Transiting Exoplanet Survey Satellite phot…
Target Prioritization and Observing Strategies for the NEID Earth Twin Survey
Arvind F. Gupta, Jason T. Wright, Paul Robertson +16
NEID is a high-resolution optical spectrograph on the WIYN 3.5-m telescope at Kitt Peak National Observatory and will soon join the new generation of extreme precision radial veloc…
The distant, galaxy cluster environment of the short GRB 161104A at and a comparison to the short GRB host population
Anya E. Nugent, Wen-fai Fong, Yuxin Dong +9
We present optical observations of the Swift short-duration gamma-ray burst (GRB) GRB 161104A and its host galaxy at . We model the multiband photometry and spec…
Searching for GEMS: The Occurrence of Giant Planets orbiting M-dwarfs within 100 pc
Rowen I. Glusman, Caleb I. Cañas, Shubham Kanodia +30
We present results from a systematic search for transiting short-period Giant Exoplanets around M-dwarf Stars (GEMS; days, ) within a distance-limi…
The IMACS Cluster Building Survey: V. Further Evidence for Starburst Recycling from Quantitative Galaxy Morphologies
Louis E. Abramson, Alan Dressler, Michael D. Gladders +5
Using and band imaging obtained as part of the IMACS Cluster Building Survey (ICBS) we measure Sérsic indices for 2160 field and cluster galaxies at . U…
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…
Extreme precision photometry from the ground with beam-shaping diffusers for K2, TESS and beyond
Gudmundur Stefansson, Suvrath Mahadevan, John Wisniewski +7
The Transiting Exoplanet Survey Satellite (TESS, launched early 2018) is expected to find a multitude of new transiting planet candidates around the nearest and brightest stars. Ti…
The NEID Earth Twin Survey. III. Survey Performance After Three Years on Sky
Arvind F. Gupta, Evan Fitzmaurice, Suvrath Mahadevan +22
The NEID Earth Twin Survey (NETS) has been delivering a rich set of precise radial velocity (RV) measurements for 41 bright, nearby main sequence stars. Here, we describe the statu…
Accretion Funnel Reconfiguration during an Outburst in a Young Stellar Object: EX Lupi
Koshvendra Singh, Joe P. Ninan, Marina M. Romanova +14
EX Lupi, a low-mass young stellar object, went into an accretion-driven outburst in March of 2022. The outburst caused a sudden phase change of ~ 112 5 in…
Time-resolved p-mode oscillations for subgiant HD 142091 with NEID at WIYN
Jacob K. Luhn, Paul Robertson, Samuel Halverson +22
Detections of Earth-analog planets in radial velocity observations are limited by stellar astrophysical variability occurring on a variety of timescales. Current state-of-the-art m…
A Versatile Technique to Enable sub-milli-Kelvin Instrument Stability for Precise Radial Velocity Measurements: Tests with the Habitable-zone Planet Finder
Gudmundur Stefansson, Frederick Hearty, Paul Robertson +13
Insufficient instrument thermo-mechanical stability is one of the many roadblocks for achieving 10cm/s Doppler radial velocity (RV) precision, the precision needed to detect Earth-…
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…
Searching for GEMS: Three warm Saturns and a super-Jupiter orbiting four early M-dwarfs
Pranav H. Premnath, Paul Robertson, Shubham Kanodia +33
The paper confirms and characterizes four short-period giant exoplanets—including three Saturn-mass planets and one dense super‑Jupiter—transiting early M‑dwarf stars, using TESS p…
Stable fiber-illumination for extremely precise radial velocities with NEID
Shubham Kanodia, Andrea S. J. Lin, Emily Lubar +24
NEID is a high-resolution red-optical precision radial velocity (RV) spectrograph recently commissioned at the WIYN 3.5 m telescope at Kitt Peak National Observatory, Arizona, USA.…
The NEID Earth Twin Survey. I. Confirmation of a 31-day planet orbiting HD 86728
Arvind F. Gupta, Jacob K. Luhn, Jason T. Wright +21
With close to three years of observations in hand, the NEID Earth Twin Survey (NETS) is starting to unearth new astrophysical signals for a curated sample of bright, radial velocit…
Origins of Super Jupiters: TOI-2145b Has a Moderately Eccentric and Nearly Aligned Orbit
Jiayin Dong, Ashley Chontos, George Zhou +15
Super Jupiters are giant planets with several Jupiter masses. It remains an open question whether these planets originate with such high masses or grow through collisions. Previous…
TOI-3984 A b and TOI-5293 A b: two temperate gas giants transiting mid-M dwarfs in wide binary systems
Caleb I. Cañas, Shubham Kanodia, Jessica Libby-Roberts +30
We confirm the planetary nature of two gas giants discovered by TESS to transit M dwarfs with stellar companions at wide separations. TOI-3984 A () is an M4 dwarf hosting…
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…
The FourStar Galaxy Evolution Survey (ZFOURGE): ultraviolet to far-infrared catalogs, medium-bandwidth photometric redshifts with improved accuracy, stellar masses, and confirmation of quiescent galaxies to z~3.5
Caroline M. S. Straatman, Lee R. Spitler, Ryan F. Quadri +26
The FourStar galaxy evolution survey (ZFOURGE) is a 45 night legacy program with the FourStar near-infrared camera on Magellan and one of the most sensitive surveys to date. ZFOURG…
Searching for GEMS: TOI-5349b is a Saturn-like planet orbiting a metal-rich early M-dwarf
Angeli Sandoval, Caleb I. Cañas, Shubham Kanodia +27
We report the confirmation and analysis of TOI-5349b, a transiting, warm, Saturn-like planet orbiting an early M-dwarf with a period of 3.3 days, which we confirmed as part o…
Observing the Sun as a star: Design and early results from the NEID solar feed
Andrea S. J. Lin, Andrew Monson, Suvrath Mahadevan +27
Efforts with extreme-precision radial velocity (EPRV) instruments to detect small-amplitude planets are largely limited, on many timescales, by the effects of stellar variability a…
TOI-5375 B: A Very Low Mass Star at the Hydrogen-Burning Limit Orbiting an Early M-type Star
Mika Lambert, Chad F. Bender, Shubham Kanodia +16
The TESS mission detected a companion orbiting TIC 71268730, categorized it as a planet candidate, and designated the system TOI-5375. Our follow-up analysis using radial velocity…
A comprehensive radial velocity error budget for next generation Doppler spectrometers
Samuel Halverson, Ryan Terrien, Suvrath Mahadevan +14
We describe a detailed radial velocity error budget for the NASA-NSF Extreme Precision Doppler Spectrometer instrument concept NEID (NN-explore Exoplanet Investigations with Dopple…
An eccentric Brown Dwarf eclipsing an M dwarf
Caleb I. Cañas, Suvrath Mahadevan, Chad F. Bender +16
We report the discovery of a brown dwarf transiting the early M dwarf TOI-2119 on an eccentric orbit () at an orbital period of $7.2008…
Stellar Spectroscopy in the Near-infrared with a Laser Frequency Comb
Andrew J. Metcalf, Tyler Anderson, Chad F. Bender +34
The discovery and characterization of exoplanets around nearby stars is driven by profound scientific questions about the uniqueness of Earth and our Solar System, and the conditio…
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…
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…
Ultra-Stable Environment Control for the NEID Spectrometer: Design and Performance Demonstration
Paul Robertson, Tyler Anderson, Gudmundur Stefansson +30
Two key areas of emphasis in contemporary experimental exoplanet science are the detailed characterization of transiting terrestrial planets, and the search for Earth analog planet…
A Candidate Transit Event around Proxima Centauri
Yiting Li, Gudmundur Stefansson, Paul Robertson +3
We present a single candidate transit event around Proxima Centauri, found during a blind transit search using a robotic 30\,cm telescope at Las Campanas Observatory. The event las…
Discovery of a Nearby Habitable Zone Super-Earth Candidate Amenable to Direct Imaging
Corey Beard, Paul Robertson, Jack Lubin +31
We present the discovery of GJ 251 c, a candidate super-Earth orbiting in the Habitable Zone (HZ) of its M dwarf host star. Using high-precision Habitable-zone Planet Finder (HPF)…
Searching for GEMS: Characterizing Six Giant Planets around Cool Dwarfs
Shubham Kanodia, Arvind F. Gupta, Caleb I. Canas +42
Transiting giant exoplanets around M-dwarf stars (GEMS) are rare, owing to the low-mass host stars. However, the all-sky coverage of TESS has enabled the detection of an increasing…
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…
Gaia24ccy: An outburst followed the footsteps of its predecessor
Koshvendra Singh, Joe P. Ninan, Zhen Guo +25
Accretion-driven outbursts in young stellar objects remain poorly understood, largely limited by a statistically small sample of closely followed-up events. This underscores the im…
Impact of crosshatch patterns in H2RGs on high precision radial velocity measurements: Exploration of measurement and mitigation paths with HPF
Joe P. Ninan, Suvrath Mahadevan, Gudmundur Stefansson +9
Teledyne's H2RG detector images suffer from cross-hatch like patterns which arises from sub-pixel quantum efficiency (QE) variation. In this paper we present our measurements of th…
TOI-2015b: A Warm Neptune with Transit Timing Variations Orbiting an Active mid M Dwarf
Sinclaire E. Jones, Gudmundur Stefansson, Kento Masuda +29
We report the discovery of a close-in () warm Neptune with clear transit timing variations (TTVs) orbiting the nearby ($d=47.3\:\mathrm{pc}…
An In-Depth Look at TOI-3884b: a Super-Neptune Transiting a M4 Dwarf with Persistent Star Spot Crossings
Jessica E. Libby-Roberts, Maria Schutte, Leslie Hebb +25
We perform an in-depth analysis of the recently validated TOI-3884 system, an M4 dwarf star with a transiting super-Neptune. Using high precision light curves obtained with the 3.5…
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…
TOI-4201: An Early M-dwarf Hosting a Massive Transiting Jupiter Stretching Theories of Core-Accretion
Megan Delamer, Shubham Kanodia, Caleb I. Cañas +24
We confirm TOI-4201 b as a transiting Jovian mass planet orbiting an early M dwarf discovered by the Transiting Exoplanet Survey Satellite. Using ground based photometry and precis…
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…
Searching for GEMS: Confirmation of TOI-5573b, a Cool, Saturn-like Planet Orbiting An M-dwarf
Rachel B Fernandes, Shubham Kanodia, Megan Delamer +35
We present the confirmation of TOI-5573b, a Saturn-sized exoplanet on an 8.79-day orbit around an early M-dwarf (3790 K, 0.59 R, 0.61 M, 12.30 J mag). TOI-5573b has a…
A "blue ring nebula" surrounding a thousands of years old stellar merger
Keri Hoadley, Christopher Martin, Brian D. Metzger +7
Stellar mergers are a brief-lived but common phase in the evolution of binary star systems. Among the many astrophysical implications of these events include the creation of atypic…
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…
Searching for GEMS: TOI-6383Ab, a giant planet transiting an M3-dwarf star in a binary system
Lia Marta Bernabò, Shubham Kanodia, Caleb I. Canas +22
We report on the discovery of a transiting giant planet around the 3500 K M3-dwarf star TOI-6383A located 172 pc from Earth. It was detected by the Transiting Exoplanet Survey Sate…
The Extreme Stellar-Signals Project III. Combining Solar Data from HARPS, HARPS-N, EXPRES, and NEID
Lily L. Zhao, Xavier Dumusque, Eric B. Ford +37
We present an analysis of Sun-as-a-star observations from four different high-resolution, stabilized spectrographs -- HARPS, HARPS-N, EXPRES, and NEID. With simultaneous observatio…
Solar Contamination in Extreme Precision Radial Velocity Measurements: Deleterious Effects and Prospects for Mitigation
Arpita Roy, Sam Halverson, Suvrath Mahadevan +19
Solar contamination, due to moonlight and atmospheric scattering of sunlight, can cause systematic errors in stellar radial velocity (RV) measurements that significantly detract fr…
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…
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 stabi…
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…
Return to the Great Attractor: Strong Evidence for a Steradian-sized Flow Converging at 70 Mpc within the GA Supercluster and Aligned with the CMB Dipole
Alan Dressler, Andrew Monson
We used the FourStar near-IR camera on Magellan-Baade to obtain high S/N H-Band imaging of 66 galaxies with radial velocities of 2000 < V < 5000 km/s. Our goal was to use the super…
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…
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…
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…
Evidence for He I 10830 Ã ~ 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…
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…
Calibration of the Tip of the Red Giant Branch (TRGB)
Wendy L. Freedman, Barry F. Madore, Taylor Hoyt +6
The Tip of the Red Giant (TRGB) method provides one of the most accurate and precise means of measuring the distances to nearby galaxies. Here we present a VIJHK absolute calibrati…
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…
UV to IR Luminosities and Dust Attenuation Determined from ~4000 K-Selected Galaxies at 1<z<3 in the ZFOURGE Survey
Ben Forrest, Kim-Vy H. Tran, Adam R. Tomczak +22
We build a set of composite galaxy SEDs by de-redshifting and scaling multi-wavelength photometry from galaxies in the ZFOURGE survey, covering the CDFS, COSMOS, and UDS fields. Fr…
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…