Shubham Kanodia
I am a Carnegie Postdoctoral Fellow at Carnegie's Earth & Planets Laboratory in Washington DC, where astronomers work alongside geochemists, geophysicists, and cosmochemists. My research asks: how do giant exoplanet properties depend on the mass of the host star, and the system ice line? A lot of this is focussed towards the discovery, characterization and formation of Giant Exoplanets around M-dwarf Stars (GEMS), an extreme regime of planet formation that has traditionally been hard to explain. To answer it, I combine instrumentation, statistics, observations and modelling, from precise radial velocity spectrographs to JWST, Ariel and Gaia, and draw on detailed studies of the Solar System's giant planets to inform and verify our models of planetary interiors.
Before moving to Carnegie, I was a graduate student at Penn State Department of Astronomy & Astrophysics, where I worked on exoplanet instrumentation and statistics, with my advisor Suvrath Mahadevan. My research focussed on developing the tools to detect exoplanets, and characterise their populations, particularly those orbiting these cool and low mass stars.
I helped develop and deploy two highly precise radial velocity (RV) spectrographs - the near-infrared Habitable zone Planet Finder (HPF) and the optical NEID spectrograph. HPF, deployed at the 10 m Hobby Eberly Telescope in Texas, USA, is a near-infrared RV spectrograph built to find planets around mid-late M-dwarfs. NEID is a product of the NASA-NSF collaboration, and is a new generation optical spectrograph built for the 3.5 m WIYN telescope in Arizona.
In addition, I have worked to develop new astro-statistical tools to characterize exoplanet populations using novel non-parametric techniques. I have used these to compare planet populations around M-dwarf and solar-type stars, and to design the Searching for GEMS survey.
Ongoing Projects
Searching for Giant Exoplanets around M-dwarf Stars (GEMS)
Detection & Characterization
I am leading the Searching for GEMS survey of a million M dwarfs within 200 pc, where we are using a combination of photometric, spectroscopic and high-contrast imaging observations to detect and characterize transiting GEMS. The survey has discovered more than half of all known transiting GEMS, and my students are using it to measure how often such planets occur. Comparing the bulk properties of these planets with protoplanetary disk samples, I suggested that a minimum disk mass is required to form giant planets through core accretion. I have also explored the formation of GEMS across a range of protostellar M-dwarfs using gravitational instability models.
Atmospheric Characterization
I am the PI of GEMS JWST (GO 3171), the largest exoplanet program in JWST Cycle 2, along with co-PIs Caleb Cañas and Jessica Libby-Roberts, and an amazing group of collaborators. We have obtained 18 transits of seven GEMS, and find that their atmospheres are far more metal-poor than those of giant planets around solar-type stars, even though their bulk compositions are metal-rich. My JWST Cycle 4 program will test these results with secondary eclipses (emission spectroscopy).
Preparing for Ariel
I am the Science PI of a NASA-funded project to prepare for ESA's upcoming Ariel mission, which will extend these findings to a much larger sample of planets. With Ravit Helled and collaborators, we have examined how Ariel can help measure the metallicities of giant planets around low-mass stars (Helled, Shibata, Kanodia et al. 2026).
Finding cold GEMS with Gaia astrometry
Gaia's fourth data release (DR4; December 2026) is expected to add thousands of astrometrically detected planets, including hundreds of GEMS on wider orbits. I developed pyGaiafits to jointly fit Gaia epoch astrometry with radial velocities, and applied it to the DR4 pre-release to improve the estimates for Gaia-4b, the first planet from Gaia astrometry to be confirmed from the ground, with RVs from HPF and NEID. I am now initiating a survey of 30,000 M dwarfs observed by Gaia to find cold GEMS that span the M-dwarf ice line.
Comet delivery to rocky planets
Giant planets can influence whether water-rich comets from the outer system reach the inner, rocky planets. With John Chambers, I have worked on a Markov-chain model of cometary orbital evolution that computes collision, ejection and escape probabilities without N-body integrations, and we find that comet delivery in compact planetary systems is independent of stellar mass (Chambers & Kanodia, submitted).
Characterizing sub-Jovian planets orbiting M-dwarfs
I am currently part of a team that is following up on TESS planet candidates orbiting M-dwarfs to obtain precise mass measurements. It is imperative to obtain these precise mass measurements to find suitable targets for transmission spectroscopy missions such as the James Webb Space Telescope, as well as to populate the Mass-Radius plane for M-dwarf host exoplanets. We do this using a combination of precise radial velocity measurements using HPF and NEID, and diffuser-assisted photometry.
Developing Precision RV spectrographs
Habitable-zone Planet Finder (HPF)
HPF is a near-infrared precision RV spectrograph deployed at the 10-m Hobby-Eberly Telescope in Texas, USA. I have been a key member of the instrument and science teams for the instrument, and led the fabrication, testing, and commissioning of the fiber injection system for HPF. I also performed the optical simulations to facilitate the optical alignment of the instrument during the alignment, integration and verification phase at Penn State.
NEID
NEID -the cornerstone of the NASA-NSF NN-EXPLORE partnership- is an optical RV spectrograph spanning 380 to 930 nm. Built to achieve an instrument precision of 30 cm/s, it is designed to find Earth-like planets in the habitable zones around FGK stars. As a part of the NEID instrument and science team, I was responsible for the development, fabrication and testing of the NEID fiber injection system which includes the instrument fiber, scrambling system, as well as the fibers associated with the calibration system. In addition, I was in charge of the design, testing and deployment of the NEID exposure meter system to provide chromatic barycentric corrections at the 1 cm/s level. I was also a part of the commissioning team for the instrument in 2019-2020, and regularly use its precision capabilities towards forwarding our science goals.
Non-parametric statistical tools to study planetary population
I have helped develop novel non-parametric tools to study the Mass-Radius relationship for exoplanets orbiting M-dwarf host stars, and then compared this relationship for analogous planets around FGK stars. Since then I have helped extend this framework to multiple dimensions and allow the simultaneous unbiased modelling of up to four dimensions to study the interplay between stellar properties such as mass, metallicity, age and planetary population parameters (mass, radius, period).
NIR stellar spectroscopy
I worked on a project to characterize a high energy stellar flare around faint M8 star - vB10 using HPF spectra. We find the first evidence of coronal rain around such a low mass star using our observations of the Helium triplet. These high resolution near-infrared observations of a stellar flare present a valuable opportunity to study flare properties for very low mass stars in a hitherto unexplored regime. Read more about it on the HPF blog.
Interests
- M-dwarfs
- Giant Planets
- Planet Formation
- Giant Planet Interiors
- Astrometry
- Atmospheric Characterization
- Astrostatistics
- Instrumentation
- Fiber Optics
- Optical Simulation
- SETI
Open-Source tools
I have helped develop a few Python packages that are open source and available to the community.
- pyGaiafits - Fits Gaia epoch astrometry with a single-star or binary orbit model, optionally jointly with radial velocities (Kanodia et al., submitted).
- exoComet - A 1D Markov-chain model for comet delivery in compact planetary systems, giving collision, ejection and escape probabilities without N-body integration (Chambers and Kanodia, submitted).
- pyastrotools - Library of helper functions for astronomical calculations, observation planning, instrumentation, etc.
- Barycorrpy - Adapted from Wright and Eastman (2014), this package provides a simple routine to compute barycentric corrections for stellar radial velocity observations at the 1 cm/s level (Kanodia and Wright 2018). In addition, it also includes tools to compute barycentric corrections for observations of solar system objects (Wright and Kanodia 2020).
- MRExo - This package allows the user to fit a Mass-Radius relation on any 2 dimensional dataset using nonparametric methods (Kanodia et al. 2019). In addition, it can be used to predict mass from radius (and vice versa) based on a M-dwarf or FGK host star sample, which was subsequently expanded to include additional dimensions and allow for sample inference.
Mentoring, Education & Outreach
I have supervised 12 undergraduate and two master's students and co-advised seven PhD students, from a community-college student to PhD students at research institutes in Germany and India. Together they have led nine first-author papers (2024–2026) on new discoveries, giant-planet formation, and demographics. I also developed and taught an informal course at Penn State on astronomical computing and probabilistic programming.
In 2025, I worked with the U.S. National Park Service to revamp the astronomy exhibits at the Rock Creek Park Nature Center and Planetarium in Washington, DC, updating them with recent discoveries and making them accessible to visually impaired visitors. I have also volunteered with the Carnegie Academy for Science Education's First Light program, Penn State's Astrofest, Brown's Saturday STEM program, and the Umang Foundation in Mumbai, and have given public talks at the Nehru Planetarium, Astronomy on Tap, and the National Capital Astronomers. More details are in my CV.