Welcome to the GSFC Exoplanet Modeling and Analysis Center (EMAC)
EMAC serves as a catalog, repository and integration platform for modeling and analysis resources focused on the study of exoplanet characteristics and environments. EMAC is a key project of the GSFC Sellers Exoplanet Environments Collaboration (SEEC).
If you've used EMAC in any part of your research, please cite our RNAAS paper either in your methods section or in the "Software used" portion of any manuscripts; see the FAQ for more information.
More Information on EMAC for first-time visitors...If you make use of tools linked or hosted on EMAC: please use the following statement in your publication acknowledgements: โThis research made use of the NASA Exoplanet Modeling and Analysis Center (EMAC), which is funded by the NASA Planetary Science Division's Internal Scientist Funding Model.โ
Stay up to date with EMAC!- Subscribe to our monthly RSS messages on new updates and tools.
- Check out the Bluesky account @exoplanetmodels.bsky.social (not an official NASA account), where new tools and features are highlighted.
- Email us with general feedback at and tell us what you'd change or improve.
- Click the
icon in a resource box to provide suggestions for an individual tool or tools.
- EMAC is intended as a clearinghouse for the whole research community interested in exoplanets, where any software or model developer can submit their tool/model or their model output as a contribution for others to use.
- EMAC provides a searchable and sortable database for available source code and data output files - both resources hosted locally by EMAC as well as existing external tools and repositories hosted elsewhere.
- The EMAC team also helps develop new web interfaces for tools that can be run โon-demandโ or model grids that can be interpolated for more individualized results.
- If you would like to submit a new tool/model to EMAC, please visit our Submit a Resource page.
- For help with tutorials for select resources/tools use the โDemoโ buttons below and subscribe to our YouTube channel.
- Watch this video for a walk-through of the whole EMAC site, including how to submit a new tool and how to access information for each resource.
EMAC co-leads are Joe P. Renaud and Eric Lopez; more information on EMAC staffing and organization can be found on Our Team page.
EMAC has launched a new community-supported curator program, and we need your help! Check out our curator page to learn how exoplanet experts like yourself can support EMAC's mission, and help us spread the word about this new initiative!
The JWST Collection
Collection of tools related to data reduction, analysis, and model fitting specifically for JWST exoplanet-related data
eclipsoid: Open-source JAX-based Python package
Dholakia, Shashank; Dholakia, Shishir; Pope, Benjamin J. S.
Eclipsoid provides a general framework allowing rotational deformation to be modeled in transits, occultations, phase curves, transmission spectra and more of bodies in orbit around each other, such as an exoplanet orbiting a host star.
ExoLyn: a golden mean approach to multi-species cloud modelling in atmospheric retrieval
Huang, Helong; Ormel, Chris W.; Min, Michiel
ExoLyn is a 1D cloud model that balances physical consistency with computational efficiency. ExoLyn solves the transport equation of cloud particles and vapor under cloud condensation rates that are self-consistently calculated from thermodynamics. ExoLyn is a standalone, open source package capable to be combined with optool to calculate solid opacities and with petitRADTRANS to generate transmission or emission spectra. The efficiency of ExoLyn opens the possibility of joint retrieval of exoplanets' gas and cloud components. ExoLyn has been designed to study cloud formation across a variety of planets: hot Jupiters, sub- Neptunes, and self-luminous planets.
OrCAS: Origins, Compositions, and Atmospheres of Sub-neptunes
Crossfield, Ian J. M.; Polanski, Alex S.; Robertson, Paul; et al.
OrCAS is a survey to better elucidate the origins, compositions, and atmospheres of sub-Neptunes. This radial velocity survey uses a repeatable, quantifiable metric to select targets suitable for subsequent transmission spectroscopy and address key science themes about the atmospheric & internal compositions and architectures of these systems. Our survey targets 26 systems with transiting sub-Neptune planet candidates, with the overarching goal of increasing the sample of such planets suitable for subsequent atmospheric characterization.
GASTLI: GAS gianT modeL for Interiors
Acuรฑa, Lorena; Kreidberg, Laura; Zhai, Meng et al.
GASTLI (GAS gianT modeL for Interiors) calculates the interior structure models for volatile-rich exoplanets with H/He and water envelopes. The code computes mass-radius curves, thermal evolution curves, and interior composition retrievals to fit a interior structure model to your mass, radius, age, and if available, atmospheric metallicity data. GASTLI can also plot the results, including internal and atmospheric profiles, a pressure-temperature diagram, mass-radius relations, and thermal evolution curves.
ExoJAX: Differentiable Spectrum Modeling of Exoplanets/Brown Dwarfs using JAX
Kawahara, Hajime; Kawashima, Yui; The ExoJAX team et al.
ExoJAX is designed to directly calculate cross-sections as functions of temperature and pressure, rather than interpolating tabulated data, to minimize errors in high-dispersion spectra modeling. Has developed differentiable radiative transfer schemes, including emission, transmission, and reflection spectroscopy. These enhancements significantly expand the range of applications.
speclib: Tools for interfacing with stellar spectral libraries.
Rackham, Benjamin V.
speclib is a Python package for working with grids of model stellar spectra. It can download PHOENIX spectra (Husser et al. 2013) on the fly and can also work with pre-downloaded libraries of MPS-Atlas (Witzke et al. 2021, Kostogryz et al. 2023) and SPHINX (Iyer et al. 2023) spectra.
Gen TSO: A graphical interface to simulate JWST time-series observations of exoplanets
Cubillos, P. E.
Gen TSO enables the estimation of signal-to-noise ratios for transit/eclipse depths through an interactive graphical interface, similar to the JWST Exposure Time Calculator (ETC). This interface leverages the ETC by combining its noise simulator, Pandeia, with additional exoplanet resources from the NASA Exoplanet Archive, the Gaia DR3 catalog, and the TrExoLiSTS database of JWST programs. Gen TSO allows users to calculate S/Ns for all JWST instruments for the spectroscopic time-series modes available as of the Cycle 4 GO call. It also allows users to simulate target acquisition on the science targets or, when needed, on nearby stellar targets.
NEMESISPY: A Python package for simulating and retrieving exoplanetary spectra
Yang, Jingxuan ; Alday, Juan ; Irwin, Patrick
NEMESISPY is a Python package developed for atmospheric retrievals, which is the inference of atmospheric properties such as chemical composition using spectroscopic data. The package contains code for radiative transfer calculation using the correlated-k approximation and for parametric atmospheric modelling. NEMESISPY is a recent and active development of the well-established Fortran NEMESIS library (Irwin et al., 2008), which has been applied to the atmospheric retrievals of both solar system planets and exoplanets employing numerous different observing geometries.
exoTEDRF: exoplanet Transit and Eclipse Data Reduction Framework
Radica, Michael
Formerly known as supreme-SPOON, exoTEDRF is an end-to-end pipeline for the reduction of JWST exoplanet time series observations (NIRISS and NIRSpec currently supported, MIRI in development).
APPleSOSS: A Producer of ProfiLEs for SOSS. Application to the NIRISS SOSS Mode
Radica, M. et al.
A tool to produce empirical 2D point spread functions for JWST NIRISS/SOSS observations. These PSFs are necessary input for the ATOCA extraction algorithm implemented in the STScI calibration pipeline.
luas: A 2D Gaussian process package for systematics correlated in two dimensions
Fortune, Mark et al.
luas (from the Irish word for speed) is a small library aimed at building Gaussian processes (GPs) primarily for two-dimensional data sets. This has particularly useful applications when it comes to joint-fitting spectroscopic transit light curves, as demonstrated in Fortune et al. (2024). By utilising different optimisations - such as using Kronecker product algebra - we can make the application of GPs to 2D data sets which may have dimensions of 100s-1000s along both dimensions possible within a reasonable timeframe. luas can be used with popular inference frameworks such as NumPyro and PyMC for which there are tutorials to help you get โstarted.
PHOTOe: An efficient Monte Carlo model for the slowing down of photoelectrons
Monte Carlo model for simulating the slowing down of photoelectrons in gases in the local deposition approximation.
Version v1 works with H and He atoms plus thermal electrons. The model is described in:
Garcรญa Muรฑoz, Icarus, Volume 392, 1 March 2023, 115373
The model is available at https://antoniogarciamunoz.wordpress.com/ and upon email request from the author.
spaceKLIP: Pipeline for reducing & analyzing JWST coronagraphy data with the help of pyKLIP
JWST ERS 1386 Team
The spaceKLIP pipeline enables to reduce & analyze JWST NIRCam & MIRI coronagraphy data. It provides functions to run the official jwst stage 1 and 2 data reduction pipelines with several modifications that were made to improve the quality of high-contrast imaging reductions. It then performs PSF subtraction based on the KLIP algorithm as implemented in the widely used pyKLIP package, outputs contrast curves, and enables forward model PSF fitting for any detected companions in order to extract their properties (offset and flux). The pipeline is still under heavy development.
JET: JWST Exoplanet Targeting Program
Fortenbach, Charles; Dressing, Courtney et al.
JWST will devote significant observing time to the study of exoplanets. It will not be serviceable as was the Hubble, and therefore the spacecraft/instruments will have a relatively limited life. It is important to get as much science as possible out of this limited observing time. We provide a computer tool, JET, to optimize lists of exoplanet targets for atmospheric characterization. JET takes catalogs of planet detections; categorizes the targets by radius and equilibrium temp.; estimates planet masses; generates model spectra and simulated instrument spectra; performs a statistical analysis to confirm an atmospheric detection; and finally, ranks the targets by observation time required.
Planetary Spectrum Generator: An Online Tool for Synthesizing Planetary Spectra
Villanueva, Geronimo et al.
The Planetary Spectrum Generator (PSG) is an online tool for synthesizing planetary spectra (atmospheres and surfaces) for a broad range of wavelengths (100 nm to 100 mm, UV/Vis/near-IR/IR/far-IR/THz/sub-mm/Radio) from any observatory (e.g., JWST, ALMA, Keck, SOFIA).
PandExo: JWST/HST Simulator
Batalha et al.
PandExo is both an online tool and a Python package for generating instrument simulations of JWST's NIRSpec, NIRCam, NIRISS and NIRCam and HST WFC3. It uses throughput calculations from STScI's Exposure Time Calculator, Pandeia.
petitRADTRANS: Tool for Calculating Transmission and Emission Spectra of Exoplanets with Clear and Cloudy Atm.
Molliรจre, Paul
PetitRADTRANS (pRT) is a Python package for calculating transmission and emission spectra of exoplanets, at low (๐/ฮ๐=1000) and high (๐/ฮ๐= $10^6$) resolution, for clear and cloudy atmospheres. pRT offers a large variety of atomic and molecular gas opacities, cloud cross-sections from optical constants, or parametrized cloud models using either opacity power laws or grey cloud decks. The code also calculation of emission and transmission contribution functions, and contains a PHOENIX/ATLAS9 spectral library for host stars to calculate planet-to-star contrasts. Implemented examples for MCMC retrievals with pRT can be found on the code website.
