Roman Surveys

Ranked as the highest scientific priority for a large space-based mission in the Astro2010 Decadal Survey, NASA’s Nancy Grace Roman Space Telescope will play a pivotal role in astrophysics in the 2020s and beyond. Roman will survey the sky 1,000 times faster than Hubble, collecting near-infrared imaging and spectroscopic data with Hubble-quality resolution and sensitivity over fields of view 200 times greater than Hubble’s WFC3/IR. Roman data will enrich all areas of astrophysics by enabling studies of nearly every class of astronomical object, phenomenon, and environment across the observable universe.

To enable these broad science goals, Roman's Wide-Field Instrument (WFI) observing program will include both Core Community Surveys (CCSs) and General Astrophysics Surveys (GAS). The majority of Roman’s five-year nominal mission will be devoted to the CCSs, which include a High Latitude Wide Area survey, a High Latitude Time Domain survey, and a Galactic Bulge Time Domain survey. A minimum of 25% of the five year nominal mission will be devoted to General Astrophysics Surveys. All data collected by Roman will be non-proprietary and available to all via the Mikulski Archive for Space Telescopes (MAST). The Roman mission will release mosaics, catalogs, and other data products, and will partner with the astronomical community to create open-source data reduction and analysis tools. Funding will be available through the General Investigator (GI) program for research using archival data. In addition, the Coronagraph Instrument observing program will be performed as part of the Technology Demonstration.

Roman Surveys will be defined by a combination of a community-led process and traditional peer-reviewed calls for proposals. The CCSs will be capable of meeting the Roman Mission’s cosmology and exoplanet science requirements while leaving significant parameter space available to establish the observational strategies (filters, depth, cadence, etc.) in a way that will enable a broad range of astrophysical investigations. All members of the science community can get involved in planning for Roman’s observing program prior to launch by participating in the definition of the CSSs through various calls for input, engaging deeply with specific topics via ongoing technical working groups, applying for funding for preparatory activities via ROSES, joining the Roman Science Collaboration, and proposing for observing programs or funding during Roman operations. The planning and preparation to enable and maximize the rich scientific return of Roman’s observing program has already begun, and will continue until, and after, Roman’s launch.

NASA's Engaging with Roman webpage provides an overview of the process for defining Roman’s surveys and the various ways to get involved with Roman.

High Latitude Wide Area Survey

The High Latitude Wide Area Survey aims to cover approximately 2,000 square degrees of the sky with imaging and low-resolution (grism) spectroscopy, for a total observing time of about two years. The preliminary survey design included an imaging component in four NIR bands (Y, J, H, and F184) with a depth of roughly J = 26.7 AB for point sources. The preliminary design also included a spectroscopy component to allow the measurement of redshifts for over 15 million sources at redshift 1.1 to 2.8. The preliminary design was optimized for studies of dark energy and cosmic lensing, but is now being optimized for studies across astrophysics, including high redshift galaxies and galactic halo substructure in nearby galaxies.

High Latitude Time Domain Survey

The three-tiered High Latitude Time Domain Survey includes both imaging and slitless spectroscopy, for a total observing time of approximately 0.6 years. The preliminary survey design included three tiers of imaging: shallow (~27 square degrees), medium (~9 square degrees), and deep (~5 square degrees). Observations would be repeated with a cadence of 5 days in filters Y/J-band for the shallow tier, and J/H-band for the medium and deep tiers. The survey was originally designed for detection and light-curve characterization of supernovae of redshifts up to 1.7, but is now being optimized to support a broad range of astrophysical research.

Galactic Bulge Time Domain Survey

The Galactic Bulge Time Domain Survey is intended to observe multiple fields in the Milky Way’s bulge for a total observing time of about one year. The preliminary survey design included high-cadence (every ~15 minutes) imaging of these fields over six contiguous 72-day seasons. This design is expected to create highly sampled light curves of 56 million stars brighter than H = 21.6 (AB). This sample is expected to yield the discovery of over 2000 bound planets in the range 0.1–1,000 Earth masses and orbital major axes from 0.03 to 30 AU through their microlensing signature. In addition, the survey is expected to enable the detection of about 20,000 giant planets in short-period orbits from their transit signature. The survey was originally conceived for a census of exoplanets and free-floating planets, but is now being optimized for a broader range of research, including studies of stellar populations in the Milky Way and structure of the Galaxy.

Coronagraph Instrument Program

A Coronagraph Instrument observing program will be performed as part of the Technology Demonstration. An associated Community Participation Program is already underway with the aim of working with the Coronagraph Instrument team to maximize the scientific and technical return of the observing program during the Technology Demonstration Phase. The preliminary program design is expected to paint a new picture for several dozen known planetary systems and disks. Some planets may be targeted for full spectral resolution observations to enable planet characterization.

General Astrophysics and Archival Research Programs

As Roman approaches launch and enters operations, additional opportunities to engage with the observatory will begin. Throughout Roman operations, there will be regular calls for Principal Investigator-led GASs, as well as for funded archival programs on both CCSs and GASs. Funded GI programs will use the wealth of data in Roman’s archive to perform all manner of astrophysical investigations, including addressing Roman’s cosmology and exoplanet demographic science goals. The selection of these programs will be made via a peer review process. The first of these calls is anticipated to be made approximately one year before Roman’s launch, after the definition of the CCSs is complete.

Additional Resources


Nancy Grace Roman Space Telescope insignia

The NASA Nancy Grace Roman Space Telescope is managed by NASA/GSFC with participation of STScI, Caltech/IPAC, and NASA/JPL.

Contact the Roman Team