Roman Observations in the First Two Years of Science Operations
The Roman observing plan comprises three Core Community Surveys, coronagraph observations, a community-defined General Astrophysics Survey, and General Astrophysics Surveys selected through the Roman General Investigator (GI) program. In addition, some calibration observations are expected to yield scientifically valuable data.
Although the community-defined surveys are fully specified, the exact scheduling of observations is dependent on several factors. These include the start of Roman’s science operations, the selection of General Astrophysics Surveys, and target choices and timing within the coronagraph allocation. Nevertheless, much is already understood about the scheduling framework.
The Table of Observations in the First Two Years of Operations summarizes what is currently known about the observation plan, assuming a August 30, 2026 launch date and a 90-day commissioning period.
Scheduling to be Finalized
The detailed scheduling of Roman’s observations will depend on the start of science operations, the selection of General Astrophysics Surveys, and target choices and timing within the coronagraph allocation. This page will be updated as more information becomes available.
Table of Observations in the First Two Years of Operations
Survey component | Planned Window of Expected Observations (Subject to Change) | Likely Observations | Notes | ||
|---|---|---|---|---|---|
Core Community Surveys | Galactic Bulge Time Domain | High-cadence observations (3 seasons) | Feb 13 - Apr 25 2027* Aug 14 - Oct 30 2027 Feb 13 - Apr 25 2028 | *Duration tied to launch date; two days to be allocated to GPS observations per ROTAC recommendation. GBTDS observations will comprise the vast majority of observing time across the planned windows. | |
Low-cadence observations (1 season) | Aug 14 - Oct 30 2028 | GBTDS observations will make up only a fraction of the observing time in the planned windows, with the remainder allocated to other surveys (including GAS) and mission activities. | |||
High Latitude Time Domain | Pilot component (8 epochs) | Jan 7 - Feb 6 2027 (2 epochs, before 1st bulge season) April 25 - Aug 11 (6 epochs) | *Exact scheduling depends on launch date, General Astrophysics Surveys, and Coronagraph Instrument observations HLTDS observations will make up only a fraction of the observing time in the planned windows, with the remainder allocated to other surveys (including GAS) and mission activities. | ||
Extended component (3 epochs) | Oct 27 - Nov 17 2027 Jan 20 - Feb 10 2028 Apr 25 - May 8 2028 | ||||
Core component | 5 days cadence starting between Jun 5 to Jun 19 2028 | ||||
High Latitude Wide Area | Deep Tier | Completed by Feb. 10 2028 | *Exact scheduling depends on launch date, General Astrophysics Surveys, and Coronagraph Instrument observations. "Partial observations" indicates that only a fraction of the observations will be taken during the first two years for both the imaging and spectroscopic modes. HLWAS observations will make up only a fraction of the observing time in the planned windows, with the remainder allocated to other surveys (including GAS) and mission activities. | ||
Ultra Deep Tier - Half depth | May-Jun. 2028 | ||||
Medium Tier - field 1** | Partial Observations - Imaging & Spectroscopy | ||||
Medium Tier - field 2** | Partial Observations - Imaging & Spectroscopy | ||||
Wide Tier | Partial Observations | ||||
General Astrophysics Surveys | Galactic Plane Survey | Wide Field | 1st epoch: Apr - Nov 2027 2nd epoch: Jun - Nov 2028 | Exact scheduling depends on launch date, General Astrophysics Surveys, and Coronagraph Instrument observations GPS observations will make up only a fraction of the observing time in the planned windows, with the remainder allocated to other surveys (including GAS) and mission activities. | |
Deep fields | Fully observed in 2028 | ||||
Time Domain | Fully observed in 2028 | ||||
Calibration Touchstone Fields | Astro-Photometry | Long observations Astrometric solution & flatfield | Once per year | Final cadence determined after on-orbit instrument characterization | |
Short observations Stability | Quarterly | ||||
Spectroscopy | Monthly | ||||
Coronagraph Instrument Observations | Wide Field Instrument Parallel Observations | TBD | TBD | ||
** Refer to the HLWAS Outline of Medium and Wide Tiers for the location of the two Medium tier fields
Additional Resources
To explore the community-defined surveys and their scientific capabilities in more detail, please see Additional Resources for Community-defined Surveys.
For additional questions not answered in this article, please contact the Roman Help Desk.