Roman Observations in the First Two Years of Science Operations
The Roman observing plan comprises three Core Community Surveys; coronagraph observations; community-defined General Astrophysics Surveys; 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 has yet to be finalized. Timing depends on several factors, including 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 September 28, 2026 launch date and a 90-day commissioning period.
Scheduling to be Finalized
The detailed scheduling of Roman’s observations will be determined by 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 | Likely Observations | Notes | ||
|---|---|---|---|---|---|
Core Community Surveys | Galactic Bulge Time Domain | High cadence seasons | Feb 11 - Apr 20 2027* Aug 15 - Oct 25 2027 Feb 11 - Apr 21 2028 | *Duration tied to launch date; final two days for GPS observations (ROTAC). Observations will comprise the vast majority of observing time across the planned windows. | |
Low cadence season | Aug 16 - Oct 24 2028 | 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 Eight epochs | Apr 22 - Aug 14 2027 or Oct 26 2027 - Feb 10 2028 | Exact scheduling depends on launch date, General Astrophysics Surveys, and Coronagraph Instrument observations 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 Three epochs | 2 epochs: Oct 26 2027 - Feb 10 2028 1 epoch: Apr 22 - Jun 4 2028 | ||||
Core component | 5 days cadence starting on Jun 5 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 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 First pass, half depth | Apr - Jun 2028 | ||||
Medium tier - field 1** | Completed by end of 2028* | ||||
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 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.