Cycle 25 Announcement
STScI solicits proposals for HST Observing, Archival & Theoretical Research. Full details are made available through two documents, the Call for Proposals and the HST Primer.
January 13, 2017
Cycle 25 Call for Proposals
Late January 2017
APT Cycle 25 Phase I Release
April 07, 2017
Cycle 25 Phase I Proposal Deadline
June 11, 2016
Cycle 25 Peer Review
June 30, 2017
Cycle 25 Phase I Notifications
July 20, 2017
HST Cycle 25Phase II Proposal Deadline
Call for Proposals
The Call for Proposals (CP) invites the astronomical community to propose for observing time on HST in a given cycle (nominally one year in duration). It summarizes the policies and procedures for proposing in that cycle of HST observing, including requests for funding research on archival HST data. It also provides an overview of HST's expected capabilities for that observing cycle, including information about the telescope and the available scientific instruments.
For more information on the current proposing cycle see the Cycle 25 Announcement Page.
Phase I: Writing and Submitting a Proposal for HST Observing Time
A Phase I proposal provides:
- A summary of the observing program.
- The scientific justifications for the program.
- A list of targets with their celestial coordinates.
- The instrument(s) to be used with desired modes, filters, and dispersers.
- An estimate of the number of spacecraft orbits needed to accomplish the observing program (a means to calculate this number is provided in the Phase I instructions).
Proposers should consult all relevant technical documentation about the capabilities and sensitivities of the instrument(s) to be used in their programs and should discuss the requirements of their observing programs with appropriate STScI experts. Contacts are provided via the STScI HelpDesk at email@example.com. To avoid duplication conflicts proposers also should consult up-to-date exposure catalogs, available on-line at the STScI Web site.
Completion of Phase I: The TAC Review of Phase I Submissions
A Telescope Allocation Committee (TAC), organized by the Space Telescope Science Institute (STScI), reviews and evaluates the submitted Phase I proposals. The TAC recommends a list of programs to the STScI Director for preliminary approval and implementation. Upon final approval by the Director, a successful proposal enters into the Phase II stage of proposal preparation.
Phase II: Providing the Observing Details
Following a favorable TAC review and approval by the director, proposers must provide the details required by the ground system to schedule HST and obtain their observations.
Observers are assigned two points of contact at STScI: a Program Coordinator (PC) and a Contact Scientist (CS). The PC helps the observer to deliver a Phase II proposal which is syntactically correct and will schedule successfully on the telescope. The CS provides advice on observing strategies to meet the scientific objectives of the program, answers questions about instrument performance, and can provide technical help in the data analysis phase of the observing program. The CS is an Instrument Scientist involved in the calibration and characterization of the primary instrument used in the observer's program.
Programs are not considered fully accepted until the following items have been completed:
- An error-free Phase II proposal has been submitted.
- Duplication checks against similar exposures in previous and current HST programs have been performed and any conflicts have been resolved.
- All technical feasibility reviews (such as bright object checking, special requirements, etc.) have been completed and approved.
- Full Set of HST Documentation
The Primer provides an introductory overview of the Hubble Space Telescope and explains how to calculate the appropriate number of orbits for an observing proposal. Get the Primer as: PDF [US Letter Size], PDF [A4 Size], or as HTML.
Science Justification Templates for Cycle 25 HST Phase I
HST Phase I Roadmap
Up to 10% of the available HST observing time may be reserved for Director's Discretionary (DD) allocation.
Up to 200 orbits per cycle will be available for Mid-Cycle GO programs. Mid-Cycle programs were initiated in Cycle 23 to provide the community with an opportunity to propose for in-cycle observations of recently-discovered, non-variable objects. As such, they complement Director’s Discretionary programs, which target unexpected transient phenomena and time-critical observations..
Special Programs from Past Cycles
Status of Current and Past Programs:
- Treasury, Archival Legacy and Large
- JWST Preparatory
- UV Initiative
- Joint Observatory
- Joint XMM-HST Proposals