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Late Breaking News

Changes since the Cycle 24 Call for Proposals has been Frozen

April 06, 2016

Discrepancy with JWST Preparatory Proposals and Default Diagnostic APT Message

We just realized that there is an implementation error in APT for this flag. Please set the proprietary period however you wish for your proposal. The Call for Proposals is correct, the default is 0, which was implemented, just the Diagnostic message that appears is incorrect and the TAC/Panels will be informed to ignore those messages for those proposals.

March 15, 2016

Discrepancy on Page 63 of Cycle 24 Call For Proposals has been updated

We just realized that on page 63 Section 7.1.3 Page Limits for PDF Attachment, that there is a discrepancy between bullets 2 and 3 in the section "In relation to these page limits, note the following:". The word references should be removed from Bullet 2 as the current new revised policy for references is now covered in Bullet 3 "References should be listed at the end of the proposal and do not count against the page limits". A new version of the Cycle 24 Call for Proposals was replaced on our website on 3/15/16 to fix this issue.

March 03, 2016

LINEAR: A Grism Simulation Code for WFC3/IR

LINEAR is a package of IDL and C routines developed to predict noiseless grism imaging from an existing direct image and pointing description. LINEAR is also capable of predicting contamination (the fraction of flux coming from other sources) as a function of wavelength. Possible future developments of LINEAR will be designed to extract non-parametric spectrum consistent with the available dispersed data, which may be taken at various positions and/or orientations. See the WFC3-grism webpage for more information.

February 26, 2016

A new technique for wide-field near-IR imaging with WFC3

A new observing strategy has been developed to allow for wide shallow observations using the WFC3/IR camera on the Hubble Space Telescope. The length of a guide star acquisition by HST limits observations to no more than two pointings per orbit. This limitation can be circumvented by guiding with gyros alone, which is possible as long as the telescope has three functional gyros. Since HST drifts only by ∼ 1/4 WFC3/IR pixel in the 25 seconds between consecutive, non-destructive reads of unguided exposures, the individual reads can be shifted relative to one another and co-added, restoring the full resolution of WFC3. We have used this tiling technique to observe four orbits (32 pointings) of a pilot survey program (GO-14114, PI: van Dokkum). Both the telescope behavior and the data quality are within the expected range, confirming that this is a viable technique. By following the observing strategy of GO-14114, programs can cover 1 square degree in 100 orbits to a depth of H(F160W) = 25.0. While this is the most efficient observing strategy, other variations are possible, depending on the scientific goals of the program. This new observing technique is now available as part of the Cycle 24 call for proposals.

A more detailed description of this technique can be found in this document. This new observing technique is now available as part of the Cycle 24 call for proposals.

The webpage is now available. A full length paper on this method is also now available. Questions about it should be addressed to

February 09, 2016

APT 24.0 Has been Released.

APT 24.0 has been released for use for Cycle 24 Proposals.

Release Documents

    The Call for Proposals describes the policies and procedures for submitting a HST Phase I proposal. Get the CP as: PDF [US Letter Size], PDF [A4 Size], or as HTML.

    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 24 HST Phase I

  • Full Set of HST Documentation

HST Phase I Roadmap

    The Roadmap is a step-by-step guide to proposing and submitting an HST proposal. Download APT here.

DD Time

Up to 10% of the available HST observing time may be reserved for Director's Discretionary (DD) allocation.

Mid-Cycle Proposals

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:

Past Proposal Opportunities