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HST @ STScI Update

Rachel Osten (osten[at]stsci.edu)


This newsletter article summarizes some of the recent activities undertaken by STScI to keep the astronomy community informed about Hubble's performance and to involve the community in Hubble's long-term planning.  A new feature at AAS meetings now includes STScI Town Halls, of which Hubble activities are one component. A special session at the upcoming winter AAS meeting will include presentations and discussions about how the telescope can remain relevant and at the forefront of astronomy into the next decade. Hubble observing opportunities now include several special initiatives; the article describes these and the reasoning behind them.  The article finishes with a delineation of a new strategic initiative using Director’s Discretionary time to maximize Hubble's UV legacy.

STScI Town Halls at AAS Meetings

The very first STScI Town Hall took place during the 232nd meeting of the American Astronomical Society in Denver this past June, as a venue for informing the community about the science operations and other strategic activities in which the Institute is leading efforts. The agenda started with a welcome and opening by the director, Ken Sembach, followed by descriptions of innovations in data science at STScI; open development of community software for astronomical data analysis; new capabilities and opportunities for Hubble in the next decade; and WFIRST science and the AAS community. The Town Hall was well attended, and a lively discussion followed the presentations.

With the approval of another STScI Town Hall at the upcoming 233rd winter AAS meeting, the Institute aims to make this a regular feature of AAS meetings. The format for the winter Town Hall will start with a few general talks on the work done at STScI, followed by a more focused block of quick talks on our involvement in planetary science. This will include Hubble research highlights in planetary science, upcoming solar system and exoplanet campaigns, and descriptions of new tools and archive abilities relevant to planetary scientists.


Hubble and its instruments are healthy, and projections for its lifetime indicate that it will be operating well into the next decade. New tools and observing modes refresh and extend Hubble’s science grasp, even nine years after the last servicing mission (see the article on recent advances in tools and observing modes in this Newsletter). Hubble’s science portfolio is driven by community requests for the telescope’s unique capabilities, evolving instrument modes, and rich archive.  Given this perspective, are there changes for Hubble that will enable it to remain at the forefront of the changing astronomical landscape foreseen in the next decade? A special session at the upcoming winter AAS meeting in Seattle, WA will highlight new results coming out of the observatory in some of the forefront science areas in which Hubble has excelled, and will start a dialogue between its science operations center and the scientific community about the role Hubble should play in the science of the 2020s.  The session, “A Hubble Space Telescope for the 2020s: Capabilities and Opportunities,” is currently scheduled for January 10, 10:00–11:30 a.m.

Special Initiatives for Observing Programs

STScI utilizes special initiatives in order to focus the proposal selection to achieve high level strategic goals making use of Hubble’s unique capabilities. These are always based on community input from working groups and are endorsed by the Space Telescope Users’ Committee. For instance, the UV Initiative, in place since Cycle 21, encourages submissions in nearly all categories of proposals which seek to utilize Hubble’s particular capability in accessing the ultraviolet (UV) portion of the electromagnetic spectrum. Telescope Allocation Committees (TACs) have been encouraged to devote at least 40% of their orbit allocation to UV-specific science; these levels are advisory, not quotas, and all accepted Hubble proposals must meet the high bar of outstanding scientific quality. Starting in Cycle 24, a Webb Preparatory Program has existed to enable science observing programs anticipated for Webb that can be enhanced or expanded through the inclusion of Hubble time prior to the Webb observations. Proposals in this category are evaluated on the science case of both the Hubble and anticipated Webb observations. A special call for proposals to learn more about Europa and its plumes took place in Cycle 25. This followed the recommendations of an advisory committee convened to recommend a cohesive action plan for Hubble observations following the announcement of a detection and subsequent lack of detections by competing groups. Starting in Cycle 26, a Fundamental Physics Initiative seeks proposals for Hubble to make critical contributions to our understanding of dark energy, dark matter, and other aspects of fundamental physics.

These suggestions originate in the community's desire to exploit the singular capabilities of Hubble. The Webb Initiative, for instance, was one of the major outcomes of the HST 2020 call for white papers in the winter of 2014–2015. The special call for Europa proposals came out of the Europa Advisory Committee, formed of external planetary scientists who advised the director on the best way for Hubble to support planning for future missions. The committee sought input from the community, as well as discussions on the priorities of future potential Europa missions with relevant NASA officials. The culmination was a recommendation for a dedicated proposal call, which happened in the fall of 2017. The Fundamental Physics Initiative likewise came out of a committee formed to provide advice on future strategies to implement appropriate observing programs with Hubble. Community members provided input to the recommendations of this committee as well.

A Strategic Initiative to Cement Hubble's UV Legacy

STScI Directors have a long history of strategic use of Director’s Discretionary (DD) time for large observing programs.  The original Hubble Deep Field came out of then-director Bob Williams’ desire to make fundamental advancements in galaxy evolution with the observatory's deep stare. The Hubble Ultra-Deep Field and Hubble Frontier Fields Initiatives had similar origins. These initiatives are different from the targeted observing initiatives described in the previous section, because they come out of DD time. There is a common thread between the two types of initiatives of community involvement. The current STScI Director has assembled a Hubble UV Legacy Working Group chaired by Prof. Sally Oey (University of Michigan) to investigate the use of DD time for fundamental advances in stars and star formation. The key goal is to extend knowledge of the universe through the unique UV observing capabilities available only with Hubble. This came about after consultation with the Space Telescope Users’ Committee and the science community. It will involve between 600 and 1000 orbits, and address science questions large enough that they fall outside of the scope of the normal proposal process. The initiative will include the creation of legacy datasets, as well as theoretical models and simulation data. The working group has been tasked with defining the science case, recommending and prioritizing observations necessary to complete the science goals of the initiative, and identifying coordinated observations that may be necessary to extend the reach of the Hubble observations themselves. The working group is currently meeting, and is expected to produce a white paper on its findings by winter 2019.