1. SPHEREx LEGACY SCIENCE
Mike Werner and Peter Capak

2. Legacy Science - A Definition
Legacy Science encompasses all possible uses of the SPHEREx data other than the three defining science themes
As a unique all sky spectroscopic survey, SPHEREx follows previous surveys from IRAS to Planck, and promises to replicate the scientific productivity of these surveys
Consider the impact of adding a spectrum to 2-MASS and WISE photometric surveys
Legacy Science is implicit in the SPHEREx data, but special tools and data products may be required to exploit it fully
Such items were considered an enhancement to the SMEX mission but are now part of the SPHEREx MIDEX baseline
The promise of Legacy Science has been a consistent plus for SPHEREx in evaluation of Step 1 and Step 2 proposals
It is a major objective of this workshop to describe Legacy Science opportunities and the software required to use them optimally
This talk will seed the process with a few examples

3. Mission timelines highlight Legacy Science synergies, a theme of this conference

4. Legacy Science topics in SMEX proposal

5. We listed data products (L) and tools (R) to exploit these topics

6. Proposed Legacy products for MIDEX
Within the SPHEREx team, we have started to list specific legacy products to be developed as part of the funded activity. Examples and motivation include
Cometary spectra – address role of CO and CO2 in driving activity in around 100 comets. Synergistic with LSST estimates of cometary activity
Properties of stars which host transiting planets – in combination with GAIA, determine accurate radii for thousands of star, and hence planets, identified by Kepler, K2, and TESS [and future exoplanet missions]
Spectra of ~10,000 late M, L, T, and Y dwarfs – in combination with WISE proper motion studies, characterize sun’s nearest neighbors. Refine models and find transitional objects with unusual colors
Current thinking is to list other factors, e.g. ancillary data needed, possible applications of data, special considerations beyond what is needed for basic pipeline [improved calibration, moving targets, etc]

7. Conclusions
Legacy Science has been and will be a major argument for the selection of SPHEREx and an important part of the legacy of the mission
We look forward to augmenting and enhancing the ideas presented above as a result of this conference
Please share your ideas about SPHEREx Legacy Science during your talks and in the discussion sections, and in your contributed white papers
We will enlist your help in producing a new white paper and, possibly, in producing text for the proposal. Time is short. Propsal due 1 June, hope to post white paper mid-April