Astrophysics with New Horizons: Making the Most of a Generational Opportunity
We have analyzed data from the Long Range Reconnaissance Imager (LORRI) instrument on NASA's New Horizons mission acquired during cruise phase outside the orbit of Jupiter, and find a statistical upper limit on the optical background's (COB) brightness similar to the integrated light from galaxies. A comparison of the COB intensity to the surface brightness arising from known galaxy populations can reveal the presence of diffuse backgrounds produced by more exotic phenomena such as the decay of particle species outside the standard model or light from objects outside of galaxies. We conclude that a carefully performed survey with LORRI could produce a definitive measurement of the diffuse light in the local universe, and a tight constraint on the light from galaxies in the optical wavebands. In addition to cosmic background measurements, several key astrophysics programs could also be carried out with New Horizons’ instrumental suite, including: (i) studies of interplanetary light in the outer solar system, (ii) a measurement of the local UV background; (iii) detection and mass determinations for Extra-solar planets and possibly even strutcures around them, and (iv) time-domain and target of opportunity observations. A relatively modest extension to New Horizons beyond the current KBO mission dedicated to astrophysics would utilize a once-in-a-lifetime opportunity and enable truly unique measurements not possible from ~1 AU.