A near-Sun Solar System Twilight Survey with LSST

TL;DR

This paper proposes a twilight survey strategy for LSST to maximize near-Sun Solar System observations, covering new sky regions and enhancing science for NEOs, comets, and transient objects, while enabling synergy with space missions like NEOCam.

Contribution

It introduces a novel twilight survey approach for LSST that extends its seasonal reach and improves near-Sun Solar System object detection and follow-up capabilities.

Findings

Survey will cover 50 sq. deg. per night in the morning sky.

Enables first and last look at transient objects in each field.

Maximizes overlap with NEOCam and other space missions.

Abstract

We propose a LSST Solar System near-Sun Survey, to be implemented during twilight hours, that extends the seasonal reach of LSST to its maximum as fresh sky is uncovered at about 50 square degrees per night (1500 sq. deg. per lunation) in the morning eastern sky, and surveyable sky is lost at the same rate to the western evening sky due to the Earth's synodic motion. By establishing near-horizon fence post picket lines to the far west and far east we address Solar System science use cases (including Near Earth Objects, Interior Earth Objects, Potentially Hazardous Asteroids, Earth Trojans, near-Sun asteroids, sun-grazing comets, and dormant comets) as well as provide the first look and last look that LSST will have at the transient and variable objects within each survey field. This proposed near-Sun Survey will also maximize the overlap with the field of regard of the proposed NEOCam spacecraft that will be stationed at the Earth's L1 Lagrange point and survey near quadrature with the Sun. This will allow LSST to incidently follow-up NEOCam targets and vice-versa (as well as targets from missions such as Euclid), and will roughly correspond to the Earth's L4 and L5 regions.