An adaptive optics upgrade for the Automated Planet Finder Telescope using an adaptive secondary mirror

TL;DR

This paper proposes an adaptive optics upgrade for the Automated Planet Finder Telescope using a new adaptive secondary mirror, aiming to improve exoplanet radial velocity measurements by reducing atmospheric turbulence effects.

Contribution

It introduces a novel adaptive secondary mirror integrated into the APF telescope, utilizing advanced deformable mirror technology to enhance observational efficiency.

Findings

Simulations show more than doubling of light concentration on spectrograph slit.

The upgrade will improve observing efficiency for dim targets (I=14).

The system will be among the first to pair an ASM with a radial velocity spectrograph.

Abstract

As we enter the era of TESS and JWST, instrumentation that can carry out radial velocity measurements of exoplanet systems is in high demand. We will address this demand by upgrading the UC Lick Observatory's 2.4-meter Automated Planet Finder (APF) telescope with an adaptive optics (AO) system. The AO upgrade will be directly integrated into the APF telescope by replacing the telescope's static secondary mirror with a 61-actuator adaptive secondary mirror (ASM) to minimize the disturbance to the spectrograph optics. This upgrade is enabled by The Netherlands Organization for Applied Scientific Research's (TNO) large-format deformable mirror technology, which will be constructed using a new style of high-efficiency hybrid-variable reluctance actuator. We outline the technical design and manufacturing plan for the proposed APF AO upgrade and simulate the improvement to the science yield using HCIpy. Our simulations predict the AO upgrade will reduce the PSF instabilities due to atmospheric turbulence, concentrating the light on the spectrograph slit by a multiplicative factor of more than two (doubling the telescope's observing efficiency) for targets as dim as I = 14. When completed, the APF adaptive secondary mirror will be among the first pairings of an ASM with a radial velocity spectrograph and become a pathfinder for similar AO systems in telescopes of all sizes.