A Compact and Lightweight Fibered Photometer for the PicSat Mission

TL;DR

This paper presents a compact, lightweight fibered photometer designed for the PicSat nanosatellite, enabling high-precision photometry within strict size and power constraints for astronomical observations.

Contribution

It introduces a novel opto-mechanical payload integrating a small telescope, fiber injection, and fine pointing system for nanosatellite-based high-precision photometry.

Findings

Achieves at least 200 ppm/hr photometric precision

Uses a 3.5 cm aperture telescope with fiber injection

Incorporates a two-axis piezoelectric pointing system

Abstract

PicSat is a nanosatellite developed to observe the transit of the giant planet beta Pictoris b, expected in late 2017. Its science objectives are: the observation of the transit of the giant planet's Hill sphere, the detection of exocomets in the system, and the fine monitoring of the circumstellar disk inhomogeneities. To answer these objectives without exceeding the possibilities of a 3-unit Cubesat in terms of mass and power budget, a small but ambitious 2 kg opto-mechanical payload was designed. The instrument, specifically made for high precision photometry, uses a 3.5 cm effective aperture telescope which injects the light in a single-mode optical fiber linked to an avalanche photodiode. To ensure the stability of the light injection in the fiber, a fine pointing system based on a two-axis piezoelectric actuation system, is used. This system will achieve a sub-arcsecond precision, and ensure that an overall photometric precision of at least 200 ppm/hr can be reached.