Data analysis of laboratory photometry experiments with GSENSE 1081BSI CMOS detectors

Abstract

The Earth 2.0 (ET) mission, led by China, aims to detect over 50,000 exoplanets, including potentially habitable Earth-like planets around Sun-like stars (”Earth 2.0s”), cold low-mass planets, and free-floating planets. The mission will employ six 28-cm telescopes to conduct ultra-high-precision photometric monitoring for the detection of transiting planets. To verify that the telescopes can reliably detect exoplanet transit events, we have developed a high-precision photometry testbed. This system evaluates selected CMOS detectors for their ability to detect Earth 2.0 transit signals, specifically those exhibiting photometric variations at the 84-ppm level. This manuscript presents the laboratory set up with data processing and analysis pipeline, including image calibration, aperture photometry, cotrending and detrending algorithms, precision estimation, and the identification of simulated transit signals. Preliminary results show that, for simulated sources equivalent to a 12.5-mag Sun-like star, a instrumental photometric precision of 10 ppm can be approached over a 6.5-hour timescale. Moreover, we have successfully recovered simulated Earth 2.0-like transit signals with a duration of ∼13 hours, corresponding to a planet transiting a G-type star within its habitable zone.