Infrared photometry with InGaAs detectors: first light with SPECULOOS
OPEN ACCESS
Loading...
Author / Producer
Date
2024
Publication Type
Conference Paper
ETH Bibliography
yes
OPEN ACCESS
Data
Rights / License
Abstract
We present the photometric performance of SPIRIT, a ground-based near-infrared InGaAs CMOS-based instrument (1280 by 1024 pixels, 12 μm pitch), using on-sky results from the SPECULOOS-Southern Observatory during 2022 – 2023. SPIRIT was specifically designed to optimise time-series photometric precision for observing late M and L type stars. To achieve this, a custom wide-pass filter (0.81 – 1.33 μm, zYJ ) was used, which was also designed to minimise the effects of atmospheric precipitable water vapour (PWV) variability on differential photometry. Additionally, SPIRIT was designed to be maintenance-free by eliminating the need for liquid nitrogen for cooling. We compared SPIRIT’s performance with a deeply-depleted (2048 by 2048 pixels, 13.5 μm pitch) CCD-based instrument (using an I+z’ filter, 0.7 – 1.1 μm) through simultaneous observations. For L type stars and cooler, SPIRIT exhibited better photometric noise performance compared to the CCD-based instrument. The custom filter also significantly minimised red noise in the observed light curves typically introduced by atmospheric PWV variability. In SPIRIT observations, the detector’s read noise was the dominant limitation, although in some cases, we were limited by the lack of comparison stars.
Permanent link
Publication status
published
External links
Book title
Ground-based and Airborne Instrumentation for Astronomy X
Journal / series
Volume
13096
Pages / Article No.
Publisher
SPIE
Event
SPIE Astronomical Telescopes + Instrumentation 2024
Edition / version
Methods
Software
Geographic location
Date collected
Date created
Subject
infrared; CMOS; InGaAs; photometry; PWV; instrumentation; exoplanets; ground-based
Organisational unit
09754 - Queloz, Didier / Queloz, Didier