학술논문
Precise near-infrared photometry, accounting for precipitable water vapour at SPECULOOS Southern Observatory
Document Type
Working Paper
Author
Pedersen, Peter P.; Murray, C. A.; Queloz, D.; Gillon, M.; Demory, B. O.; Triaud, A. H. M. J.; de Wit, J.; Delrez, L.; Dransfield, G.; Ducrot, E.; Garcia, L. J.; Chew, Y. Gómez Maqueo; Günther, M. N.; Jehin, E.; McCormac, J.; Niraula, P.; Pozuelos, F. J.; Rackham, B. V.; Schanche, N.; Sebastian, D.; Thompson, S. J.; Timmermans, M.; Wells, R.
Source
Subject
Language
Abstract
The variability induced by precipitable water vapour (PWV) can heavily affect the accuracy of time-series photometric measurements gathered from the ground, especially in the near-infrared. We present here a novel method of modelling and mitigating this variability, as well as open-sourcing the developed tool -- Umbrella. In this study, we evaluate the extent to which the photometry in three common bandpasses (r', i', z'), and SPECULOOS' primary bandpass (I+z'), are photometrically affected by PWV variability. In this selection of bandpasses, the I+z' bandpass was found to be most sensitive to PWV variability, followed by z', i', and r'. The correction was evaluated on global light curves of nearby late M- and L-type stars observed by SPECULOOS' Southern Observatory (SSO) with the I+z' bandpass, using PWV measurements from the LHATPRO and local temperature/humidity sensors. A median reduction in RMS of 1.1% was observed for variability shorter than the expected transit duration for SSO's targets. On timescales longer than the expected transit duration, where long-term variability may be induced, a median reduction in RMS of 53.8% was observed for the same method of correction.
Comment: Accepted for publication in MNRAS, 10 pages, 7 figures, 3 tables
Comment: Accepted for publication in MNRAS, 10 pages, 7 figures, 3 tables