Synthetic CO J(2−1) spectra (blue) superimposed on observed IRAM spectra (black). Top: average data from 29 December 2007 to 11 January 2011 (mean r_h = 6.1 au and mean ∆ = 5.5 au). The production rate in the sunward jet of 45° semi-aperture is 2.7 × 10²⁸ s⁻¹, and the total CO production rate is 4.5 × 10²⁸ s⁻¹. Bottom: average November 2021 spectrum. The production rate in the sunward jet is 1.7 × 10²⁸ s⁻¹, and the total production rate is 3.2 × 10²⁸ s⁻¹. The outflow velocities within and outside the jet are assumed to be υ_exp = 0.5 and 0.3 km s⁻¹, respectively.