Data and code for 'Invisible: Loss of the D-type near-infrared spectral signature of the Jupiter Trojan (2241) Alcathous'

Reduced near-infrared reflectance spectra of the Jupiter Trojan asteroid (2241) Alcathous, obtained with SpeX at the NASA Infrared Telescope Facility on 2016-12-22, 2017-12-30 and 2019-01-20, together with the derived data products and the complete code that produced every number in the accompanying paper. The object had an ordinary D-type near-infrared spectrum in December 2016, at +28.86 ± 3.75 %/µm over 0.80–2.40 µm. Twelve months later the same object measured −2.65 ± 0.78 %/µm. A third spectrum, in January 2019, is also flat. This deposit holds the spectra those numbers were measured from and the code that measured them. Contents: data/ — six reduced reflectance spectra, two reductions of each of three nights, plus the slope of every individual exposure and the test for an absorption band near 0.70–0.75 µm. derived/ — six data products, one per analysis driver: the slopes, the upper limit on a resolved coma, the observing geometry at every epoch at which a near-infrared spectrum of this object exists, the telescope pointing checked against the JPL Horizons ephemeris, the five reference stars as SIMBAD and Gaia DR3 describe them, and a taxonomic census of the Jupiter Trojans. Each file states what it establishes and what it does not. code/ — the modules, drivers, tests and figure scripts that produce all of the above. Not included, and deliberately so. The raw frames are about nineteen gigabytes and are held in the NASA Infrared Telescope Facility Legacy Archive under the observing programmes named in section 2.1 of the paper, which is the right home for them. The two 2007 comparison spectra shown in Figure 2 were obtained by Emery et al. (2011) and by Yang and Jewitt (2011) and are not ours to redistribute; the slopes we measured from them are in derived/slopes.md. Nothing in this deposit requires contacting the authors.