Free Access

Fig. 3.

image

Panel a: Near-IR spectrum of 2I/2019 Q4 (Borisov) in comparison with NIR spectrum of 1I/’Oumuamua, taken from Fitzsimmons et al. (2018). Both ISOs appear featureless and the spectral slopes of the two NIR spectra are comparable. Panel b: comparison between the spectrum of 2I and those of Solar System comets and asteroids. The spectrum of C/2013 US10 is from Protopapa et al. (2018), the spectrum of 6P/d’Arrest from Yang et al. (2009), and the three asteroid spectral classes from DeMeo et al. (2009).

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.