Many of the compact extragalactic radio sources that are used as fiducial points to define the celestial reference frame are known to have proper motions detectable with long-term geodetic/astrometric very long baseline interferometry (VLBI) measurements. These changes can be as high as several hundred microarcseconds per year for certain objects

We examine the spectrum in the vicinity of the NH3360 index of Davidge & Clark, which was defined to measure the NH absorption around 3360 Å and shows almost no trend with velocity dispersion, unlike other N-sensitive indices, which show a strong trend. Computing the effect of individual elements on the integrated spectrum with synthetic stellar

Context. Near-Earth asteroid (175706) 1996 FG3 is the primary target of the ESA Marco Polo-R mission, which was selected for the assessment study phase of ESA M3 missions. This is a primitive (C-type), binary asteroid that will allow new research to be performed. The primary is a rapidly rotating (3.6 h) small asteroid (1.4 km diameter) that is

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We compare 13 near-infrared (0.8-2.4 μm) spectra of two low albedo C complex outer-belt asteroid families: Themis and Veritas. The disruption ages of these two families lie at opposite extremes: 2.5 ± 1.0 Gyr and 8.7 ± 1.7 Myr, respectively. We found striking differences between the two families, which show a range of spectral shapes and slopes

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