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Statistical properties of Hipparcos 2, caveats on its use, and a recalibration of the intermediate astrometric data
Brandt, Timothy D.; Brandt, G. Mirek; Michalik, Daniel
We revisit the Hipparcos 2007 re-reduction and find improvements to the catalogue by leveraging Gaia EDR3. We show that including a constant residual offset and additional dispersion (two free parameters in total) in the Hipparcos 2007 Intermediate Astrometric Data (IAD) creates a new catalogue with significantly better agreement with Gaia EDR3. T…
Extending time-series models for irregular observational gaps with a moving average structure for astronomical sequences
Elorrieta, F.; Eyheramendy, S.; Palma, W. +1 more
In this study, we introduce a novel moving-average model for analyzing stationary time-series observed irregularly in time. The process is strictly stationary and ergodic under normality and weakly stationary when normality is not assumed. Maximum likelihood (ML) estimation can be efficiently carried out through a Kalman algorithm obtained from th…