Hot Stuff for One Year (HSOY) - A 583 million star proper motion catalogue derived from Gaia DR1 and PPMXL

Understand

Recently, the first installment of data from ESA's Gaia astrometric satellite mission (Gaia-DR1) was released, containing positions of more than 1 billion stars with unprecedented precision, as well as only proper motions and parallaxes, however only for a subset of 2 million objects.

• The second release, due in late 2017 or early 2018, will include those quantities for most objects.
• In order to provide a dataset that bridges the time gap between the Gaia-DR1 and Gaia-DR2 releases and partly remedies the lack of proper motions in the former, HSOY ("Hot Stuff for One Year") was created as a hybrid catalogue between Gaia-DR1 and ground-based astrometry, featuring proper motions (but no parallaxes) for a large fraction of the DR1 objects.
• While not attempting to compete with future Gaia releases in terms of data quality or number of objects, the aim of HSOY is to provide improved proper motions partly based on Gaia data, allowing some studies to be carried out just now or as pilot studies for later larger projects requiring higher-precision data.