Searching sub-stellar objects in DR1-TGAS, effectiveness and efficiency of Gaias' astrometry

Abstract

We used 1,477,047 data from DR1-TGAS, in order to analyse the minimum require- ments of accuracy, necessary to detect sub-stellar objects in the astrometric mea- surements of Gaia. We found that the first set of data (DR1) does not have enough accuracy, so sub-stellar objects can not be easily detected. Barely, it would be possible to detect jovian and higher mass objects, with orbital periods over 5 years. We made the calculations of the minimum values of the astrometric angle produced by an or- biting sub-stellar object using a range of different masses. We estimate the efficiency and effectiveness of the DR1-TGAS data in order to detect sub-stellar objects and the minimum accuracy that Gaia would be required to detect these objects using the datasets that the mission will release in the near future.

22 pages, 7 figures, Submited to Planetary and Space Science

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