Ralf Scholz (AIP)

Wann Am 13.08.2020 von 14:30 bis 15:30
  • Kolloquium
Wo Cyberspace
Termin übernehmen vCal / iCal

Even in the immediate Solar neighbourhood, within 10 pc from the Sun, we may have still not identified all brown dwarfs (BDs), very low-mass (VLM) stars and white dwarfs (WDs). However, the nearest objects are important for many fields, including extrasolar planets, star formation, space density and stellar encounters, and the detailed investigation of bright representatives of different classes. Proper motion surveys were traditionally used as one of the main tools to find nearby stars. I will show the pre-Gaia progress achieved in the search for missing neighbours thanks to many ground-based efforts, and highlight a few important discoveries made at AIP. Problems but also the potential for discoveries in the Gaia data will be demonstrated. This will include a report on new ultracool dwarfs (a mix of VLM stars and BDs) recently found within 20 pc in Gaia DR2. Some particularly interesting nearby WDs discovered with help from Gaia will also be mentioned. Finally, the closest (<< 1 pc) known flyby candidates to the Sun in the recent past and more distant future will be discussed in light of the Gaia survey, from which the discovery of many more such candidates can be expected because of its unbiased survey with respect to proper motions.