Young suns and infant planets: probing the origins of solar systems

Bohn, A.J. (2021)

Doctoral Thesis

Even though more than 4000 extra-solar planets are known today, only a small fraction of these has been captured in an image. To better understand the planet formation mechanisms in solar-like environments we started the Young Suns Exoplanet Survey (YSES). YSES targets a homogeneous sample of seventy young (~15Myr), Sun-like stars of the Scorpius-Centaurus association to search for sub-stellar companions. High-contrast imaging observations that were collected with the SPHERE instrument at the Very Large Telescope revealed (i) a shadowed transition disk around Wray 15-788 that shows significant signs of ongoing planet formation and (ii) one of the lowest-mass companions imaged to date: YSES 2b has a mass of 6.5 Jupiter masses and is orbiting its solar-mass primary at a separation of 110 au. Most intriguing, though, was (iii) the discovery of the first directly imaged multi-planet system around a Sun-like star. The detection of two gas-giant companions of 14±3 and 6±1 Jupiter masses that are orbiting YSES 1 at separations of 160 au and 320 au, respectively, provides important implications for the outer architecture of planetary systems and the underlying formation mechanisms.

• Exoplanets
• Direct imaging
• Exoplanet formation
• Exoplanet atmospheres
• Solar-type stars
• Near infrared astronomy
• Very Large Telescope

• All authors: Bohn, A.J.
• Supervisor: Keller, C.U.
• Co-supervisor: Kenworthy, M.A.; Snik, F.
• Committee: Röttgering, H.J.A.; Snellen, I.A.G.; Biller, B.A.; Hinz, P.M.; Konopacky, Q.M.; Lagrange, A.M.
• Qualification: Doctor (dr.)
• Awarding Institution: Leiden Observatory, Faculty of Science, Leiden University
• Date: 2021-09-22
• ISBN (print): 9789464192629