TY - JOUR
AU - M. Nowak
AU - S. Lacour
AU - A.-M. Lagrange
AU - P. Rubini
AU - J. Wang
AU - T. Stolker
AU - R. Abuter
AU - A. Amorim
AU - R. Asensio-Torres
AU - M. Bauböck
AU - Jason Dexter
AU - et al.
AB - Context. Methods used to detect giant exoplanets can be broadly divided into two categories: indirect and direct. Indirect methods are more sensitive to planets with a small orbital period, whereas direct detection is more sensitive to planets orbiting at a large distance from their host star. This dichotomy makes it difficult to combine the two techniques on a single target at once.

Aims. Simultaneous measurements made by direct and indirect techniques offer the possibility of determining the mass and luminosity of planets and a method of testing formation models. Here, we aim to show how long-baseline interferometric observations guided by radial-velocity can be used in such a way.

Methods. We observed the recently-discovered giant planet β Pictoris c with GRAVITY, mounted on the Very Large Telescope Interferometer.

Results. This study constitutes the first direct confirmation of a planet discovered through radial velocity. We find that the planet has a temperature of T = 1250 ± 50 K and a dynamical mass of M = 8.2 ± 0.8 MJup. At 18.5 ± 2.5 Myr, this puts β Pic c close to a ‘hot start’ track, which is usually associated with formation via disk instability. Conversely, the planet orbits at a distance of 2.7 au, which is too close for disk instability to occur. The low apparent magnitude (MK = 14.3 ± 0.1) favours a core accretion scenario.

Conclusions. We suggest that this apparent contradiction is a sign of hot core accretion, for example, due to the mass of the planetary core or the existence of a high-temperature accretion shock during formation.
BT - Astronomy & Astrophysics
DA - 2020-10
DO - 10.1051/0004-6361/202039039
N2 - Context. Methods used to detect giant exoplanets can be broadly divided into two categories: indirect and direct. Indirect methods are more sensitive to planets with a small orbital period, whereas direct detection is more sensitive to planets orbiting at a large distance from their host star. This dichotomy makes it difficult to combine the two techniques on a single target at once.

Aims. Simultaneous measurements made by direct and indirect techniques offer the possibility of determining the mass and luminosity of planets and a method of testing formation models. Here, we aim to show how long-baseline interferometric observations guided by radial-velocity can be used in such a way.

Methods. We observed the recently-discovered giant planet β Pictoris c with GRAVITY, mounted on the Very Large Telescope Interferometer.

Results. This study constitutes the first direct confirmation of a planet discovered through radial velocity. We find that the planet has a temperature of T = 1250 ± 50 K and a dynamical mass of M = 8.2 ± 0.8 MJup. At 18.5 ± 2.5 Myr, this puts β Pic c close to a ‘hot start’ track, which is usually associated with formation via disk instability. Conversely, the planet orbits at a distance of 2.7 au, which is too close for disk instability to occur. The low apparent magnitude (MK = 14.3 ± 0.1) favours a core accretion scenario.

Conclusions. We suggest that this apparent contradiction is a sign of hot core accretion, for example, due to the mass of the planetary core or the existence of a high-temperature accretion shock during formation.
PB - EDP Sciences
PY - 2020
EP - L2
T2 - Astronomy & Astrophysics
TI - Direct confirmation of the radial-velocity planet β Pictoris c
UR - http://dx.doi.org/10.1051/0004-6361/202039039
VL - 642
SN - 1432-0746
ER -