In:
The Astrophysical Journal Letters, American Astronomical Society, Vol. 904, No. 2 ( 2020-12-01), p. L25-
Kurzfassung:
We present the direct imaging discovery of a substellar companion to the nearby Sun-like star, HD 33632 Aa, at a projected separation of ∼20 au, obtained with SCExAO/CHARIS integral field spectroscopy complemented by Keck/NIRC2 thermal infrared imaging. The companion, HD 33632 Ab, induces a 10.5 σ astrometric acceleration on the star as detected with the Gaia and Hipparcos satellites. SCExAO/CHARIS JHK (1.1–2.4 μ m) spectra and Keck/NIRC2 L p (3.78 μ m) photometry are best matched by a field L/T transition object: an older, higher-gravity, and less dusty counterpart to HR 8799 cde. Combining our astrometry with Gaia/Hipparcos data and archival Lick Observatory radial velocities, we measure a dynamical mass of 46.4 ± 8 M J and an eccentricity of e 〈 0.46 at 95% confidence. HD 33632 Ab’s mass and mass ratio (4.0% ± 0.7%) are comparable to the low-mass brown dwarf GJ 758 B and intermediate between the more massive brown dwarf HD 19467 B and the (near-)planet-mass companions to HR 2562 and GJ 504. Using Gaia to select for direct imaging observations with the newest extreme adaptive optics systems can reveal substellar or even planet-mass companions on solar system–like scales at an increased frequency compared to blind surveys.
Materialart:
Online-Ressource
ISSN:
2041-8205
,
2041-8213
DOI:
10.3847/2041-8213/abc631
Sprache:
Unbekannt
Verlag:
American Astronomical Society
Publikationsdatum:
2020
ZDB Id:
2207648-7
ZDB Id:
2006858-X
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