MASCARA-1 b

• Published in: Astronomy and astrophysics (Berlin) Vol. 606
• Main Authors: Talens, G. J. J., Albrecht, S., Spronck, J. F. P., Lesage, A.-L., Otten, G. P. P. L., Stuik, R., Van Eylen, V., Van Winckel, H., Pollacco, D., McCormac, J., Grundahl, F., Fredslund Andersen, M., Antoci, V., Snellen, I. A. G.
• Format: Journal Article
• Language: English
• Published: Heidelberg EDP Sciences 01.10.2017
• Subjects: Extrasolar planets; Gas giant planets; Jupiter; Misalignment; Planet formation; planetary systems; Sky; stars: individual: MASCARA-1; Stellar rotation
• ISSN: 0004-6361; 1432-0746
• DOI: 10.1051/0004-6361/201731282

We report the discovery of MASCARA-1 b, which is the first exoplanet discovered with the Multi-site All-Sky CAmeRA (MASCARA). This exoplanet is a hot Jupiter orbiting a bright mV = 8.3, rapidly rotating (vsini⋆ > 100 km s-1) A8 star with a period of 2.148780 ± 8 × 10-6 days. The planet has a mass and radius of 3.7 ± 0.9 MJup and 1.5 ± 0.3 RJup, respectively. As with most hot Jupiters transiting early-type stars, we find a misalignment between the planet orbital axis and the stellar spin axis, which may be a signature of the formation and migration histories of this family of planets. MASCARA-1 b has a mean density of 1.5 ± 0.9 g cm-3 and an equilibrium temperature of 2570+50-30K, that is one of the highest temperatures known for a hot Jupiter to date. The system is reminiscent of WASP-33, but the host star lacks apparent delta-scuti variations, making the planet an ideal target for atmospheric characterization. We expect this to be the first of a series of hot Jupiters transiting bright early-type stars that will be discovered by MASCARA.