HATS-18B: AN EXTREME SHORT-PERIOD MASSIVE TRANSITING PLANET SPINNING UP ITS STAR

Journal Article · Tue Nov 01 04:00:00 EDT 2016 · The Astronomical Journal (Online)

DOI:https://doi.org/10.3847/0004-6256/152/5/127· OSTI ID:22862854

Penev, K.; Hartman, J. D.; Bakos, G. Á.; Csubry, Z.; Bhatti, W.; Val-Borro, M. de; Zhou, G. ^[1]; Ciceri, S.; Mancini, L.; Henning, T. ^[2]; Brahm, R.; Jordán, A.; Espinoza, N.; Rabus, M.; Suc, V. ^[3]; Bayliss, D.; Bento, J.; Schmidt, B. ^[4]; Noyes, R. W. ^[5]; others, and

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1. Department of Astrophysical Sciences, Princeton University, NJ 08544 (United States)
2. Max Planck Institute for Astronomy, Heidelberg (Germany)
3. Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago (Chile)
4. Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia)
5. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

We report the discovery by the HATSouth network of HATS-18b: a 1.980±0.077 M{sub J}, 1.337{sub −0.049}{sup +0.102} R{sub J} planet in a 0.8378 day orbit, around a solar analog star (mass 1.037±0.047 M{sub ⊙} and radius 1.020{sub −0.031}{sup +0.057} R{sub ⊙}) with V=14.067±0.040 mag. The high planet mass, combined with its short orbital period, implies strong tidal coupling between the planetary orbit and the star. In fact, given its inferred age, HATS-18 shows evidence of significant tidal spin up, which together with WASP-19 (a very similar system) allows us to constrain the tidal quality factor for Sun-like stars to be in the range of 6.5≲log{sub 10}(Q{sup ∗}/k{sub 2})≲7 even after allowing for extremely pessimistic model uncertainties. In addition, the HATS-18 system is among the best systems (and often the best system) for testing a multitude of star–planet interactions, be they gravitational, magnetic, or radiative, as well as planet formation and migration theories.

• OSTI ID: 22862854
• Journal Information: The Astronomical Journal (Online), Journal Name: The Astronomical Journal (Online) Journal Issue: 5 Vol. 152; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
INTERACTIONS
MASS
ORBITS
PLANETS
QUALITY FACTOR
ROTATION
SATELLITES
SPIN
STARS