FRIENDS OF HOT JUPITERS. II. NO CORRESPONDENCE BETWEEN HOT-JUPITER SPIN-ORBIT MISALIGNMENT AND THE INCIDENCE OF DIRECTLY IMAGED STELLAR COMPANIONS

Journal Article · Fri Feb 20 04:00:00 EST 2015 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/800/2/138· OSTI ID:22522507

Ngo, Henry; Knutson, Heather A.; Hinkley, Sasha; Batygin, Konstantin ^[1]; Crepp, Justin R.; Bechter, Eric B. ^[2]; Howard, Andrew W. ^[3]; Johnson, John A. ^[4]; Morton, Timothy D. ^[5]

---

1. Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA (United States)
2. Department of Physics, University of Notre Dame, Notre Dame, IN (United States)
3. Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI (United States)
4. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
5. Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA (United States)

Multi-star systems are common, yet little is known about a stellar companion's influence on the formation and evolution of planetary systems. For instance, stellar companions may have facilitated the inward migration of hot Jupiters toward to their present day positions. Many observed short-period gas giant planets also have orbits that are misaligned with respect to their star's spin axis, which has also been attributed to the presence of a massive outer companion on a non-coplanar orbit. We present the results of a multi-band direct imaging survey using Keck NIRC2 to measure the fraction of short-period gas giant planets found in multi-star systems. Over three years, we completed a survey of 50 targets ('Friends of Hot Jupiters') with 27 targets showing some signature of multi-body interaction (misaligned or eccentric orbits) and 23 targets in a control sample (well-aligned and circular orbits). We report the masses, projected separations, and confirmed common proper motion for the 19 stellar companions found around 17 stars. Correcting for survey incompleteness, we report companion fractions of 48% ± 9%, 47% ± 12%, and 51% ± 13% in our total, misaligned/eccentric, and control samples, respectively. This total stellar companion fraction is 2.8σ larger than the fraction of field stars with companions approximately 50-2000 AU. We observe no correlation between misaligned/eccentric hot Jupiter systems and the incidence of stellar companions. Combining this result with our previous radial velocity survey, we determine that 72% ± 16% of hot Jupiters are part of multi-planet and/or multi-star systems.

• OSTI ID: 22522507
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 800; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
APPROXIMATIONS
CONTROL
CORRELATIONS
ECLIPSE
JUPITER PLANET
MASS
ORBITS
PROPER MOTION
RADIAL VELOCITY
RESOLUTION
SATELLITES
SPIN
STAR EVOLUTION
STARS