CaltechAUTHORS
Published September 1, 2022 | Version public
Journal Article Metadata-only

A Tendency Toward Alignment in Single-star Warm-Jupiter Systems

Creators

  • 1. ROR icon Massachusetts Institute of Technology
  • 2. ROR icon Yale University
  • 3. ROR icon Indiana University Bloomington
  • 4. ROR icon National Astronomical Observatories
  • 5. ROR icon University of Chinese Academy of Sciences
  • 6. ROR icon Princeton University
  • 7. ROR icon University of California, Berkeley
  • 8. ROR icon University of Southern Queensland
  • 9. ROR icon California Institute of Technology
  • 10. ROR icon NOIRLab
  • 11. ROR icon University of Hawaii at Manoa
  • 12. ROR icon University of California, Irvine

Abstract

The distribution of spin–orbit angles for systems with wide-separation, tidally detached exoplanets offers a unique constraint on the prevalence of dynamically violent planetary evolution histories. Tidally detached planets provide a relatively unbiased view of the primordial stellar obliquity distribution, as they cannot tidally realign within the system lifetime. We present the third result from our Stellar Obliquities in Long-period Exoplanet Systems (SOLES) survey: a measurement of the Rossiter–McLaughlin effect across two transits of the tidally detached warm Jupiter TOI-1478 b with the WIYN/NEID and Keck/HIRES spectrographs, revealing a sky-projected spin–orbit angle λ = 6.2^(+5.9°)_(−5.5). Combining this new measurement with the full set of archival obliquity measurements, including two previous constraints from the SOLES survey, we demonstrate that, in single-star systems, tidally detached warm Jupiters are preferentially more aligned than closer-orbiting hot Jupiters. This finding has two key implications: (1) planets in single-star systems tend to form within aligned protoplanetary disks, and (2) warm Jupiters form more quiescently than hot Jupiters, which, in single-star systems, are likely perturbed into a misaligned state through planet–planet interactions in the post-disk-dispersal phase. We also find that lower-mass Saturns span a wide range of spin–orbit angles, suggesting a prevalence of planet–planet scattering and/or secular mechanisms in these systems.

Additional Information

We thank our anonymous reviewer for their comments that have strengthened this manuscript. Over the duration of this project, M.R. was supported by the Heising–Simons Foundation 51 Pegasi b Fellowship and by the National Science Foundation Graduate Research Fellowship Program under grant No. DGE-1752134. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. This work is supported by the Astronomical Big Data Joint Research Center, cofounded by the National Astronomical Observatories, Chinese Academy of Sciences, and Alibaba Cloud. This research has made use of the Keck Observatory Archive (KOA), which is operated by the W. M. Keck Observatory and the NASA Exoplanet Science Institute (NExScI), under contract with the National Aeronautics and Space Administration. This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This paper contains data taken with the NEID instrument, which was funded by the NASA-NSF Exoplanet Observational Research (NN-EXPLORE) partnership and built by Pennsylvania State University. NEID is installed on the WIYN 3.5 m telescope at KPNO, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the NSF. The NEID archive is operated by the NASA Exoplanet Science Institute at the California Institute of Technology. We thank the NEID Queue Observers and WIYN Observing Associates for their skillful execution of our NEID observations. The authors are honored to be permitted to conduct astronomical research on Iolkam Du'ag (Kitt Peak), a mountain with particular significance to the Tohono O'odham. Facilities: Keck: I (HIRES) - , WIYN (NEID) - , Exoplanet Archive - , Extrasolar Planets Encyclopaedia - . Software: numpy (Oliphant 2006; Walt et al. 2011; Harris et al. 2020), matplotlib (Hunter 2007), pandas (McKinney et al. 2010), scipy (Virtanen et al. 2020), allesfitter (Günther & Daylan 2021), emcee (Foreman-Mackey et al. 2013), MESA (Paxton et al. 2010, 2013, 2015).

Additional details

Identifiers

Eprint ID
116625
Resolver ID
CaltechAUTHORS:20220829-468372700.779

Funding

National Science Foundation
DGE-1752134
Heising–Simons Foundation 51 Pegasi b Fellowship
Astronomical Big Data Joint Research Center
Keck Observatory Archive (KOA)
NASA Exoplanet Archive
Exoplanet Exploration Program
NASA-NSF Exoplanet Observational Research (NN-EXPLORE)

Dates

Created
2022-09-07
Created from EPrint's datestamp field
Updated
2022-10-05
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Astronomy Department