The Astronomical Journal (Jan 2024)
The OATMEAL Survey. I. Low Stellar Obliquity in the Transiting Brown Dwarf System GPX-1
- Steven Giacalone,
- Fei Dai,
- J. J. Zanazzi,
- Andrew W. Howard,
- Courtney D. Dressing,
- Joshua N. Winn,
- Ryan A. Rubenzahl,
- Theron W. Carmichael,
- Noah Vowell,
- Aurora Kesseli,
- Samuel Halverson,
- Howard Isaacson,
- Max Brodheim,
- William Deich,
- Benjamin J. Fulton,
- Steven R. Gibson,
- Grant M. Hill,
- Bradford Holden,
- Aaron Householder,
- Stephen Kaye,
- Russ R. Laher,
- Kyle Lanclos,
- Joel Payne,
- Erik A. Petigura,
- Arpita Roy,
- Christian Schwab,
- Abby P. Shaum,
- Martin M. Sirk,
- Chris Smith,
- Guðmundur Stefánsson,
- Josh Walawender,
- Sharon X. Wang,
- Lauren M. Weiss,
- Sherry Yeh
Affiliations
- Steven Giacalone
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- Fei Dai
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]; Institute for Astronomy, University of Hawai’i , 2680 Woodlawn Drive, Honolulu, HI 96822, USA; Division of Geological and Planetary Sciences , 1200 E California Boulevard, Pasadena, CA 91125, USA
- J. J. Zanazzi
- ORCiD
- Department of Astronomy, University of California Berkeley , Berkeley, CA 94720, USA
- Andrew W. Howard
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- Courtney D. Dressing
- ORCiD
- Department of Astronomy, University of California Berkeley , Berkeley, CA 94720, USA
- Joshua N. Winn
- ORCiD
- Department of Astrophysical Sciences, Princeton University , Princeton, NJ 08544, USA
- Ryan A. Rubenzahl
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- Theron W. Carmichael
- ORCiD
- Institute for Astronomy, University of Hawai’i , 2680 Woodlawn Drive, Honolulu, HI 96822, USA
- Noah Vowell
- ORCiD
- Center for Astrophysics ∣Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA; Center for Data Intensive and Time Domain Astronomy, Department of Physics and Astronomy, Michigan State University , East Lansing, MI 48824, USA
- Aurora Kesseli
- ORCiD
- IPAC , Mail Code 100-22, Caltech, 1200 E. California Boulevard, Pasadena, CA 91125, USA
- Samuel Halverson
- ORCiD
- Jet Propulsion Laboratory , 4800 Oak Grove Drive, Pasadena, CA 91109, USA
- Howard Isaacson
- ORCiD
- 501 Campbell Hall, University of California at Berkeley , Berkeley, CA 94720, USA; Centre for Astrophysics, University of Southern Queensland , Toowoomba, QLD, Australia
- Max Brodheim
- ORCiD
- W. M. Keck Observatory , Waimea, HI 96743, USA
- William Deich
- ORCiD
- University of California Observatories , 1156 High Street, Santa Cruz, CA 95064, USA
- Benjamin J. Fulton
- ORCiD
- NASA Exoplanet Science Institute/Caltech-IPAC , California Institute of Technology, Pasadena, CA 91125, USA
- Steven R. Gibson
- ORCiD
- Caltech Optical Observatories , Pasadena, CA 91125, USA
- Grant M. Hill
- ORCiD
- W. M. Keck Observatory , 65-1120 Mamalahoa Highway, Kamuela, HI 96743, USA
- Bradford Holden
- ORCiD
- University of California Observatories , 1156 High Street, Santa Cruz, CA 95064, USA
- Aaron Householder
- ORCiD
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology , Cambridge, MA 02139, USA; Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , Cambridge, MA 02139, USA
- Stephen Kaye
- Caltech Optical Observatories, California Institute of Technology , Pasadena, CA 91125, USA
- Russ R. Laher
- ORCiD
- NASA Exoplanet Science Institute/Caltech-IPAC , 1200 E California Boulevard, Pasadena, CA 91125, USA
- Kyle Lanclos
- ORCiD
- W. M. Keck Observatory , 65-1120 Mamalahoa Highway, Kamuela, HI 96743, USA
- Joel Payne
- ORCiD
- W. M. Keck Observatory , 65-1120 Mamalahoa Highway, Kamuela, HI 96743, USA
- Erik A. Petigura
- ORCiD
- Department of Physics & Astronomy, University of California Los Angeles , Los Angeles, CA 90095, USA
- Arpita Roy
- ORCiD
- Astrophysics & Space Institute , Schmidt Sciences, New York, NY 10011, USA
- Christian Schwab
- ORCiD
- School of Mathematical and Physical Sciences, Macquarie University , Balaclava Road, North Ryde, NSW 2109, Australia
- Abby P. Shaum
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- Martin M. Sirk
- ORCiD
- Space Sciences Laboratory, University of California , Berkeley, CA 94720, USA
- Chris Smith
- Space Sciences Laboratory, University of California , Berkeley, CA 94720, USA
- Guðmundur Stefánsson
- ORCiD
- Anton Pannekoek Institute for Astronomy, University of Amsterdam , Science Park 904, 1098 XH Amsterdam, The Netherlands
- Josh Walawender
- ORCiD
- W. M. Keck Observatory , 65-1120 Mamalahoa Highway, Kamuela, HI 96743, USA
- Sharon X. Wang
- ORCiD
- Department of Astronomy, Tsinghua University , Beijing 100084, People’s Republic of China
- Lauren M. Weiss
- ORCiD
- Department of Physics and Astronomy, University of Notre Dame , Notre Dame, IN 46556, USA
- Sherry Yeh
- ORCiD
- W. M. Keck Observatory , 65-1120 Mamalahoa Highway, Kamuela, HI 96743, USA
- DOI
- https://doi.org/10.3847/1538-3881/ad785a
- Journal volume & issue
-
Vol. 168,
no. 5
p. 189
Abstract
We introduce the OATMEAL survey, an effort to measure the obliquities of stars with transiting brown dwarf companions. We observed a transit of the close-in ( P _orb = 1.74 days) brown dwarf GPX-1 b using the Keck Planet Finder spectrograph to measure the sky-projected angle between its orbital axis and the spin axis of its early F-type host star ( λ ). We measured λ = 6.°9 ± 10.°0, suggesting an orbit that is prograde and well aligned with the stellar equator. Hot Jupiters around early F stars are frequently found to have highly misaligned orbits, with polar and retrograde orbits being commonplace. It has been theorized that these misalignments stem from dynamical interactions, such as von Zeipel–Kozai–Lidov cycles, and are retained over long timescales due to weak tidal dissipation in stars with radiative envelopes. By comparing GPX-1 to similar systems under the frameworks of different tidal evolution theories, we argued that the rate of tidal dissipation is too slow to have re-aligned the system. This suggests that GPX-1 may have arrived at its close-in orbit via coplanar high-eccentricity migration or migration through an aligned protoplanetary disk. Our result for GPX-1 is one of few measurements of the obliquity of a star with a transiting brown dwarf. By enlarging the number of such measurements and comparing them with hot-Jupiter systems, we will more clearly discern the differences between the mechanisms that dictate the formation and evolution of both classes of objects.
Keywords
