An Obliquity Measurement of the Hot Neptune TOI-1694b

Fuente: arXiv
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Hauptverfasser: Handley, Luke B., Howard, Andrew W., Rubenzahl, Ryan A., Dai, Fei, Tyler, Dakotah, Lee, Rena A., Giacalone, Steven, Isaacson, Howard, Householder, Aaron, Halverson, Samuel, Roy, Arpita, Walawender, Josh
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Veröffentlicht: 2024
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author Handley, Luke B.
Howard, Andrew W.
Rubenzahl, Ryan A.
Dai, Fei
Tyler, Dakotah
Lee, Rena A.
Giacalone, Steven
Isaacson, Howard
Householder, Aaron
Halverson, Samuel
Roy, Arpita
Walawender, Josh
author_facet Handley, Luke B.
Howard, Andrew W.
Rubenzahl, Ryan A.
Dai, Fei
Tyler, Dakotah
Lee, Rena A.
Giacalone, Steven
Isaacson, Howard
Householder, Aaron
Halverson, Samuel
Roy, Arpita
Walawender, Josh
contents We present spectral observations of the multiplanet host TOI-1694 during the transit of TOI-1694b, a 26.1 $M_\oplus$ hot Neptune with a 3.77-day orbit. By analyzing radial velocities obtained from the Keck Planet Finder, we modeled the Rossiter-McLaughlin effect and constrained the sky-projected obliquity to ${9\degree}^{+22\degree}_{-18\degree}$, which is strong evidence for a nearly aligned orbit. TOI-1694b is one of fewer than ten small planets accompanied by confirmed outer giant planets for which the obliquity has been measured. We consider the significance of the outer planet TOI-1694c, a Jupiter-mass planet with a 1-year orbit, and its potential role in influencing the orbit of TOI-1694b to its current state. Incorporating our measurement, we discuss the bifurcation in hot Neptune obliquities and present evidence for an independent polar population. The observed polar planets nearly ubiquitously have periods of $\le 6$ days and mass ratios of $10^{-4}$. Early perturbations by outer companions from resonance crossings in the disk-dispersal stage provide the most compelling explanation for this population. Systems which lack the necessary configuration will retain their primordial obliquity, since hot Neptunes lack the angular momentum needed to realign their hosts on relevant timescales.
format Preprint
id arxiv_https___arxiv_org_abs_2412_07950
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle An Obliquity Measurement of the Hot Neptune TOI-1694b
Handley, Luke B.
Howard, Andrew W.
Rubenzahl, Ryan A.
Dai, Fei
Tyler, Dakotah
Lee, Rena A.
Giacalone, Steven
Isaacson, Howard
Householder, Aaron
Halverson, Samuel
Roy, Arpita
Walawender, Josh
Earth and Planetary Astrophysics
We present spectral observations of the multiplanet host TOI-1694 during the transit of TOI-1694b, a 26.1 $M_\oplus$ hot Neptune with a 3.77-day orbit. By analyzing radial velocities obtained from the Keck Planet Finder, we modeled the Rossiter-McLaughlin effect and constrained the sky-projected obliquity to ${9\degree}^{+22\degree}_{-18\degree}$, which is strong evidence for a nearly aligned orbit. TOI-1694b is one of fewer than ten small planets accompanied by confirmed outer giant planets for which the obliquity has been measured. We consider the significance of the outer planet TOI-1694c, a Jupiter-mass planet with a 1-year orbit, and its potential role in influencing the orbit of TOI-1694b to its current state. Incorporating our measurement, we discuss the bifurcation in hot Neptune obliquities and present evidence for an independent polar population. The observed polar planets nearly ubiquitously have periods of $\le 6$ days and mass ratios of $10^{-4}$. Early perturbations by outer companions from resonance crossings in the disk-dispersal stage provide the most compelling explanation for this population. Systems which lack the necessary configuration will retain their primordial obliquity, since hot Neptunes lack the angular momentum needed to realign their hosts on relevant timescales.
title An Obliquity Measurement of the Hot Neptune TOI-1694b
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2412.07950