Orbital orientations of exoplanets: HAT-P-4b is prograde and HAT-P-14b is retrograde

Joshua N. Winn; Andrew W. Howard; John Asher Johnson; Geoffrey W. Marcy; Howard Isaacson; Avi Shporer; Gáspár Á Bakos; Joel D. Hartman; Matthew J. Holman; Simon Albrecht; Justin R. Crepp; Timothy D. Morton

doi:10.1088/0004-6256/141/2/63

Orbital orientations of exoplanets: HAT-P-4b is prograde and HAT-P-14b is retrograde

Joshua N. Winn, Andrew W. Howard, John Asher Johnson, Geoffrey W. Marcy, Howard Isaacson, Avi Shporer, Gáspár Á Bakos, Joel D. Hartman, Matthew J. Holman, Simon Albrecht, Justin R. Crepp, Timothy D. Morton

Research output: Contribution to journal › Article › peer-review

23 Scopus citations

Abstract

We present observations of the Rossiter-McLaughlin effect for two exoplanetary systems, revealing the orientations of their orbits relative to the rotation axes of their parent stars. HAT-P-4b is prograde, with a sky-projected spin-orbit angle of λ = -4.9 ± 11.9 deg. In contrast, HAT-P-14b is retrograde, with λ = 189.1 ± 5.1 deg. These results conform with a previously noted pattern among the stellar hosts of close-in giant planets: hotter stars have a wide range of obliquities and cooler stars have low obliquities. This, in turn, suggests that three-body dynamics and tidal dissipation are responsible for the short-period orbits of many exoplanets. In addition, our data revealed a third body in the HAT-P-4 system, which could be a second planet or a companion star.

Original language	English (US)
Journal	Astronomical Journal
Volume	141
Issue number	2
DOIs	https://doi.org/10.1088/0004-6256/141/2/63
State	Published - Feb 2011
Externally published	Yes

All Science Journal Classification (ASJC) codes

Astronomy and Astrophysics
Space and Planetary Science

Keywords

Planet-star interactions
Planetary systems
Planets and satellites: Formation
Stars: Rotation

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10.1088/0004-6256/141/2/63

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title = "Orbital orientations of exoplanets: HAT-P-4b is prograde and HAT-P-14b is retrograde",

abstract = "We present observations of the Rossiter-McLaughlin effect for two exoplanetary systems, revealing the orientations of their orbits relative to the rotation axes of their parent stars. HAT-P-4b is prograde, with a sky-projected spin-orbit angle of λ = -4.9 ± 11.9 deg. In contrast, HAT-P-14b is retrograde, with λ = 189.1 ± 5.1 deg. These results conform with a previously noted pattern among the stellar hosts of close-in giant planets: hotter stars have a wide range of obliquities and cooler stars have low obliquities. This, in turn, suggests that three-body dynamics and tidal dissipation are responsible for the short-period orbits of many exoplanets. In addition, our data revealed a third body in the HAT-P-4 system, which could be a second planet or a companion star.",

keywords = "Planet-star interactions, Planetary systems, Planets and satellites: Formation, Stars: Rotation",

author = "Winn, {Joshua N.} and Howard, {Andrew W.} and Johnson, {John Asher} and Marcy, {Geoffrey W.} and Howard Isaacson and Avi Shporer and Bakos, {G{\'a}sp{\'a}r {\'A}} and Hartman, {Joel D.} and Holman, {Matthew J.} and Simon Albrecht and Crepp, {Justin R.} and Morton, {Timothy D.}",

year = "2011",

month = feb,

doi = "10.1088/0004-6256/141/2/63",

language = "English (US)",

volume = "141",

journal = "Astronomical Journal",

issn = "0004-6256",

publisher = "American Astronomical Society",

number = "2",

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TY - JOUR

T1 - Orbital orientations of exoplanets

T2 - HAT-P-4b is prograde and HAT-P-14b is retrograde

AU - Winn, Joshua N.

AU - Howard, Andrew W.

AU - Johnson, John Asher

AU - Marcy, Geoffrey W.

AU - Isaacson, Howard

AU - Shporer, Avi

AU - Bakos, Gáspár Á

AU - Hartman, Joel D.

AU - Holman, Matthew J.

AU - Albrecht, Simon

AU - Crepp, Justin R.

AU - Morton, Timothy D.

PY - 2011/2

Y1 - 2011/2

N2 - We present observations of the Rossiter-McLaughlin effect for two exoplanetary systems, revealing the orientations of their orbits relative to the rotation axes of their parent stars. HAT-P-4b is prograde, with a sky-projected spin-orbit angle of λ = -4.9 ± 11.9 deg. In contrast, HAT-P-14b is retrograde, with λ = 189.1 ± 5.1 deg. These results conform with a previously noted pattern among the stellar hosts of close-in giant planets: hotter stars have a wide range of obliquities and cooler stars have low obliquities. This, in turn, suggests that three-body dynamics and tidal dissipation are responsible for the short-period orbits of many exoplanets. In addition, our data revealed a third body in the HAT-P-4 system, which could be a second planet or a companion star.

AB - We present observations of the Rossiter-McLaughlin effect for two exoplanetary systems, revealing the orientations of their orbits relative to the rotation axes of their parent stars. HAT-P-4b is prograde, with a sky-projected spin-orbit angle of λ = -4.9 ± 11.9 deg. In contrast, HAT-P-14b is retrograde, with λ = 189.1 ± 5.1 deg. These results conform with a previously noted pattern among the stellar hosts of close-in giant planets: hotter stars have a wide range of obliquities and cooler stars have low obliquities. This, in turn, suggests that three-body dynamics and tidal dissipation are responsible for the short-period orbits of many exoplanets. In addition, our data revealed a third body in the HAT-P-4 system, which could be a second planet or a companion star.

KW - Planet-star interactions

KW - Planetary systems

KW - Planets and satellites: Formation

KW - Stars: Rotation

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DO - 10.1088/0004-6256/141/2/63

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JO - Astronomical Journal

JF - Astronomical Journal

IS - 2

ER -

Orbital orientations of exoplanets: HAT-P-4b is prograde and HAT-P-14b is retrograde

Abstract

All Science Journal Classification (ASJC) codes

Keywords

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