J/ApJ/926/L8 Spectroscopic and transit obs. of WASP-148 (Wang+, 2022)
The aligned orbit of WASP-148b, the only known hot Jupiter with a nearby warm
Jupiter companion, from NEID and HIRES.
Wang X.-Y., Rice M., Wang S., Pu B., Stefansson G., Mahadevan S.,
Radzom B., Giacalone S., Wu Z.-Y., Esposito T.M., Dalba P.A., Avsar A.,
Holden B., Skiff B., Polakis T., Voeller K., Logsdon S.E., Klusmeyer J.,
Schweiker H., Wu D.-H., Beard C., Dai F., Lubin J., Weiss L.M.,
Bender C.F., Blake C.H., Dressing C.D., Halverson S., Hearty F.,
Howard A.W., Huber D., Isaacson H., Jackman J.A.G., Llama J.,
McElwain M.W., Rajagopal J., Roy A., Robertson P., Schwab C.,
Shkolnik E.L., Wright J.T., Laughlin G.
<Astrophys. J., 926, L8 (2022)>
=2022ApJ...926L...8W 2022ApJ...926L...8W
ADC_Keywords: Spectra, optical; Radial velocities; Photometry; Exoplanets
Keywords: Planetary alignment ; Exoplanet dynamics ; Star-planet interactions ;
Exoplanets ; Planetary theory ; Exoplanet systems
Abstract:
We present spectroscopic measurements of the Rossiter-McLaughlin
effect for WASP-148b, the only known hot Jupiter with a nearby
warm-Jupiter companion, from the WIYN/NEID and Keck/HIRES instruments.
This is one of the first scientific results reported from the newly
commissioned NEID spectrograph, as well as the second obliquity
constraint for a hot Jupiter system with a close-in companion, after
WASP-47. WASP-148b is consistent with being in alignment with the
sky-projected spin axis of the host star, with
λ=-8.2°-9.7+8.7. The low obliquity observed in the
WASP-148 system is consistent with the orderly-alignment configuration
of most compact multi-planet systems around cool stars with obliquity
constraints, including our solar system, and may point to an early
history for these well-organized systems in which migration and
accretion occurred in isolation, with relatively little disturbance.
By contrast, previous results have indicated that high-mass and hot
stars appear to more commonly host a wide range of misaligned planets:
not only single hot Jupiters, but also compact systems with multiple
super-Earths. We suggest that, to account for the high rate of
spin-orbit misalignments in both compact multi-planet and
isolated-hot-Jupiter systems orbiting high-mass and hot stars,
spin-orbit misalignments may be caused by distant giant planet
perturbers, which are most common around these stellar types.
Description:
We observed WASP-148 with the high-resolution (R∼110000) WIYN/NEID
spectrograph on 2021 April 26 and obtained 24 RV measurements with
fixed, 900s exposure times from UT 5:07-11:40. See Section 2.1.1.
We also obtained 38 RV measurements of WASP-148 with continuous
Keck/HIRES observations from UT6:14-14:38 on 2021 June 9. All
Keck/HIRES observations were obtained with the C2 decker (14"x0.861",
R=60000). During June 11, we also obtained a 45-minute iodine-free
HIRES template spectrum of WASP-148 using the B3 decker (14.0"x0.574",
R=72000). See Section 2.1.2.
To directly measure the transit mid-time, we took photometric
observations of WASP-148 using the 42-inch Hall telescope and 1-m
Planewave telescope at Lowell Observatory; the 1-m Nickel telescope at
Lick Observatory; and an array of seven 4.5-inch Unistellar eVscopes
located in California and North Carolina while simultaneously
observing the R-M effect with Keck/HIRES. The obtained light curves
are provided in Figure 2.
In addition to the simultaneous photometric observations, our analysis
also incorporates two photometric transits obtained with the 1.5-m
Ritchey-Chretien Telescope as well as TESS light curves derived from
the MIT QuickLook Pipeline. Seven transits of WASP-148b were observed
in TESS Sectors 24-26 from 2020 April 16 to July 04, with 30 minute
exposures.
See Section 2.2.
Objects:
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RA (ICRS) DE Designation(s) (Per, b)
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16 56 31.33 +44 18 09.5 WASP-148 = Gaia DR3 1358355738906114816 (Pb=8.803)
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
rv.dat 35 77 Spectroscopic radial velocities of WASP-148
(Data behind Figure 1)
lc.dat 44 1424 Photometric transit observations of WASP-148
(Data behind Figure 2)
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See also:
J/ApJS/159/141 : Spectroscopic properties of cool stars. I. (Valenti+, 2005)
J/ApJ/707/446 : HAT-P-13 photometry follow-up (Bakos+, 2009)
J/ApJ/757/18 : Rvels for 16 hot Jupiter host stars (Albrecht+, 2012)
J/MNRAS/436/1883 : Properties of KOI host stars (Walkowicz+, 2013)
J/ApJ/792/L31 : HARPS and HARPS-N 55 Cnc Rvels (Lopez-Morales+, 2014)
J/ApJ/808/16 : Cannon: a new approach to determine abundances (Ness+, 2015)
J/ApJ/834/17 : Mass & radius of planets & low mass stars (Chen+, 2017)
J/AJ/155/255 : Rvel and activity measurements of HAT-P-11 (Yee+, 2018)
J/AJ/157/52 : Radial velocity obs. in super-Earth systems (Bryan+, 2019)
J/A+A/640/A32 : WASP-148 velocity curve (Hebrard+, 2020)
J/AcA/70/203 : WASP-148 Ground-based Phot. Obs. (Maciejewski+, 2020)
J/ApJ/898/119 : Archival Keck HIRES sp. analyzed with Cannon (Rice+, 2020)
J/AJ/159/100 : Flux & RVs of G9-40 with K2 & HPF (Stefansson+, 2020)
J/AJ/161/68 : Obliquities of 150 hot Kepler hosting stars (Louden+, 2021)
J/AJ/162/89 : HIRES Rvel follow up for Kepler-129 (Zhang+, 2021)
Byte-by-byte Description of file: rv.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 F14.6 d BJD Barcentric Julian Date; TBD
16- 23 F8.2 m/s RVel [-5651/15] Radial velocity
25- 29 F5.2 m/s e_RVel [1.5/12] Internal uncertainty in RVel
31- 35 A5 --- Inst Instrument used ("HIRES", "NEID")
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Byte-by-byte Description of file: lc.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 F14.6 d BJD Barcentric Julian Date; TBD
16- 22 F7.5 m/s NFlux [0.97/1.01] Normalized flux
24- 30 F7.5 m/s e_NFlux [0.0008/0.013] Uncertainty in NFlux
32- 44 A13 --- Inst Instrument used (1)
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Note (1): Instrument as follows:
42-inch Hall = the 42-inch Hall telescope at Lowell Observatory
(967 occurrences)
1-m Planewave = the 1-m Planewave telescope at Lowell Observatory
(378 occurrences)
1m Nickel = the 1-m Nickel telescope at Lick Observatory (46 occurrences)
Unistellar = an array of seven 4.5-inch Unistellar eVscopes located in
California and North Carolina (33 occurrences)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Nov-2023