J/AJ/168/81 TESS giants transiting giants. VI. Keck RVs (Saunders+, 2024)
TESS giants transiting giants.
VI. Newly discovered hot Jupiters provide evidence for efficient obliquity
Damping after the main sequence.
Saunders N., Grunblatt S.K., Chontos A., Dai F., Huber D., Zhang J.,
Stefansson G., van Saders J.L., Winn J.N., Hey D., Howard A.W., Fulton B.,
Isaacson H., Beard C., Giacalone S., Van Zandt J., Murphey J.M.A.,
Rice M., Blunt S., Turtelboom E., Dalba P.A., Lubin J., Brinkman C.,
Louden E.M., Page E., Watkins C.N., Collins K.A., Stockdale C., Tan T.-G.,
Schwarz R.P., Massey B., Howell S.B., Vanderburg A., Ricker G.R.,
Jenkins J.M., Seager S., Christiansen J.L., Daylan T., Falk B.,
Brodheim M., Gibson S.R., Hill G.M., Holden B., Householder A., Kaye S.,
Laher R.R., Lanclos K., Petigura E.A., Roy A., Rubenzahl R.A., Schwab C.,
Shaum A.P., Sirk M.M., Smith C.L., Walawender J., Yeh S.
<Astron. J., 168, 81 (2024)>
=2024AJ....168...81S 2024AJ....168...81S
ADC_Keywords: Radial velocities; Stars, masses; Stars, ages; Abundances, [Fe/H];
Rotational velocities; Exoplanets; Spectra, optical
Keywords: Exoplanet astronomy ; Exoplanet dynamics ;
Exoplanet detection methods ; Exoplanet evolution ;
Exoplanet migration ; Exoplanets ; Exoplanet systems ;
Stellar evolution ; Late stellar evolution ; Tides
Abstract:
The degree of alignment between a star's spin axis and the orbital
plane of its planets (the stellar obliquity) is related to interesting
and poorly understood processes that occur during planet formation and
evolution. Hot Jupiters orbiting hot stars (≳6250K) display a wide
range of obliquities, while similar planets orbiting cool stars are
preferentially aligned. Tidal dissipation is expected to be more rapid
in stars with thick convective envelopes, potentially explaining this
trend. Evolved stars provide an opportunity to test the damping
hypothesis, particularly stars that were hot on the main sequence and
have since cooled and developed deep convective envelopes. We present
the first systematic study of the obliquities of hot Jupiters orbiting
subgiants that recently developed convective envelopes using
Rossiter-McLaughlin observations. Our sample includes two newly
discovered systems in the Giants Transiting Giants survey (TOI-6029 b,
TOI-4379 b). We find that the orbits of hot Jupiters orbiting
subgiants that have cooled below ∼6250K are aligned or nearly aligned
with the spin axis of their host stars, indicating rapid tidal
realignment after the emergence of a stellar convective envelope. We
place an upper limit for the timescale of realignment for hot Jupiters
orbiting subgiants at ∼500Myr. Comparison with a simplified tidal
evolution model shows that obliquity damping needs to be ∼4 orders of
magnitude more efficient than orbital period decay to damp the
obliquity without destroying the planet, which is consistent with
recent predictions for tidal dissipation from inertial waves excited
by hot Jupiters on misaligned orbits.
Description:
TOI-6029 b and TOI-4379 b were discovered as part of our Giants
Transiting Giants (GTG) survey (Grunblatt+ 2022AJ....163..120G 2022AJ....163..120G,
2023AJ....165...44G 2023AJ....165...44G; Saunders+ 2022AJ....163...53S 2022AJ....163...53S and
Pereira+ 2024MNRAS.527.6332P 2024MNRAS.527.6332P). TESS data are available for TOI-6029 b
in 30-minute-cadence full-frame images (FFIs) for Sectors 17, 18, and
24, spanning from 2019 October 7 to 2020 May 13, and in 200s cadence
FFIs for Sector 58 from 2022 October 29 to November 26. It was flagged
by our survey as a planet candidate in 2021, and it was selected for
TESS 2-minute-cadence observations in Sector 58. TESS data are
available for TOI-4379 b in 30-minute FFIs in Sector 12 (2019 April
22-May 21), 10-minute cadence in Sector 39 (2021 May 26 --June 24),
and 200s cadence in Sector 66 (2023 June 2-July 1). We identified
TOI-4379 b as a planet candidate in 2021, and it received
2-minute-cadence observations in Sectors 39 and 66.
TOI-1181 b was first identified by the MIT Quick Look Pipeline (QLP;
Huang+ 2020RNAAS...4..204H 2020RNAAS...4..204H) in 2019, and TESS data are available in
30-minute-cadence FFIs for Sectors 14, 15, 17, 18, 19, 20, 21, 22, 23,
24, 25, and 26, spanning from 2019 July 18 to 2020 July 4. TESS data
are available in 10-minute-cadence FFIs for Sectors 40, 41, 47, 48,
49, 50, 51, 52, 53, 54, and 55, spanning from 2021 June 24 to 2022
September 1. In 200 s cadence FFIs, it has so far been observed in
Sectors 56, 57, 58, 59, and 60, covering 2022 Sept 1--2023 Jan 18.
TOI-1181 b was scheduled for 2-minute-cadence observations beginning
on 2020 April 16 with Sector 24, and it was selected for
2-minute-cadence data through Sector 60. See Section 2.1.
High-precision RVs were taken using the High Resolution Echelle
Spectrograph (HIRES) on the 10m Keck I telescope on Maunakea, Hawai'i;
with a spectral resolution of R∼60000. For TOI-1181 b, 87 RV
measurements were taken between 2019 December 2 and 2022 May 16. For
TOI-6029 b, 46 RV measurements were taken between 2020 December 25 and
2022 October 6. For TOI-4379 b, 12 RV measurements were taken between
2021 September 21 and 2022 July 16. See Section 2.2.
In addition to RVs over the full phase of the planets' orbits, we
obtained RV observations during each planet's transit to measure the
RM effect. We obtained high-resolution spectra during transit events
with HIRES for TOI-1181 b and TOI-6029 b and with the Keck Planet
Finder (KPF) for TOI-4379 b.
We obtained 40 HIRES RV observations during the transit of TOI-1181 b
on 2020 September 8. For TOI-6029 b, we obtained 34 HIRES RVs on 2022
September 18.
We obtained 30 observations of TOI-4379 b on 2023 June 6 using KPF,
with 9-minute exposures and R∼98000.
See Section 2.3.
We obtained high-contrast imaging of TOI-6029 and TOI-4379 to search
for close stellar companions that might have biased the measurement of
the amplitude of the transit signal observed by TESS. TOI-6029 was
observed by the NIRC2 near-infrared imager in the Kp bandpass on the
10m Keck II telescope on 2023 June 26.
TOI-4379 b was observed by the 8m Gemini South telescope on Cerro
Pachon using the speckle interferometric instrument Zorro on
2022-May-18 UT. See Section 2.4.
The TESS pixel scale is ∼21"/pixel, often causing multiple stars to
blend in the TESS photometric aperture. To confirm the true source of
the TESS detection, we acquired ground-based follow-up photometry of
the fields around TOI-6029 and TOI-4379 as part of the TESS Follow-up
Observing Program (TFOP; Collins 2019AAS...23314005C 2019AAS...23314005C).
We observed an ingress window of TOI-6029 b in Sloan band on UTC
2023 August 3 from the Las Cumbres Observatory Global Telescope
(LCOGT) 1m network node at McDonald Observatory near Fort Davis,
Texas, United States (McD). We also observed a full transit window of
TOI-4379 b in Sloan band on 2022 May 15 (UTC) from the LCOGT 1m
network node at Cerro Tololo Inter-American Observatory (CTIO) in
Chile.
We observed a full transit window of TOI-4379 b in Sloan band on
2023 May 27 (UTC) using the Perth Exoplanet Survey Telescope (PEST),
located near Perth, Australia.
See Section 2.5.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 218 3 Stellar properties derived for each of the host
stars in our sample
table3.dat 55 169 Radial velocity measurements of TOI-1181, TOI-6029,
and TOI-4379 used in our analysis
--------------------------------------------------------------------------------
See also:
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
J/ApJ/703/L99 : Outlandish orbit of HAT-P-7b (Winn+, 2009)
J/AJ/142/19 : Speckle observations of KOI (Howell+, 2011)
J/A+A/552/A120 : WASP-71b light curve (Smith+, 2013)
J/A+A/588/L6 : WASP-12 transit light curves (Maciejewski+ 2016)
J/ApJ/836/77 : High-S/N optical spectra of FGKM stars (Yee+, 2017)
J/AcA/68/371 : WASP and KELT planet transits (Maciejewski+, 2018)
J/AJ/157/192 : Radial velocities and transit times for KOI 4 (Chontos+, 2019)
J/AJ/159/280 : Gaia-Kepler stellar properties catalog. I. (Berger+, 2020)
J/ApJ/888/L5 : Transits, occultation times and RVs of WASP-12b (Yee+, 2020)
http://tess.mit.edu/followup/ : TESS Follow-up Observing Program (TFOP) home
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Name TOI star number
10 A1 --- Pl Planet ID component
12 A1 --- n_Name [a] a: Flag on TOI-1181 (1)
14- 22 I9 --- TIC [97766057/419523962] TIC star number (2)
24- 25 I2 h RAh Hour of right ascension (J2000) (2)
27- 28 I2 min RAm Minute of right ascension (J2000)
30- 34 F5.2 s RAs Second of right ascension (J2000)
36 A1 --- DE- Sign of declination (J2000) (2)
37- 38 I2 deg DEd Degree of declination (J2000) (2)
40- 41 I2 arcmin DEm Arcminute of declination (J2000)
43- 47 F5.2 arcsec DEs Arcsecond of declination (J2000)
49- 54 F6.3 mag Vmag [10.58/12.9] Johnson V magnitude (2)
56- 60 F5.3 mag e_Vmag [0.006/0.1] Uncertainty on the Vmag
62- 68 F7.4 mag Gmag [10.47/12.41] Gaia G-band magnitude (2)
70- 75 F6.4 mag e_Gmag [0.0002/0.0003] Uncertainty on the Gmag
77- 83 F7.4 mag Tmag [10.079/11.9] T band magnitude (2)
85- 90 F6.4 mag e_Tmag [0.006/0.09] Uncertainty on the Tmag
92- 95 I4 K Teff [6020/6223] Effective temperature (3)
97- 99 I3 K e_Teff [81/100] Teff uncertainty
101-104 F4.2 [Sun] [Fe/H] [0.16/0.38] Metallicity (3)
106-109 F4.2 [Sun] e_[Fe/H] [0.06] [Fe/H] uncertainty
111-114 F4.1 km/s vsini [5.9/10.6] Rotational velocity (3)
116-118 F3.1 km/s e_vsini [1] vsini uncertainty
120-124 F5.3 Msun Ms [1.37/1.55] Stellar mass (4)
126-130 F5.3 Msun e_Ms [0.02/0.11] Lower uncertainty on Ms
132-136 F5.3 Msun E_Ms [0.02/0.04] Upper uncertainty on Ms
138-142 F5.3 Rsun Rs [1.96/2.34] Stellar radius (4)
144-148 F5.3 Rsun e_Rs [0.03/0.09] Lower uncertainty on Rs
150-154 F5.3 Rsun E_Rs [0.027/0.04] Upper uncertainty on Rs
156-160 F5.3 [cm/s2] logg [3.88/4.02] Log of surface gravity (4)
162-166 F5.3 [cm/s2] e_logg [0.02/0.03] Lower uncertainty on logg
168-172 F5.3 [cm/s2] E_logg [0.016/0.04] Upper uncertainty on logg
174-177 F4.2 Gyr Age [2.3/4.51] Age (4)
179-182 F4.2 Gyr e_Age [0.19/1.21] Lower uncertainty on Age
184-187 F4.2 Gyr E_Age [0.2/0.6] Upper uncertainty on Age
189-192 F4.2 Lsun Lum [4.3/6.3] Luminosity (4)
194-197 F4.2 Lsun e_Lum [0.1/0.3] Lower uncertainty on Lum
199-202 F4.2 Lsun E_Lum [0.2/0.3] Upper uncertainty on Lum
204-208 F5.1 pc Dist [310/618] Distance (4)
210-213 F4.1 pc e_Dist [4.8/12] Lower uncertainty on Dist
215-218 F4.1 pc E_Dist [6/11.6] Upper uncertainty on Dist
--------------------------------------------------------------------------------
Note (1): Flag as follows:
a = Stellar properties (Teff, [Fe/H], vsini, Ms, Rs, logg and Age) for
TOI-1181 adopted from Chontos et al. (2024arXiv240207893C 2024arXiv240207893C)
Note (2): From TESS input catalog (Stassun+ 2019AJ....158..138S 2019AJ....158..138S)
Note (3): From SpecMatch-Synth (this work; Petigura+ 2015ApJ...811..102P 2015ApJ...811..102P)
Note (4): From isoclassify (this work; Huber 2017zndo....573372H;
Berger+ 2020, J/AJ/159/280)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.5 d BJD Time (midpoint) of observation,
Barycentric Julian date at TDB
15- 22 F8.3 m.s-1 RVel [-159/146] Radial Velocity
24- 29 F6.3 m.s-1 e_RVel [2.3/14.1] Uncertainty in RV
31- 38 A8 --- Name TOI star number
40- 49 A10 --- Inst Instrument ("Keck/HIRES" or "Keck/KPF")
51- 55 A5 --- RMcL Observation taken for Rossiter-McLaughlin effect
("False" or "True")
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Saunders et al. Paper I. 2022AJ....163...53S 2022AJ....163...53S
Grunblatt et al. Paper II. 2022AJ....163..120G 2022AJ....163..120G
Grunblatt et al. Paper III. 2023AJ....165...44G 2023AJ....165...44G
Grunblatt et al. Paper IV. 2024AJ....168....1G 2024AJ....168....1G
Pereira et al. Paper V. 2024MNRAS.527.6332P 2024MNRAS.527.6332P
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 05-Nov-2024