J/A+A/691/A233 TOI-5005 b phot. and radial velocities (Castro-Gonzalez+, 2024)
TOI-5005 b: A super-Neptune in the savanna near the ridge.
Castro-Gonzalez A., Lillo-Box J., Armstrong D.J., Acuna L., Aguichine A.,
Bourrier V., Gandhi S., Sousa S.G., Delgado-Mena E., Moya A., Adibekyan V.,
Correia A.C.M., Barrado D., Damasso M., Winn J.N., Santos N.C., Bakaoui K.,
Barros S.C.C., Benkhaldoun Z., Bouchy F., Briceno C., Caldwell D.A.,
Collins K.A., Essack Z., Ghachoui M., Gillon M., Hounsell R., Jehin E.,
Jenkins J.M., Keniger M.A.F., Law N., Mann A.W., Nielsen L.D.,
Pozuelos F.J., Schanche N., Seager S., Tan T.-G., Timmermans M.,
Villasenor J., Watkins C.N., Ziegler C.
<Astron. Astrophys. 691, A233 (2024)>
=2024A&A...691A.233C 2024A&A...691A.233C (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Photometry ; Optical ;
Radial velocities
Keywords: techniques: photometric - techniques: radial velocities -
planets and satellites: composition -
planets and satellites: detection -
planets and satellites: individual: TOI-5005 b -
stars: individual: TOI 5005 (TIC 282485660)
Abstract:
The Neptunian desert and savanna have been recently found to be
separated by a ridge, an overdensity of planets in the ∼3-5 days
period range. These features are thought to be shaped by dynamical and
atmospheric processes. However, their relative roles are not yet well
understood. We intend to confirm and characterise the super-Neptune
TESS candidate TOI-5005.01, which orbits a moderately bright (V=11.8)
solar-type star (G2 V) with an orbital period of 6.3 days. With such
properties, TOI-5005.01 is located in the Neptunian savanna near the
ridge. We used Bayesian inference to analyze 38 HARPS radial velocity
measurements, three sectors of TESS photometry, and two PEST and
TRAPPIST-South transits. We tested a set of models involving eccentric
and circular orbits, long-term drifts, and Gaussian processes to
account for correlated stellar and instrumental noise. We computed the
Bayesian evidences to find the model that best represents our data set
and infer the orbital and physical properties of the system. We
confirm TOI-5005∼b to be a transiting super-Neptune with a radius of
Rp=6.25±0.24R⊕ (Rp=0.558±0.021RJup) and a mass of
Mp=32.7±5.9M_⊕ (Mp=0.103±0.018MJup_), which corresponds
to a mean density of rhop=0.74±0.16g/cm3. Our internal structure
modelling indicates that the core mass fraction
(CMF=0.74+0.05-0.45) and envelope metal mass fraction
(Zenv=0.08+0.41-0.06) of TOI-5005 b are degenerate, but the
overall metal mass fraction is well constrained to a value slightly
lower than that of Neptune and Uranus (Zplanet=0.76+0.04-0.11).
The Zplanet/Zstar ratio is consistent with the well-known
mass-metallicity relation, which suggests that TOI-5005∼b was formed
via core accretion. We also estimated the present-day atmospheric
mass-loss rate of TOI-5005 b but found contrasting predictions
depending on the choice of photoevaporation model
(0.013±0.008M⊕/Gyr versus 0.17±0.12M⊕/Gyr). At a
population level, we find statistical evidence (p-value
=0.0092+0.0184-0.0066) that planets in the savanna such as
TOI-5005 b tend to show lower densities than planets in the ridge,
with a dividing line around 1g/cm-3, which supports the hypothesis
of different evolutionary pathways populating both regimes. TOI-5005 b
is located in a key region of the period-radius space to study the
transition between the Neptunian ridge and the savanna. It orbits the
brightest star of all such planets known today, which makes it a
target of interest for atmospheric and orbital architecture
observations that will bring a clearer picture of its overall
evolution.
Description:
Photometry and radial velocities used to confirm the planetary nature
of TOI-5005 b.
Objects:
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RA (2000) DE Designation(s)
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15 52 26.0 -48 08 42.4 TOI-5005 = TIC 282485660
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablec1.dat 66 22829 TESS Simple Aperture Photometry (SAP) of
TOI-5005 (Sectors 12, 39, and 65)
tablec2.dat 66 22207 TESS QLP (Sector 12) and PDCSAP (Sectors 39 and
65) photometry of TOI-5005
tablec3.dat 103 257 PEST photometry of TOI-5005 corresponding to a
transit of TOI-5005 b
tablec4.dat 194 414 TRAPPIST-South photometry of TOI-5005
corresponding to a transit of TOI-5005 b
tablec5.dat 132 38 HARPS radial velocities of TOI-5005 obtained
under the programs 108.21YY.001 and
108.21YY.002 (PI: Armstrong)
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Byte-by-byte Description of file: tablec1.dat
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Bytes Format Units Label Explanations
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1- 18 F18.10 d BJD Baricentric Julian date
20- 37 F18.16 --- SAP TESS Simple Aperture Photometry (SAP)
normalized flux
39- 59 F21.19 --- e_SAP TESS Simple Aperture Photometry (SAP)
normalized flux error
61- 66 A6 --- Sector TESS Sector
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Byte-by-byte Description of file: tablec2.dat
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Bytes Format Units Label Explanations
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1- 18 F18.10 d BJD Baricentric Julian date
20- 37 F18.16 --- QLP/PDCSAP ? TESS QLP (Sector 12) and PDCSAP
(Sectors 39 and 65) normalized flux
39- 59 F21.19 --- e_QLP/PDCSAP TESS QLP (Sector 12) and PDCSAP
(Sectors 39 and 65) normalized flux error
61- 66 A6 --- Sector TESS Sector
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Byte-by-byte Description of file: tablec3.dat
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Bytes Format Units Label Explanations
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1- 15 F15.7 d BJD Baricentric Julian date (TDB)
17- 22 F6.4 --- Flux PEST normalized flux
24- 29 F6.4 --- e_Flux PEST normalized flux error
31- 36 F6.4 --- VarFlux Normalised PEST flux so that its mean is 1
38- 43 F6.4 --- CompFlux Normalized PEST flux of a comparison field
star so that its mean is 1
45- 53 F9.4 --- Xcoord X coordinate of the target in the CCD
55- 62 F8.4 --- Ycoord Y coordinate of the target in the CCD
64- 71 F8.4 --- DistCenter Distance to the center of the CCD
73- 78 F6.4 --- FWHM Full width at half maximum (FWHM) of the
Point Spread Function (PSF)
80- 85 F6.4 --- AirMass Airmass
87- 95 F9.4 --- Sky Background flux
97-103 F7.4 --- ENSavg Average ENS
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Byte-by-byte Description of file: tablec4.dat
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Bytes Format Units Label Explanations
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1- 18 F18.10 d BJD Baricentric Julian date (TDB)
20- 37 F18.16 --- dFlux TRAPPIST-South differential flux
39- 56 F18.16 --- e_dFlux TRAPPIST-South differential flux error
58- 78 F21.16 --- dXmove Displacement of the target in the CCD
across the X axis
80- 99 F20.16 --- dYmove Displacement of the target in the CCD
across the Y axis
101-118 F18.16 --- FWHM Full width at half maximum (FWHM) of the
Point Spread Function (PSF)
120-137 F18.16 --- FWHMX Full width at half maximum (FWHM) of the
Point Spread Function (PSF) across the X axis
139-156 F18.16 --- FWHMY Full width at half maximum (FWHM) of the
Point Spread Function (PSF) across the Y axis
158-175 F18.14 --- SkyLevel Background flux
177-189 F13.11 --- AirMass Airmass
191-194 F4.1 s ExpTime Exposure time
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Byte-by-byte Description of file: tablec5.dat
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Bytes Format Units Label Explanations
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1- 18 F18.12 d JD Reduced Julian date (JD-2400000)
20- 31 F12.6 m/s RV Radial velocity
33- 40 F8.6 m/s e_RV Radial velocity error
42- 52 F11.6 m/s FWHM Full width at half maximum (FWHM) of the
cross-correlation function (CCF)
54- 62 F9.6 m/s e_FWHM Error of the full width at half maximum (FWHM)
of the cross-correlation function (CCF)
64- 71 F8.6 --- SMW S-index
73- 80 F8.6 --- e_SMW S-index error
82- 89 F8.6 --- Ca Calcium line depth
91- 98 F8.6 --- e_Ca Calcium line depth error
100-107 F8.6 --- Ha Hα line depth
109-116 F8.6 --- e_Ha Hα line depth error
118-126 F9.6 % Contrast Contrast of the cross-correlation function
(CCF)
128-132 E5.1 % e_Contrast Error of the contrast of the cross-correlation
function (CCF)
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Acknowledgements:
Amadeo Castro-Gonzalez, acastro(at)cab.inta-csic.es
(End) Amadeo Castro-Gonzalez [CAB, Spain], Patricia Vannier [CDS] 14-Oct-2024