J/A+A/688/A223 HIP 29442 (TOI-469) CHEOPS and TESS light curves (Egger+, 2024)
Unveiling the internal structure and formation history of the three planets
transiting HIP 29442 (TOI-469) with CHEOPS.
Egger J.A., Osborn H.P., Kubyshkina D., Mordasini C., Alibert Y.,
Guenther M.N., Lendl M., Brandeker A., Heitzmann A., Leleu A., Damasso M.,
Bonfanti A., Wilson T.G., Sousa S.G., Haldemann J., Delrez L., Hooton M.J.,
Zingales T., Luque R., Alonso R., Asquier J., Barczy T.,
Barrado Navascues D., Barros S.C.C., Baumjohann W., Benz W., Billot N.,
Borsato L., Broeg C., Buder M., Castro-Gonzalez A., Collier Cameron A.,
Correia A.C.M., Cortes D., Csizmadia Sz., Cubillos P.E., Davies M.B.,
Deleuil M., Deline A., Demangeon O.D.S., Demory B.-O., Derekas A.,
Edwards B., Ehrenreich D., Erikson A., Fortier A., Fossati L., Fridlund M.,
Gandolfi D., Gazeas K., Gillon M., Guedel M., Helling Ch., Isaak K.G.,
Kiss L.L., Korth J., Lam K.W.F., Laskar J., Lavie B.,
Lecavelier des Etangs A., Lovis C., Luntzer A., Magrin D., Maxted P.F.L.,
Merin B., Munari M., Nascimbeni V., Olofsson G., Ottensamer R., Pagano I.,
Palle E., Peter G., Piazza D., Piotto G., Pollacco D., Queloz D.,
Ragazzoni R., Rando N., Rauer H., Ribas I., Rodrigues J., Santos N.C.,
Scandariato G., Segransan D., Simon A.E., Smith A.M.S., Stalport M.,
Sulis S., Szabo Gy.M., Udry S., Van Grootel V., Venturini J., Villaver E.,
Walton N.A.
<Astron. Astrophys. 688, A223 (2024)>
=2024A&A...688A.223E 2024A&A...688A.223E (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Photometry ; Optical
Keywords: techniques: photometric - planets and satellites: formation -
planets and satellites: interiors -
planets and satellites: individual: HIP 29442 - planetary systems
Abstract:
Multiplanetary systems spanning the radius valley are ideal testing
grounds for exploring the different proposed explanations for the
observed bimodality in the radius distribution of close-in exoplanets.
One such system is HIP 29442 (TOI-469), an evolved K0V star hosting
two super-Earths and one sub-Neptune. We observed HIP 29442 with
CHEOPS for a total of 9.6 days, which we modelled jointly with two
sectors of TESS data to derive planetary radii of 3.410±0.046,
1.551±0.045, and 1.538±0.049R⊕ for planets b, c, and d,
which orbit HIP 29442 with periods of 13.6, 3.5, and 6.4 days,
respectively. For planet d this value deviates by more than 3σ
from the median value reported in the discovery paper, leading us to
conclude that caution is required when using TESS photometry to
determine the radii of small planets with low per-transit
signal-to-noise ratios and large gaps between observations. Given the
high precision of these new radii, combining them with published RVs
from ESPRESSO and HIRES provides us with ideal conditions to
investigate the internal structure and formation pathways of the
planets in the system. We introduced the publicly available code
plaNETic, a fast and robust neural network-based Bayesian internal
structure modelling framework. We then applied hydrodynamic models to
explore the upper atmospheric properties of these inferred structures.
Finally, we identified planetary system analogues in a synthetic
population generated with the Bern model for planet formation and
evolution. Based on this analysis, we find that the planets likely
formed on opposing sides of the water iceline from a protoplanetary
disk with an intermediate solid mass. We finally report that the
observed parameters of the HIP 29442 system are compatible with a
scenario where the second peak in the bimodal radius distribution
corresponds to sub-Neptunes with a pure H/He envelope and with a
scenario with water-rich sub-Neptunes.
Description:
We present raw and detrended CHEOPS (extracted using PIPE) and TESS
photometry of HIP 29442 (TOI-469).
Objects:
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RA (2000) DE Designation(s)
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06 12 13.96 -14 39 00.0 HIP 29442 = TOI-469
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
cheops.dat 407 9192 CHEOPS photometry and model fits for HIP 29442
tess.dat 253 32052 TESS photometry and model fits for HIP 29442
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Byte-by-byte Description of file: cheops.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- Index Index (Index)
6- 23 F18.10 d Time BJD time (time)
25- 46 E22.16 10-3 Flux Normalised flux (in ppt unit) (flux)
48- 66 F19.17 10-3 e_Flux Normalised flux error (in ppt unit)
(flux_err)
68- 89 F22.18 deg phi Roll angle (phi)
91-108 F18.14 e- bg Background (bg)
110-127 F18.14 pix centX PSF X centroid (centroidx)
129-146 F18.14 pix centY PSF Y centroid (centroidy)
148-166 F19.15 mK deltaT Temperature change (deltaT)
168-190 E23.16 pix Xoff PSF X centroid offset (xoff)
192-215 E24.17 pix Yoff PSF Y centroid offset (yoff)
217-239 A23 --- FileKey CHEOPS file key (filekey)
241 I1 --- nphimodel Index for rollangle model (nphimodel)
243-265 E23.17 --- prspline-med Spline detrend model
(cheopspredspline_med)
267-290 E24.17 --- lindet-med Decorrelation detrend model
(cheopslindetrendmed)
292-315 E24.17 --- alldet-med Sum of detrend models
(cheopsalldetrendmed)
317-337 F21.18 --- bmod-med Planet b model (cheopsbmodelmed)
339-361 F23.20 --- cmod-med Planet c model (cheopscmodelmed)
363-383 F21.18 --- dmod-med Planet d model (cheopsdmodelmed)
385-407 F23.20 --- allplmod-med Sum of planet models
(cheopsallplmodelmed)
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Byte-by-byte Description of file: tess.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Index Index (Index)
7- 24 F18.10 d Time BJD time (time)
26- 39 E14.7 10-3 Flux Normalised flux (in ppt unit) (flux)
41- 50 F10.8 10-3 e_Flux Normalised flux error (in ppt unit)
(flux_err)
52- 55 A4 --- Mask Boolean flux mask (mask)
57- 61 A5 --- Neartrans All planet near-transit mask (near_trans)
63- 67 A5 --- intransb In-transit mask of planet b (intransb)
69- 73 A5 --- intransc In-transit mask of planet c (intransc)
75- 79 A5 --- intransd In-transit mask of planet d (intransd)
81- 85 A5 --- intransall All planet in-transit mask (intransall)
87-110 E24.17 --- spline Transit-masked flux bspline (spline)
112-134 E23.16 --- Fluxflat Spline-flattened flux (flux_flat)
136-159 E24.17 --- gpmod-med GP detrend model (tessgpmodelmed)
161-181 F21.18 --- bmod-med Planet b model (tessbmodelmed)
183-206 E24.17 --- cmod-med Planet c model (tesscmodelmed)
208-228 F21.18 --- dmod-med Planet d model (tessdmodelmed)
230-253 E24.17 --- allplmod-med Sum of planet models (tessallplmodelmed)
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Acknowledgements:
Jo Ann Egger, jo-ann.egger(at)unibe.ch
(End) Patricia Vannier [CDS] 05-Aug-2024