A compact multi-planet system transiting HIP 29442 (TOI-469) discovered by TESS and ESPRESSO Radial velocities lead to the detection of transits with low signal-to-noise ratio

被引：9

作者：

Damasso, M. ^{[1
]}

Rodrigues, J. ^{[2
,3
]}

Castro-Gonzalez, A. ^{[4
]}

Lavie, B. ^{[5
]}

Davoult, J. ^{[6
,7
]}

Osorio, M. R. Zapatero ^{[8
]}

Dou, J. ^{[9
]}

Sousa, S. G. ^{[2
]}

Owen, J. E. ^{[10
]}

Sossi, P. ^{[11
]}

Adibekyan, V. ^{[2
,3
]}

Osborn, H. ^{[6
,7
]}

Leinhardt, Z. ^{[8
]}

Alibert, Y. ^{[6
,7
]}

Lovis, C. ^{[5
]}

Mena, E. Delgado ^{[2
]}

Sozzetti, A. ^{[1
]}

Barros, S. C. C. ^{[2
,3
]}

Bossini, D. ^{[2
]}

Ziegler, C. ^{[12
]}

Ciardi, D. R. ^{[13
]}

Matthews, E. C. ^{[14
]}

Carter, P. J. ^{[8
]}

Lillo-Box, J. ^{[4
]}

Mascareno, A. Suarez ^{[15
,16
]}

Cristiani, S. ^{[17
,18
]}

Pepe, F. ^{[4
]}

Rebolo, R. ^{[15
,16
,19
]}

Santos, N. C. ^{[2
,3
]}

Prieto, C. Allende ^{[15
,16
]}

Benatti, S. ^{[20
]}

Bouchy, F. ^{[4
]}

Briceno, C. ^{[21
]}

Di Marcantonio, P. ^{[17
]}

D'Odorico, V. ^{[17
,18
]}

Dumusque, X. ^{[4
]}

Egger, J. A. ^{[6
,7
]}

Ehrenreich, D. ^{[4
]}

Faria, J. ^{[2
,3
]}

Figueira, P. ^{[2
,5
]}

Santos, R. Genova ^{[15
,16
]}

Gonzales, E. J. ^{[22
]}

Hernandez, J. I. Gonzalez ^{[15
,16
]}

Law, N. ^{[23
]}

Lo Curto, G. ^{[24
]}

Mann, A. W. ^{[23
]}

Martins, C. J. A. P. ^{[2
,25
]}

Mehner, A. ^{[24
]}

Micela, G. ^{[20
]}

Molaro, P. ^{[17
]}

机构：

[1] INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy

[2] Univ Porto, Inst Astrofis & Ciencias Espaco, CAUP, Rua Estrelas, P-4150762 Porto, Portugal

[3] Univ Porto, Fac Ciencias, Dept Fis & Astron, Rua Campo Alegre, P-4169007 Porto, Portugal

[4] CSIC INTA, Ctr Astrobiol CAB, Dept Astrofis, ESAC Campus, Villanueva De La Canada 28692, Madrid, Spain

[5] Univ Geneva, Dept Astron, Chemin Pegasi 51, CH-1290 Versoix, Switzerland

[6] Univ Bern, Ctr Space & Habitabil, Gesell Str 6, CH-3012 Bern, Switzerland

[7] Univ Bern, Phys Inst, Gesell Str 6, CH-3012 Bern, Switzerland

[8] CSIC INTA, Ctr Astrobiol, Carretera Ajalvir Km 4, Torrejon De Ardoz 28850, Madrid, Spain

[9] Univ Bristol, Sch Phys, HH Wills Phys Lab, Tyndall Ave, Bristol BS8 1TL, England

[10] Imperial Coll London, Dept Phys, Astrophys Grp, Prince Consort Rd, London SW7 2AZ, England

[11] Swiss Fed Inst Technol, Inst Geochem & Petrol, Clausiusstr 25, CH-8092 Zurich, Switzerland

[12] Stephen F Austin State Univ, Dept Phys Engn & Astron, 1936 North St, Nacogdoches, TX 75962 USA

[13] Caltech IPAC, NASA Exoplanet Sci Inst, 1200 East Calif Blvd, Pasadena, CA 91125 USA

[14] Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany

[15] Inst Astrofis Canarias, Via Lactea, San Cristobal la Laguna 38200, Tenerife, Spain

[16] Univ La Laguna, Dept Fis, Avda Astrofis Francisco Sanchez S-N, San Cristobal la Laguna 38206, Tenerife, Spain

[17] INAF Osservatorio Astron Trieste, Via Tiepolo 11, I-34143 Trieste, Italy

[18] IFPU, Inst Fundamental Phys Universe, Via Beirut 2, I-34151 Trieste, Italy

[19] CSIC, C Serrano 119, Madrid 28006, Spain

[20] INAF Osservatorio Astron Palermo, Piazza Parlamento 1, I-90134 Palermo, Italy

[21] NSFs NOIRLab, Cerro Tololo Interamer Observ, Casilla 603, La Serena, Chile

[22] Univ Calif Santa Cruz, Dept Astron & Astrophys, 1156 High St, Santa Cruz, CA 95064 USA

[23] Univ North Carolina Chapel Hill, Dept Phys & Astron, 120 E Cameron Ave,Phillips Hall CB3255, Chapel Hill, NC 27599 USA

[24] European Southern Observ, ESO, Alonso de Cordova 3107, Santiago, Chile

[25] Univ Porto, Ctr Astrofis, Rua Estrelas, P-4150762 Porto, Portugal

[26] Univ Lisbon, Inst Astrofis & Ciencias Espaco, Fac Ciencias, PT-1749016 Lisbon, Portugal

[27] INAF Osservatorio Astron Brera, Via Bianchi 46, I-23807 Merate, Italy

[28] NASA Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA

来源：

ASTRONOMY & ASTROPHYSICS | 2023年 / 679卷

基金：

欧洲研究理事会; 瑞士国家科学基金会;

关键词：

stars: individual: HIP29442; stars: individual: TOI-469; planetary systems; techniques: photometric; techniques: radial velocities; planets and satellites: interiors; POWERED MASS-LOSS; MINI-NEPTUNE; SUPER-EARTHS; ELEMENTAL ABUNDANCE; EXTRASOLAR PLANETS; ERROR-CORRECTION; SHORT-PERIOD; F-DWARF; STELLAR; KEPLER;

D O I：

10.1051/0004-6361/202347240

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Context. One of the goals of the Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations (ESPRESSO) Guaranteed Time Observations (GTO) consortium is the precise characterisation of a selected sample of planetary systems discovered by TESS. One such target is the K0V star HIP 29442 (TOI-469), already known to host a validated sub-Neptune companion TOI-469.01, which we followed-up with ESPRESSO.Aims. We aim to verify the planetary nature of TOI-469.01 by obtaining precise mass, radius, and ephemeris, and constraining its bulk physical structure and composition.Methods. Following a Bayesian approach, we modelled radial velocity and photometric time series to measure the dynamical mass, radius, and ephemeris, and to characterise the internal structure and composition of TOI-469.01.Results. We confirmed the planetary nature of TOI-469.01 (now renamed HIP 29442 b), and thanks to the ESPRESSO radial velocities we discovered two additional close-in companions. Through an in-depth analysis of the TESS light curve, we could also detect their low signal-to-noise transit signals. We characterised the additional companions, and conclude that HIP 29442 is a compact multi-planet system. The three planets have orbital periods P-orb,P- b = 13.63083 +/- 0.00003, P-orb,P- c = 3.53796 +/- 0.00003, and (Porb, d) = 6.42975+0.00009 -0.00010 days, and we measured their masses with high precision: m(p, b) = 9.6 +/- 0.8 M-circle plus, m(p, c) = 4.5 +/- 0.3 M-circle plus, and m(p, d) = 5.1 +/- 0.4 M-circle plus. We measured radii and bulk densities of all the planets (the 3 sigma confidence intervals are shown in parentheses): R-p,R- b = 3.48(-0.08 (-0.28))(+0.07(+0.19)) R-circle plus and rho(p, b) = 1.3 +/- 0.2 (0.3) g cm(-3); R-p,R- c = (1.58+0.10(+0.30))(-0.11(-0.34)) R-circle plus and rho(p, c) = 6.3(-1.3(-2.7))(+1.7(+6.0)) g cm(-3); R-p,R- d = 1.37 +/- 0.11((-0.43))((+0.32)) R-circle plus and rho(p, d) = 11.0(-2.4(-6.3))(+3.4(+21.0)) g cm(-3). Due to noisy light curves, we used the more conservative 3 sigma confidence intervals for the radii as input to the interior structure modelling. We find that HIP 29442 b appears as a typical sub-Neptune, likely surrounded by a gas layer of pure H-He with a mass of 0.27(-0.17)(+0.24) M-circle plus and a thickness of 1.4 +/- 0.5 R-circle plus. For the innermost companions HIP 29442 c and HIP 29442 d, the model an Earth-like composition.Conclusions. The compact multi-planet system orbiting HIP 29442 offers the opportunity to study simultaneously planets straddling the gap in the observed radius distribution of close-in small-size exoplanets. High-precision photometric follow-up is required to obtain more accurate and precise radius measurements, especially for planets c and d. This, together with our determined high-precision masses, will provide the accurate and precise bulk structure of the planets, and enable an accurate investigation of the system's evolution.

引用

页数：22