Issue |
A&A
Volume 690, October 2024
|
|
---|---|---|
Article Number | A235 | |
Number of page(s) | 27 | |
Section | Planets and planetary systems | |
DOI | https://doi.org/10.1051/0004-6361/202450366 | |
Published online | 11 October 2024 |
The GAPS Programme at TNG
LIX. Characterisation study of the ∼300 Myr-old multi-planetary system orbiting the star BD+40 2790 (TOI-2076)★
1
INAF – Osservatorio Astrofisico di Torino,
Via Osservatorio 20,
10025
Pino Torinese,
Italy
2
INAF – Osservatorio Astronomico di Palermo,
Piazza del Parlamento 1,
90134
Palermo,
Italy
3
ESO – European Southern Observatory,
Alonso de Cordova 3107, Vitacura,
Santiago,
Chile
4
INAF – Osservatorio Astronomico di Padova,
Vicolo dell’Osservatorio 5,
35122
Padova,
Italy
5
INAF – Osservatorio Astronomico di Roma,
Via Frascati 33,
00078
Monte Porzio Catone (Roma),
Italy
6
Instituto de Astrofísica de Canarias (IAC),
Calle Vía Láctea s/n,
38200
La Laguna,
Tenerife,
Spain
7
Departamento de Astrofísica, Universidad de La Laguna (ULL),
38206
La Laguna,
Tenerife,
Spain
8
Department of Astronomy, Indiana University,
Bloomington,
IN
47405,
USA
9
Dipartimento di Fisica e Astronomia “G. Galilei” – Università degli Studi di Padova,
Vicolo dell’Osservatorio 3,
35122
Padova,
Italy
10
INAF – Osservatorio Astrofisico di Catania,
Via S. Sofia 78,
95123
Catania,
Italy
11
Institute of Astronomy, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University,
Grudzia̧dzka 5,
87–100
Toruń,
Poland
12
INAF – Osservatorio Astronomico di Trieste,
via Tiepolo 11,
34143
Trieste,
Italy
13
INAF – Osservatorio Astronomico di Brera,
Via E. Bianchi 46,
23807
Merate (LC),
Italy
14
Fundación Galileo Galilei-INAF,
Rambla José Ana Fernández Pérez 7,
38712
Breña Baja,
Spain
15
Dipartimento di Fisica, Università di Roma “Tor Vergata”,
Via della Ricerca Scientifica 1,
00133
Rome,
Italy
16
Dipartimento di Fisica, Sapienza Università di Roma,
Piazzale Aldo Moro 5,
00185
Roma,
Italy
17
Max Planck Institute for Astronomy,
Königstuhl 17,
69117
Heidelberg,
Germany
18
Centro de Astrobiología CSIC-INTA,
Carretera de Ajalvir km 4,
28850 Torrejón de Ardoz,
Madrid,
Spain
★★ Corresponding author; mario.damasso@inaf.it
Received:
14
April
2024
Accepted:
8
August
2024
Context. The long-term Global Architecture of Planetary Systems (GAPS) programme has been characterising a sample of young systems with transiting planets via spectroscopic and photometric follow-up observations. One of the main goals of GAPS is measuring planets’ dynamical masses and bulk densities to help build a picture of how planets evolve in the early stages of their formation via a comparison between the fundamental physical properties of young and mature exoplanets.
Aims. We collected more than 300 high-resolution spectra of the ∼300 Myr old star BD+40 2790 (TOI-2076) over about three years. This star hosts three transiting planets discovered by TESS, with orbital periods of ∼10, 21, and 35 days. From our determined fundamental planetary physical properties, we investigate the temporal evolution of the planetary atmospheres by calculating the expected mass loss rate due to photo-evaporation up to a system age of 5 Gyr.
Methods. BD+40 2790 shows an activity-induced scatter larger than 30 m s−1 in the radial velocities. We employed different methods to measure the stellar radial velocities, along with several models to filter out the dominant stellar activity signal to bring to light the planet-induced signals, which are expected to have semi-amplitudes that are lower by one order of magnitude. We evaluated the mass loss rate of the planetary atmospheres using photo-ionisation hydrodynamic modeling, accounting for the temporal evolution of the stellar high-energy flux through the adoption of different models for X-rays and EUV irradiation.
Results. The dynamical analysis confirms that the three sub-Neptune-sized companions (with our radius measurements of Rb = 2.54±0.04, Rc = 3.35±0.05, and Rd = 3.29±0.06 R⊕) have masses that situate them in the planetary regime. We derived 3σ upper limits below or close to the mass of Neptune for all the planets in our sample: 11–12, 12–13.5, and 14–19 M⊕for planets b, c, and d, respectively. In the case of planet d, we found promising clues that the mass could be between ∼7 and 8 M⊕, with a significance level between 2.3–2.5σ (at best). This result must be further investigated using other analysis methods and techniques or using high-precision near-infrared (nIR) spectrographs to collect new radial velocities, which could be less affected by stellar activity. Atmospheric photoevaporation simulations predict that BD+40 2790 b is currently losing its H-He gaseous envelope and that it will be completely lost at an age within 0.5–3 Gyr if its current mass is lower than 12M⊕. Furthermore, BD+40 2790 c could have a lower bulk density than b and might be able to retain its atmosphere up to an age of 5 Gyr. For the outermost object, planet d, we predicted an almost negligible evolution of its mass and radius, induced by photo-evaporation.
Key words: techniques: photometric / techniques: radial velocities / planets and satellites: general / stars: individual: BD+40 2790
Based on observations made with i) the Italian Telescopio Nazionale Galileo (TNG) operated by the Fundación Galileo Galilei (FGG) of the Istituto Nazionale di Astrofisica (INAF) at (i) the Observatorio del Roque de los Muchachos (La Palma, Canary Islands, Spain); (ii) the Spanish 3.5 m telescope at Calar Alto Observatory (Almería, Spain); (iii) the US WIYN 3.5 m telescope at Kitt Peak National Observatory (Tucson, Arizona).
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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