Uncovering the true periods of the young sub-Neptunes orbiting TOI-2076
(2022) In Astronomy and Astrophysics 664.- Abstract
- Context. TOI-2076 is a transiting three-planet system of sub-Neptunes orbiting a bright (G = 8.9 mag), young (340 ±80 Myr) K-type star. Although a validated planetary system, the orbits of the two outer planets were unconstrained as only two non-consecutive transits were seen in TESS photometry. This left 11 and 7 possible period aliases for each. Aims. To reveal the true orbits of these two long-period planets, precise photometry targeted on the highest-probability period aliases is required. Long-term monitoring of transits in multi-planet systems can also help constrain planetary masses through TTV measurements. Methods. We used the MonoTools package to determine which aliases to follow, and then performed space-based and ground-based... (More)
- Context. TOI-2076 is a transiting three-planet system of sub-Neptunes orbiting a bright (G = 8.9 mag), young (340 ±80 Myr) K-type star. Although a validated planetary system, the orbits of the two outer planets were unconstrained as only two non-consecutive transits were seen in TESS photometry. This left 11 and 7 possible period aliases for each. Aims. To reveal the true orbits of these two long-period planets, precise photometry targeted on the highest-probability period aliases is required. Long-term monitoring of transits in multi-planet systems can also help constrain planetary masses through TTV measurements. Methods. We used the MonoTools package to determine which aliases to follow, and then performed space-based and ground-based photometric follow-up of TOI-2076 c and d with CHEOPS, SAINT-EX, and LCO telescopes. Results. CHEOPS observations revealed a clear detection for TOI-2076 c at P = 21.01538+0.00084 -0.00074 d, and allowed us to rule out three of the most likely period aliases for TOI-2076 d. Ground-based photometry further enabled us to rule out remaining aliases and confirm the P = 35.12537 ±0.00067 d alias. These observations also improved the radius precision of all three sub-Neptunes to 2.518 ±0.036, 3.497 ±0.043, and 3.232 ±0.063 R⊕;. Our observations also revealed a clear anti-correlated TTV signal between planets b and c likely caused by their proximity to the 2:1 resonance, while planets c and d appear close to a 5:3 period commensurability, although model degeneracy meant we were unable to retrieve robust TTV masses. Their inflated radii, likely due to extended H-He atmospheres, combined with low insolation makes all three planets excellent candidates for future comparative transmission spectroscopy with JWST. © 2022 EDP Sciences. All rights reserved. (Less)
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- author
- Osborn, H.P. ; Davies, M.B. LU and Walton, N.
- author collaboration
- organization
- publishing date
- 2022
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- planets and satellites: detection, stars: individual: TOI-2076, techniques: photometric, High resolution transmission electron microscopy, Orbits, Planets, Satellites, Stars, Ground based, High probability, Long term monitoring, Neptune, Outer planets, Planetary system, Planets and satellites: detections, Star: individual: TOI-2076, Stars: individual: proxima Centauri, Techniques: photometric, Photometry
- in
- Astronomy and Astrophysics
- volume
- 664
- article number
- A156
- publisher
- EDP Sciences
- external identifiers
-
- scopus:85141293670
- ISSN
- 0004-6361
- DOI
- 10.1051/0004-6361/202243065
- language
- English
- LU publication?
- yes
- id
- 4f4b2f25-ed5d-42eb-aa53-7ff700d3baf0
- date added to LUP
- 2023-01-11 13:16:29
- date last changed
- 2023-05-10 15:12:30
@article{4f4b2f25-ed5d-42eb-aa53-7ff700d3baf0,
abstract = {{Context. TOI-2076 is a transiting three-planet system of sub-Neptunes orbiting a bright (G = 8.9 mag), young (340 ±80 Myr) K-type star. Although a validated planetary system, the orbits of the two outer planets were unconstrained as only two non-consecutive transits were seen in TESS photometry. This left 11 and 7 possible period aliases for each. Aims. To reveal the true orbits of these two long-period planets, precise photometry targeted on the highest-probability period aliases is required. Long-term monitoring of transits in multi-planet systems can also help constrain planetary masses through TTV measurements. Methods. We used the MonoTools package to determine which aliases to follow, and then performed space-based and ground-based photometric follow-up of TOI-2076 c and d with CHEOPS, SAINT-EX, and LCO telescopes. Results. CHEOPS observations revealed a clear detection for TOI-2076 c at P = 21.01538+0.00084 -0.00074 d, and allowed us to rule out three of the most likely period aliases for TOI-2076 d. Ground-based photometry further enabled us to rule out remaining aliases and confirm the P = 35.12537 ±0.00067 d alias. These observations also improved the radius precision of all three sub-Neptunes to 2.518 ±0.036, 3.497 ±0.043, and 3.232 ±0.063 R⊕;. Our observations also revealed a clear anti-correlated TTV signal between planets b and c likely caused by their proximity to the 2:1 resonance, while planets c and d appear close to a 5:3 period commensurability, although model degeneracy meant we were unable to retrieve robust TTV masses. Their inflated radii, likely due to extended H-He atmospheres, combined with low insolation makes all three planets excellent candidates for future comparative transmission spectroscopy with JWST. © 2022 EDP Sciences. All rights reserved.}},
author = {{Osborn, H.P. and Davies, M.B. and Walton, N.}},
issn = {{0004-6361}},
keywords = {{planets and satellites: detection; stars: individual: TOI-2076; techniques: photometric; High resolution transmission electron microscopy; Orbits; Planets; Satellites; Stars; Ground based; High probability; Long term monitoring; Neptune; Outer planets; Planetary system; Planets and satellites: detections; Star: individual: TOI-2076; Stars: individual: proxima Centauri; Techniques: photometric; Photometry}},
language = {{eng}},
publisher = {{EDP Sciences}},
series = {{Astronomy and Astrophysics}},
title = {{Uncovering the true periods of the young sub-Neptunes orbiting TOI-2076}},
url = {{http://dx.doi.org/10.1051/0004-6361/202243065}},
doi = {{10.1051/0004-6361/202243065}},
volume = {{664}},
year = {{2022}},
}