HD152843 b & c: the masses and orbital periods of a sub-Neptune and a super-puff Neptune
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
We present the characterisation of the two transiting planets around HD 152843 (TOI 2319, TIC 349488688) using an intensive
campaign of HARPS-N radial velocities, and two sectors of TESS data. These data reveal a unique and fascinating system:
HD 152843 b and c have near equal masses of around 9 𝑀⊕ but differing radii of 3.05 ± 0.11 𝑅⊕and 5.94+0.18
−0.16 𝑅⊕, respectively,
and orbital periods of 11.62071+9.6𝑒−05
−0.000106 days and 19.502104+7.4𝑒−05
−8.5𝑒−05 days. This indicates that HD 152843 c is in the lowest
fifth-percentile in density of the known exoplanet population, and has the longest orbital period among these low density planets.
Further, HD 152843 c’s radius places it in the ‘Saturn valley’, the observed lack of planets larger than Neptune, but smaller than
Saturn. The orbital periods of these planets indicate they are near a 5 : 3 mean motion resonance, indicating the possibility of
transit timing variations, and hints at the possibility of interaction with a third planet at some point in the evolution of this system.
Further, the brightness of the host star and the low density of HD 152843 c make it a key target for atmospheric characterisation.
campaign of HARPS-N radial velocities, and two sectors of TESS data. These data reveal a unique and fascinating system:
HD 152843 b and c have near equal masses of around 9 𝑀⊕ but differing radii of 3.05 ± 0.11 𝑅⊕and 5.94+0.18
−0.16 𝑅⊕, respectively,
and orbital periods of 11.62071+9.6𝑒−05
−0.000106 days and 19.502104+7.4𝑒−05
−8.5𝑒−05 days. This indicates that HD 152843 c is in the lowest
fifth-percentile in density of the known exoplanet population, and has the longest orbital period among these low density planets.
Further, HD 152843 c’s radius places it in the ‘Saturn valley’, the observed lack of planets larger than Neptune, but smaller than
Saturn. The orbital periods of these planets indicate they are near a 5 : 3 mean motion resonance, indicating the possibility of
transit timing variations, and hints at the possibility of interaction with a third planet at some point in the evolution of this system.
Further, the brightness of the host star and the low density of HD 152843 c make it a key target for atmospheric characterisation.
Date Issued
2024-08
Date Acceptance
2024-06-21
Citation
Monthly Notices of the Royal Astronomical Society, 2024, 532 (4), pp.4632-4644
ISSN
0035-8711
Publisher
Oxford University Press
Start Page
4632
End Page
4644
Journal / Book Title
Monthly Notices of the Royal Astronomical Society
Volume
532
Issue
4
Copyright Statement
© 2024 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
License URL
Identifier
http://dx.doi.org/10.1093/mnras/stae1821
Publication Status
Published
Date Publish Online
2024-07-26