_version_ 1866910309364531200
author Lowson, Nataliea
Zhou, George
Huang, Chelsea X.
Wright, Duncan J.
Edwards, Billy
Nabbie, Emma
Venner, Alex
Quinn, Samuel N.
Collins, Karen A.
Gillen, Edward
Battley, Matthew
Triaud, Amaury
Hellier, Coel
Seager, Sara
Winn, Joshua N.
Jenkins, Jon M.
Wohler, Bill
Shporer, Avi
Schwarz, Richard P.
Murgas, Felipe
Pallé, Enric
Anderson, David R.
West, Richard G.
Wittenmyer, Robert A.
Bowler, Brendan P.
Horner, Jonathan
Kane, Stephen R.
Kielkopf, John
Plavchan, Peter
Zhang, Hui
Fairnington, Tyler
Okumura, Jack
Mengel, Matthew W.
Addison, Brett C.
author_facet Lowson, Nataliea
Zhou, George
Huang, Chelsea X.
Wright, Duncan J.
Edwards, Billy
Nabbie, Emma
Venner, Alex
Quinn, Samuel N.
Collins, Karen A.
Gillen, Edward
Battley, Matthew
Triaud, Amaury
Hellier, Coel
Seager, Sara
Winn, Joshua N.
Jenkins, Jon M.
Wohler, Bill
Shporer, Avi
Schwarz, Richard P.
Murgas, Felipe
Pallé, Enric
Anderson, David R.
West, Richard G.
Wittenmyer, Robert A.
Bowler, Brendan P.
Horner, Jonathan
Kane, Stephen R.
Kielkopf, John
Plavchan, Peter
Zhang, Hui
Fairnington, Tyler
Okumura, Jack
Mengel, Matthew W.
Addison, Brett C.
contents We report the discovery of two mini-Neptunes in near 2:1 resonance orbits ($P=7.610303$ d for HIP 113103 b and $P=14.245651$ d for HIP 113103 c) around the adolescent K-star HIP 113103 (TIC 121490076). The planet system was first identified from the TESS mission, and was confirmed via additional photometric and spectroscopic observations, including a $\sim$17.5 hour observation for the transits of both planets using ESA CHEOPS. We place $\leq4.5$ min and $\leq2.5$ min limits on the absence of transit timing variations over the three year photometric baseline, allowing further constraints on the orbital eccentricities of the system beyond that available from the photometric transit duration alone. With a planetary radius of $R_{p}=1.829^{+0.096}_{-0.067}\,R_{\oplus}$, HIP 113103 b resides within the radius gap, and this might provide invaluable information on the formation disparities between super-Earths and mini-Neptunes. Given the larger radius $R_{p}=2.40^{+0.10}_{-0.08}\,R_{\oplus}$ for HIP 113103 c, and close proximity of both planets to HIP 113103, it is likely that HIP 113103 b might have lost (or is still losing) its primordial atmosphere. We therefore present simulated atmospheric transmission spectra of both planets using JWST, HST, and Twinkle. It demonstrates a potential metallicity difference (due to differences in their evolution) would be a challenge to detect if the atmospheres are in chemical equilibrium. As one of the brightest multi sub-Neptune planet systems suitable for atmosphere follow up, HIP 113103 b and HIP 113103 c could provide insight on planetary evolution for the sub-Neptune K-star population.
format Preprint
id arxiv_https___arxiv_org_abs_2309_04137
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Two mini-Neptunes Transiting the Adolescent K-star HIP 113103 Confirmed with TESS and CHEOPS
Lowson, Nataliea
Zhou, George
Huang, Chelsea X.
Wright, Duncan J.
Edwards, Billy
Nabbie, Emma
Venner, Alex
Quinn, Samuel N.
Collins, Karen A.
Gillen, Edward
Battley, Matthew
Triaud, Amaury
Hellier, Coel
Seager, Sara
Winn, Joshua N.
Jenkins, Jon M.
Wohler, Bill
Shporer, Avi
Schwarz, Richard P.
Murgas, Felipe
Pallé, Enric
Anderson, David R.
West, Richard G.
Wittenmyer, Robert A.
Bowler, Brendan P.
Horner, Jonathan
Kane, Stephen R.
Kielkopf, John
Plavchan, Peter
Zhang, Hui
Fairnington, Tyler
Okumura, Jack
Mengel, Matthew W.
Addison, Brett C.
Earth and Planetary Astrophysics
We report the discovery of two mini-Neptunes in near 2:1 resonance orbits ($P=7.610303$ d for HIP 113103 b and $P=14.245651$ d for HIP 113103 c) around the adolescent K-star HIP 113103 (TIC 121490076). The planet system was first identified from the TESS mission, and was confirmed via additional photometric and spectroscopic observations, including a $\sim$17.5 hour observation for the transits of both planets using ESA CHEOPS. We place $\leq4.5$ min and $\leq2.5$ min limits on the absence of transit timing variations over the three year photometric baseline, allowing further constraints on the orbital eccentricities of the system beyond that available from the photometric transit duration alone. With a planetary radius of $R_{p}=1.829^{+0.096}_{-0.067}\,R_{\oplus}$, HIP 113103 b resides within the radius gap, and this might provide invaluable information on the formation disparities between super-Earths and mini-Neptunes. Given the larger radius $R_{p}=2.40^{+0.10}_{-0.08}\,R_{\oplus}$ for HIP 113103 c, and close proximity of both planets to HIP 113103, it is likely that HIP 113103 b might have lost (or is still losing) its primordial atmosphere. We therefore present simulated atmospheric transmission spectra of both planets using JWST, HST, and Twinkle. It demonstrates a potential metallicity difference (due to differences in their evolution) would be a challenge to detect if the atmospheres are in chemical equilibrium. As one of the brightest multi sub-Neptune planet systems suitable for atmosphere follow up, HIP 113103 b and HIP 113103 c could provide insight on planetary evolution for the sub-Neptune K-star population.
title Two mini-Neptunes Transiting the Adolescent K-star HIP 113103 Confirmed with TESS and CHEOPS
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2309.04137