_version_ 1866917447098957824
author Hu, Tong
Lin, Zitao
Wang, Sharon X.
Wang, Mu-Tian
Mireles, Ismael
Bean, Jacob
Brady, Madison
Brown, Nina
Feng, Qikang
Gan, Tianjun
Ji, Chengyang
Li, Xue
Zhang, Jiayue
Basant, Ritvik
Chazov, Nikita
Charbonneau, David
Collins, Karen A.
Das, Tanya
Dragomir, Diana
Essack, Zahra
Garcia-Mejia, Juliana
Huang, Yang
Liu, Jinzhong
Mann, Christopher R.
Osborn, Hugh P.
Scholz, Aleks
Seifahrt, Andreas
Tamburo, Patrick
Wang, Shuming
Yaqup, Shahidin
author_facet Hu, Tong
Lin, Zitao
Wang, Sharon X.
Wang, Mu-Tian
Mireles, Ismael
Bean, Jacob
Brady, Madison
Brown, Nina
Feng, Qikang
Gan, Tianjun
Ji, Chengyang
Li, Xue
Zhang, Jiayue
Basant, Ritvik
Chazov, Nikita
Charbonneau, David
Collins, Karen A.
Das, Tanya
Dragomir, Diana
Essack, Zahra
Garcia-Mejia, Juliana
Huang, Yang
Liu, Jinzhong
Mann, Christopher R.
Osborn, Hugh P.
Scholz, Aleks
Seifahrt, Andreas
Tamburo, Patrick
Wang, Shuming
Yaqup, Shahidin
contents TOI-4600b and c, originally identified by the Transiting Exoplanet Survey Satellite (TESS) and reported by I. Mireles et al. (2023), are a rare pair of transiting long-period giant planets ($\rm P_b=82.7$ days, $\rm P_c=482.8$ days) orbiting an early K dwarf. In this work, we refine the orbital parameters of the TOI-4600 system by combining new TESS photometry, ground-based transit follow-up, and radial velocity (RV) observations from MAROON-X. We obtain improved constraints on planetary masses and eccentricities, and update other parameters, such as the stellar age. For TOI-4600b, we measure a mass of $M_p = 74.7^{+4.7}_{-4.4}\,M_{\oplus}$ and an eccentricity of $e=0.153^{+0.020}_{-0.018}$, and $M_p = 212.53^{+13.26}_{-13.03}\,M_{\oplus}$ and $e=0.219^{+0.015}_{-0.018}$ for TOI-4600c. We find significant transit timing variations (TTV) in both planets, with semi-amplitudes of approximately $1$\,hr. We derive Transit Spectroscopy Metric values of 16.87 for TOI-4600b and 10.09 for TOI-4600c, indicating that both planets are promising JWST targets for studying the atmospheres of temperate and cold Jupiters, a relatively poorly characterized sample thus far. These updated parameters and TTV ephemerides are important for planning and interpreting future photometric, spectroscopic, and dynamical studies of the TOI-4600 system.
format Preprint
id arxiv_https___arxiv_org_abs_2604_26426
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle RV and TTV Measurements of Two Transiting Long-Period Giants around TOI-4600
Hu, Tong
Lin, Zitao
Wang, Sharon X.
Wang, Mu-Tian
Mireles, Ismael
Bean, Jacob
Brady, Madison
Brown, Nina
Feng, Qikang
Gan, Tianjun
Ji, Chengyang
Li, Xue
Zhang, Jiayue
Basant, Ritvik
Chazov, Nikita
Charbonneau, David
Collins, Karen A.
Das, Tanya
Dragomir, Diana
Essack, Zahra
Garcia-Mejia, Juliana
Huang, Yang
Liu, Jinzhong
Mann, Christopher R.
Osborn, Hugh P.
Scholz, Aleks
Seifahrt, Andreas
Tamburo, Patrick
Wang, Shuming
Yaqup, Shahidin
Earth and Planetary Astrophysics
TOI-4600b and c, originally identified by the Transiting Exoplanet Survey Satellite (TESS) and reported by I. Mireles et al. (2023), are a rare pair of transiting long-period giant planets ($\rm P_b=82.7$ days, $\rm P_c=482.8$ days) orbiting an early K dwarf. In this work, we refine the orbital parameters of the TOI-4600 system by combining new TESS photometry, ground-based transit follow-up, and radial velocity (RV) observations from MAROON-X. We obtain improved constraints on planetary masses and eccentricities, and update other parameters, such as the stellar age. For TOI-4600b, we measure a mass of $M_p = 74.7^{+4.7}_{-4.4}\,M_{\oplus}$ and an eccentricity of $e=0.153^{+0.020}_{-0.018}$, and $M_p = 212.53^{+13.26}_{-13.03}\,M_{\oplus}$ and $e=0.219^{+0.015}_{-0.018}$ for TOI-4600c. We find significant transit timing variations (TTV) in both planets, with semi-amplitudes of approximately $1$\,hr. We derive Transit Spectroscopy Metric values of 16.87 for TOI-4600b and 10.09 for TOI-4600c, indicating that both planets are promising JWST targets for studying the atmospheres of temperate and cold Jupiters, a relatively poorly characterized sample thus far. These updated parameters and TTV ephemerides are important for planning and interpreting future photometric, spectroscopic, and dynamical studies of the TOI-4600 system.
title RV and TTV Measurements of Two Transiting Long-Period Giants around TOI-4600
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2604.26426