_version_ 1866915425375223808
author Chen, Ying-Tung
Lykawka, Patryk Sofia
Huang, Yukun
Kavelaars, JJ
Fraser, Wesley C.
Bannister, Michele T.
Wang, Shiang-Yu
Chang, Chan-Kao
Lehner, Matthew J.
Yoshida, Fumi
Gladman, Brett
Alexandersen, Mike
Ashton, Edward
Choi, Young-Jun
Contreras, A. Paula Granados
Ito, Takashi
JeongAhn, Youngmin
Ji, Jianghui
Kim, Myung-Jin
Lawler, Samantha M.
Li, Jian
Lin, Zhong-Yi
Moon, Hong-Kyu
More, Surhud
Muñoz-Gutiérrez, Marco
Ohtsuki, Keiji
Peltier, Lowell
Pike, Rosemary E.
Terai, Tsuyoshi
Urakawa, Seitaro
Zhang, Hui
Zhao, Haibin
Zhou, Ji-Lin
author_facet Chen, Ying-Tung
Lykawka, Patryk Sofia
Huang, Yukun
Kavelaars, JJ
Fraser, Wesley C.
Bannister, Michele T.
Wang, Shiang-Yu
Chang, Chan-Kao
Lehner, Matthew J.
Yoshida, Fumi
Gladman, Brett
Alexandersen, Mike
Ashton, Edward
Choi, Young-Jun
Contreras, A. Paula Granados
Ito, Takashi
JeongAhn, Youngmin
Ji, Jianghui
Kim, Myung-Jin
Lawler, Samantha M.
Li, Jian
Lin, Zhong-Yi
Moon, Hong-Kyu
More, Surhud
Muñoz-Gutiérrez, Marco
Ohtsuki, Keiji
Peltier, Lowell
Pike, Rosemary E.
Terai, Tsuyoshi
Urakawa, Seitaro
Zhang, Hui
Zhao, Haibin
Zhou, Ji-Lin
contents Trans-Neptunian objects (TNOs) with large perihelion distances ($q > 60$ au) and semi-major axes ($a > 200$ au) provide insights into the early evolution of the solar system and the existence of a hypothetical distant planet. These objects are still rare and their detection is challenging, yet they play a crucial role in constraining models of solar system formation. Here we report the discovery of a Sedna-like TNO, 2023\,KQ$_{14}$, nicknamed `Ammonite', with $q = 66$ au, $a = 252$ au, and inclination $i=11^\circ$. Ammonite's orbit does not align with those of the other Sedna-like objects and fills the previously unexplained `$q$-gap' in the observed distribution of distant solar system objects. Simulations demonstrate that Ammonite is dynamically stable over 4.5 billion years. % with less than 1\% variation in its semi-major axis. Our analysis suggests that Ammonite and the other Sedna-like objects may have shared a primordial orbital clustering around 4.2 billion years ago. Furthermore, Ammonite's stable orbit favors larger orbits ($\sim$ 500 au) rather than closer ones for a large hypothetical planet in present-day trans-Neptunian space.
format Preprint
id arxiv_https___arxiv_org_abs_2508_02162
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Discovery and dynamics of a Sedna-like object with a perihelion of 66 au
Chen, Ying-Tung
Lykawka, Patryk Sofia
Huang, Yukun
Kavelaars, JJ
Fraser, Wesley C.
Bannister, Michele T.
Wang, Shiang-Yu
Chang, Chan-Kao
Lehner, Matthew J.
Yoshida, Fumi
Gladman, Brett
Alexandersen, Mike
Ashton, Edward
Choi, Young-Jun
Contreras, A. Paula Granados
Ito, Takashi
JeongAhn, Youngmin
Ji, Jianghui
Kim, Myung-Jin
Lawler, Samantha M.
Li, Jian
Lin, Zhong-Yi
Moon, Hong-Kyu
More, Surhud
Muñoz-Gutiérrez, Marco
Ohtsuki, Keiji
Peltier, Lowell
Pike, Rosemary E.
Terai, Tsuyoshi
Urakawa, Seitaro
Zhang, Hui
Zhao, Haibin
Zhou, Ji-Lin
Earth and Planetary Astrophysics
Trans-Neptunian objects (TNOs) with large perihelion distances ($q > 60$ au) and semi-major axes ($a > 200$ au) provide insights into the early evolution of the solar system and the existence of a hypothetical distant planet. These objects are still rare and their detection is challenging, yet they play a crucial role in constraining models of solar system formation. Here we report the discovery of a Sedna-like TNO, 2023\,KQ$_{14}$, nicknamed `Ammonite', with $q = 66$ au, $a = 252$ au, and inclination $i=11^\circ$. Ammonite's orbit does not align with those of the other Sedna-like objects and fills the previously unexplained `$q$-gap' in the observed distribution of distant solar system objects. Simulations demonstrate that Ammonite is dynamically stable over 4.5 billion years. % with less than 1\% variation in its semi-major axis. Our analysis suggests that Ammonite and the other Sedna-like objects may have shared a primordial orbital clustering around 4.2 billion years ago. Furthermore, Ammonite's stable orbit favors larger orbits ($\sim$ 500 au) rather than closer ones for a large hypothetical planet in present-day trans-Neptunian space.
title Discovery and dynamics of a Sedna-like object with a perihelion of 66 au
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2508.02162