Tootfinder

Discovery and dynamics of a Sedna-like object with a perihelion of 66 au
Ying-Tung Chen, Patryk Sofia Lykawka, Yukun Huang, JJ Kavelaars, Wesley C. Fraser, Michele T. Bannister, Shiang-Yu Wang, Chan-Kao Chang, Matthew J. Lehner, Fumi Yoshida, Brett Gladman, Mike Alexandersen, Edward Ashton, Young-Jun Choi, A. Paula Granados Contreras, Takashi Ito, Youngmin JeongAhn, Jianghui Ji, Myung-Jin Kim, Samantha M. Lawler, Jian Li, Zhong-Yi Lin, Hong-Kyu Moon, Surhud More, Marco Mu\~noz-Guti\…

Discovery and dynamics of a Sedna-like object with a perihelion of 66 au
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 incl…

A Ground-Based Transit Observation of the Long-Period Extremely Low-Density Planet HIP 41378 f
Juliana Garc\'ia-Mej\'ia, Zo\"e L. de Beurs, Patrick Tamburo, Andrew Vanderburg, David Charbonneau, Karen A. Collins, Khalid Barkaoui, Cristilyn N. Watkins, Chris Stockdale, Richard P. Schwarz, Raquel For\'es-Toribio, Jose A. Mu\~noz, Giovanni Isopi, Franco Mallia, Aldo Zapparata, Adam Popowicz, Andrzej Brudny, Eric Agol, Munazza K. Alam, Zouhair Benkhaldoun, Jehin Emmanuel, …

A Ground-Based Transit Observation of the Long-Period Extremely Low-Density Planet HIP 41378 f
We present a ground-based transit detection of HIP 41378 f, a long-period ($P = 542$ days), extremely low-density ($0.09 \pm 0.02$ g cm$^{-3}$) giant exoplanet in a dynamically complex system. Using photometry from Tierras, TRAPPIST-North, and multiple LCOGT sites, we constrain the transit center time to $T_{C,6} = 2460438.889 \pm 0.049$ BJD TDB. This marks only the second ground-based detection of HIP 41378 f, currently the longest-period and longest-duration transiting exoplanet observed from…

TOI-2407 b: a warm Neptune in the desert
C. Jan\'o Mu\~noz, M. J. Hooton, P. P. Pedersen, K. Barkaoui, B. V. Rackham, A. J. Burgasser, F. J. Pozuelos, K. G. Stassun, D. Queloz, A. H. M. J. Triaud, C. Ziegler, J. M. Almenara, M. Timmermans, X. Bonfils, K. A. Collins, B. O. Demory, G. Dransfield, M. Ghachoui, M. Gillon, E. Jehin, A. W. Mann, D. Sebastian, S. Thompson, J. D. Twicken, J. de Wit S. Z\'u\~niga-Fern\'andez

TOI-2407 b: a warm Neptune in the desert
We present the validation of TOI-2407 b, a warm Neptune-sized planet with a radius of 4.26 $\pm$ 0.26 R$_\oplus$, orbiting an early M-type star with a period of 2.7 days and an equilibrium temperature of 705 $\pm$ 12 K. The planet was identified by TESS photometry and validated in this work through multi-wavelength ground-based follow-up observations. We include an observation with the novel CMOS-based infrared instrument SPIRIT at the SPECULOOS Southern Observatory. The high-precision transit …