Origins of Super Jupiters: TOI-2145b Has a Moderately Eccentric and Nearly Aligned Orbit

TL;DR

This paper characterizes the orbit and possible formation scenarios of the warm super Jupiter TOI-2145b, revealing its eccentricity, near alignment, and suggesting collisions or high initial mass as formation pathways.

Contribution

It provides a detailed observational and simulation-based analysis of TOI-2145b, highlighting potential formation mechanisms for super Jupiters.

Findings

TOI-2145b has a mass of approximately 5.68 Jupiter masses.

The planet's orbit has a moderate eccentricity of about 0.214.

The stellar obliquity is constrained to roughly 6.8 degrees.

Abstract

Super Jupiters are giant planets with several Jupiter masses. It remains an open question whether these planets originate with such high masses or grow through collisions. Previous work demonstrates that warm super Jupiters tend to have more eccentric orbits compared to regular-mass warm Jupiters. This correlation between mass and eccentricity may indicate that planet-planet interactions significantly influence the warm giant planet demographics. Here we conducted a detailed characterization of a warm super Jupiter, TOI-2145b. This analysis utilized previous observations from TESS and Keck/HIRES, enhanced by new Rossiter-McLaughlin effect data from the NEID spectrometer on the 3.5 m WIYN Telescope. TOI-2145b is a $5.68^{+0.37}_{-0.34} M_{\rm Jup}$ planet on a moderate eccentricity ($e = 0.214^{+0.014}_{-0.014}$), 10.26-day orbit, orbiting an evolved A-star. We constrain the projected stellar obliquity to be $\lambda = 6.8^{+2.9}_{-3.8}$$^\circ$ from two NEID observations. Our $N$-body simulations suggest that the formation of super Jupiter TOI-2145b could involve either of two scenarios: a high initial mass or growth via collisions. On a population level, however, the collision scenario can better describe the mass-eccentricity distribution of observed warm Jupiters.