Astronomy:TOI-5624 f
 Artistic depiction of the exoplanet TOI-5624 f, the outermost planet in the TOI-5624 system | |
| Discovery | |
|---|---|
| Discovered by | Andrea Bonfant et al. |
| Discovery site | Transiting Exoplanet Survey Satellite |
| Discovery date | April 22, 2026 |
| Transit-timing variation + Radial velocity | |
| Orbital characteristics | |
| 0.2366+0.0040 −0.0041 astronomical unit|AU | |
| Eccentricity | 0 (fixed) |
| Orbital period | 45.37+0.74 −0.90 d |
| 90 (fixed) | |
| Semi-amplitude | 2.59±0.73 m/s |
| Star | TOI-5624 |
| Physical characteristics | |
| Mass | 13.0±3.7 M🜨 |
| Physics | 478.5+7.1 −7.0 K (205.35 °C; 401.63 °F) |
TOI-5624 f is the fifth and outermost exoplanet discovered in the TOI-5624 system, located approximately 331 light-years from Earth in the constellation Ursa Major.[1] The discovery of the object was officially announced by an international team of astronomers led by Andrea Bonfant in late April 2026.[1]
The exoplanet's discovery stemmed from analyzing transit timing variations (TTVs) of the fourth planet in the system, TOI-5624 e.[1] Gravitational perturbations affecting this planet pointed to an unseen outer companion, and the exoplanet was subsequently confirmed using radial velocity measurements from the HARPS-N and SOPHIE spectrographs.[1]
Characteristics
Physical characteristics
The object is classified as a warm Neptune. Since the planet is not transiting, its radius has not been directly measured.[1][2] The minimum mass, determined by the radial velocity method, is 13.0±3.7 M🜨.[1][2] According to numerical modeling of the system's dynamical stability, the planet's true mass cannot exceed 26 M🜨, otherwise the system would become unstable over cosmological timescales. It is hypothesized that the planet possesses a massive hydrogen and helium atmosphere or contains a significant fraction of water ice.[1][2]
The planet receives significantly less energy from its star than the inner planets of the system. Its equilibrium temperature is estimated at 478.5 K, which is about 205 °C, assuming an albedo similar to Neptune's Bond albedo.[1][2]
Orbit
As the planet is the outermost of the four other known planets in the system, its orbital period is the longest, at 45.43 days. Its orbit lies at a distance of 0.2366 AU from its host star, which is approximately 60% of Mercury's distance from the Sun.[1][2] Based on the dynamic stability modeling of the system, the orbital inclination of the exoplanet f will be in the range of 60 to 90 degrees.[1][2] The planet itself is in strong dynamical interaction with the planet TOI-5624 e. Their orbital periods are in a 2:1 ratio, leading to significant transit timing variations (TTVs) for the inner planet.[1][2]
In terms of its physical parameters, TOI-5624 f is most similar to Uranus; however, due to its proximity to the star, it is significantly hotter than the ice giants of the Solar System.
See also
- List of exoplanets discovered in 2026
- Transit-timing variation
- TOI-5624 e
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 "The multi-planet system TOI-5624: Four transiting sub-Neptunes with an outer companion revealed by transit-timing variations". 2026-04-21. arXiv:2604.15035 [astro-ph.EP].
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Cowing, Keith (2026-04-19). "The Multi-planet System TOI-5624: Four Transiting Sub-Neptunes With An Outer Companion Revealed By Transit-timing Variations" (in en-US). https://astrobiology.com/2026/04/the-multi-planet-system-toi-5624-four-transiting-sub-neptunes-with-an-outer-companion-revealed-by-transit-timing-variations.html.
External links
- Martin, Pierre-Yves (2026). "Planet TOI-5624 f" (in en). https://exoplanet.eu/catalog/toi_5624_f--12044/.
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