HD 63433 d
| Artist's impression of HD 63433 d as compared with Earth | |
| Discovery | |
|---|---|
| Discovered by | Capistrant, Soares-Furtado et al. (THYME) | 
| Discovery date | 10 January 2024 | 
| Transit | |
| Designations | |
| TOI-1726 d, BD+27 1490 d, HIP 38228 d, V377 Geminorum d | |
| Orbital characteristics | |
| 0.0503+0.0025 −0.0027 AU | |
| Eccentricity | 0.16+0.36 −0.12 | 
| 4.20975+0.000012 −0.000023 d | |
| Inclination | 88.73°+0.85° −1.06° | 
| Star | HD 63433 | 
| Physical characteristics | |
| 1.073+0.046 −0.044 R🜨 | |
| Temperature | 1040±40 K (767 ± 40°C) (mean),, 1,530 K (1,260 °C) (daytime) | 
HD 63433 d (TOI-1726 d) is a confirmed exoplanet orbiting HD 63433, a Sun-like star located 73 light-years away in the constellation Gemini. Its radius is measured at around 1.1 R🜨, which makes it similar to the Earth in size. It was the third (and most recent) exoplanet to be discovered in orbit around this star; the other two, HD 63433 b and c, were discovered in 2020. Orbiting its star at a distance of 0.0503 astronomical units (7,520,000 km), HD 63433 d is the innermost planet orbiting HD 63433, and completes an orbit around it just every 4 days. Due to the proximity of its star, the planet is scorching hot, having a temperature estimated at 1260 °C at daytime. The proximity of its star also causes it to be tidally locked.