HD 20781 e
| Discovery | |
|---|---|
| Discovered by | Mayor et al. |
| Discovery date | 2011, published in 2019 |
| Radial velocity | |
| Orbital characteristics | |
| 0.3374+0.0155 −0.0170 AU | |
| Eccentricity | 0.06+0.06 −0.04 |
| 85.5073+0.0983 −0.0947 d | |
| 2,455,513.3912+14.3623 −16.0090 JD | |
| 70.59°+61.40° −67.58° | |
| Semi-amplitude | 2.60±0.14 m/s |
| Star | HD 20781 |
| Physical characteristics | |
| ~2.17 R🜨 (estimate) | |
| Mass | ≥14.03±1.56 M🜨 |
HD 20781 e is a hot Neptune around the star HD 20781. The planet has a minimum mass of 14.03 Earth masses and it orbits with a semi-major axis of 0.3374 astronomical units and an orbital eccentricity of approximately 0.06. With the same composition as Neptune, it would have a radius of 3.79 times that of the Earth. With the same composition as Earth, it would have a radius of 2.08 times that of the Earth. It orbits near the inner edge of the habitable zone of HD 20781.
This planet was initially reported in a 2011 preprint, which referred to it as HD 20781 c. However, the 2017 paper (published in a journal in 2019) that confirmed the planet designated it HD 20781 e, using the c designation for a different, shorter-period planet.