HD 15337 c
HD 15337 c is a mini-Neptune orbiting HD 15337 in the constellation Fornax. It lies about 146 light-years from Earth and was discovered in 2019 using the transit method.
How Big Is HD 15337 c?
HD 15337 c has a radius of 2.53 times that of Earth. Its mass is 6.8 times that of Earth, giving it a density of 2.30 g/cm³ — between that of rocky and gaseous planets.
Is HD 15337 c in the Habitable Zone?
The position of HD 15337 c relative to the habitable zone of HD 15337 cannot be precisely determined from the available orbital data.
Habitable zone of HD 15337: 0.525–1.262 AU (conservative: 0.665–1.197 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
See the full interactive habitable-zone view in the Exoplanet Explorer app ›
Orbit and Year Length
A year on HD 15337 c — one full orbit around HD 15337 — lasts 17.2 Earth days, shorter than Mercury's 88-day year. Its orbit is mildly elliptical (eccentricity 0.10).
How Was HD 15337 c Discovered?
HD 15337 c was discovered in 2019 using the transit method, with observations from Transiting Exoplanet Survey Satellite (TESS).
The transit method watches a star for the tiny, regular dip in brightness that occurs when a planet crosses in front of it. The depth and timing of these dips reveal the planet's size and orbital period.
How Far Away Is HD 15337 c?
HD 15337 c is 146.2 light-years (44.8 parsecs) from Earth. Light arriving here tonight left the planet around the year 1880. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 2,573,120 years to make the journey.
Earth Similarity Index
The Earth Similarity Index (ESI) scores how physically similar a planet is to Earth, from 0 to 1, based on radius, density, escape velocity and surface temperature. HD 15337 c scores 0.28, ranking #2,302 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 15337
HD 15337
- Surface temperature
- 5,131 K (Sun: 5,772 K)
- Mass
- 0.83 M☉
- Radius
- 0.86 R☉
- Age
- 9.6 billion years (Sun: 4.6)
The HD 15337 Planetary System
HD 15337 c is one of 2 known planets in the HD 15337 system. Its siblings:
- HD 15337 b (Super Earth)
HD 15337 c — Complete Data
| Radius | 2.526 Earth radii (0.225 Jupiter radii) |
|---|---|
| Mass | 6.79 Earth masses (0.021 Jupiter masses) |
| Density | 2.30 g/cm³ (Earth: 5.51) |
| Orbital period | 17.18 days |
| Eccentricity | 0.096 |
| Earth Similarity Index | 0.28 |
| Distance from Earth | 146.2 light-years (44.8 parsecs) |
| Constellation | Fornax |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2019 |
Data: NASA Exoplanet Archive, last updated 2025-02-12. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 15337 c
Is HD 15337 c habitable?
HD 15337 c is not known to orbit within the habitable zone of HD 15337, and as a mini-Neptune it is an unlikely candidate for life as we know it.
How far away is HD 15337 c?
HD 15337 c is about 146 light-years from Earth in the constellation Fornax. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 2,573,120 years to get there.
How big is HD 15337 c compared to Earth?
HD 15337 c has 2.53 times the radius of Earth and about 6.8 times its mass.
How long is a year on HD 15337 c?
One orbit around HD 15337 takes 17.2 Earth days — short enough that 21 of its years would fit into one Earth year.
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