HD 49674 b
HD 49674 b is a Neptune-like planet orbiting HD 49674 in the constellation Auriga. It lies about 140 light-years from Earth and was discovered in 2002 using the radial velocity method.
Is HD 49674 b in the Habitable Zone?
HD 49674 b orbits inside the inner edge of the habitable zone of HD 49674. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of HD 49674: 0.727–1.722 AU (conservative: 0.921–1.632 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 49674 b — one full orbit around HD 49674 — lasts 4.95 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.060 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.09).
How Was HD 49674 b Discovered?
HD 49674 b was discovered in 2002 using the radial velocity method, with observations from W. M. Keck Observatory.
The radial velocity method measures the subtle wobble of a star caused by the gravitational pull of an orbiting planet, visible as periodic shifts in the star's light spectrum. The size of the wobble reveals the planet's minimum mass.
How Far Away Is HD 49674 b?
HD 49674 b is 140.4 light-years (43.0 parsecs) from Earth. Light arriving here tonight left the planet around the year 1886. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 2,471,040 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 49674 b scores 0.13, ranking #4,275 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 49674
HD 49674
- Surface temperature
- 5,602 K (Sun: 5,772 K)
- Mass
- 1.03 M☉
- Radius
- 1.02 R☉
Planetary System
HD 49674 b is the only planet known to orbit HD 49674 so far.
HD 49674 b — Complete Data
| Mass (best estimate) | 31.78 Earth masses |
|---|---|
| Orbital period | 4.95 days |
| Orbital distance | 0.060 AU |
| Eccentricity | 0.090 |
| Earth Similarity Index | 0.13 |
| Distance from Earth | 140.4 light-years (43.0 parsecs) |
| Constellation | Auriga |
| Discovery method | Radial Velocity |
| Discovery facility | W. M. Keck Observatory |
| Discovery year | 2002 |
Data: NASA Exoplanet Archive, last updated 2018-09-04. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 49674 b
Is HD 49674 b habitable?
No — HD 49674 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is HD 49674 b?
HD 49674 b is about 140 light-years from Earth in the constellation Auriga. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 2,471,040 years to get there.
How long is a year on HD 49674 b?
One orbit around HD 49674 takes 4.9 Earth days — short enough that 74 of its years would fit into one Earth year.
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