7 CMa b
7 CMa b is a cold gas giant orbiting 7 CMa in the constellation Canis Major. It lies about 65 light-years from Earth and was discovered in 2011 using the radial velocity method.
Is 7 CMa b in the Habitable Zone?
7 CMa b orbits inside the inner edge of the habitable zone of 7 CMa. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of 7 CMa: 2.683–6.534 AU (conservative: 3.399–6.195 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 7 CMa b — one full orbit around 7 CMa — lasts 735.1 Earth days, longer than an Earth year. It orbits at an average distance of 1.758 AU. Its orbit is mildly elliptical (eccentricity 0.06).
How Was 7 CMa b Discovered?
7 CMa b was discovered in 2011 using the radial velocity method, with observations from Anglo-Australian Telescope.
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 7 CMa b?
7 CMa b is 64.6 light-years (19.8 parsecs) from Earth. Light arriving here tonight left the planet around the year 1962. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 1,136,960 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. 7 CMa b scores 0.27, ranking #2,708 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: 7 CMa
7 CMa
- Surface temperature
- 4,826 K (Sun: 5,772 K)
- Mass
- 1.34 M☉
- Radius
- 4.87 R☉
- Luminosity
- 11.5499 L☉
- Age
- 4.3 billion years (Sun: 4.6)
The 7 CMa Planetary System
7 CMa b is one of 2 known planets in the 7 CMa system. Its siblings:
- 7 CMa c (Cold Gas Giant)
7 CMa b — Complete Data
| Mass (best estimate) | 587.99 Earth masses |
|---|---|
| Orbital period | 735.10 days |
| Orbital distance | 1.758 AU |
| Eccentricity | 0.060 |
| Earth Similarity Index | 0.27 |
| Distance from Earth | 64.6 light-years (19.8 parsecs) |
| Constellation | Canis Major |
| Discovery method | Radial Velocity |
| Discovery facility | Anglo-Australian Telescope |
| Discovery year | 2011 |
Data: NASA Exoplanet Archive, last updated 2019-10-18. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About 7 CMa b
Is 7 CMa b habitable?
No — 7 CMa b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is 7 CMa b?
7 CMa b is about 65 light-years from Earth in the constellation Canis Major. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 1,136,960 years to get there.
How long is a year on 7 CMa b?
One orbit around 7 CMa takes 735.1 Earth days.
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