NGTS-3 A b
NGTS-3 A b is a hot Jupiter orbiting the G6 V star NGTS-3 A in the constellation Columba. It lies about 2,427 light-years from Earth and was discovered in 2018 using the transit method.
How Big Is NGTS-3 A b?
NGTS-3 A b has a radius of 16.59 times that of Earth, or 1.48 times the radius of Jupiter. Its mass is 756 times that of Earth, giving it a density of 0.31 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is NGTS-3 A b in the Habitable Zone?
NGTS-3 A b orbits inside the inner edge of the habitable zone of NGTS-3 A. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of NGTS-3 A: 0.663–1.569 AU (conservative: 0.839–1.487 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 NGTS-3 A b — one full orbit around NGTS-3 A — lasts just 40.2 hours, shorter than Mercury's 88-day year. It orbits at an average distance of 0.023 AU — closer to its star than Mercury is to the Sun.
How Was NGTS-3 A b Discovered?
NGTS-3 A b was discovered in 2018 using the transit method, with observations from Next-Generation Transit Survey (NGTS).
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 NGTS-3 A b?
NGTS-3 A b is 2,426.5 light-years (744.0 parsecs) from Earth. Light arriving here tonight left the planet about 2,427 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 42,706,400 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. NGTS-3 A b scores 0.06, ranking #5,222 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: NGTS-3 A
NGTS-3 A b belongs to a system of 2 stars; it orbits NGTS-3 A.
NGTS-3 A
- Spectral type
- G6 V
- Surface temperature
- 5,600 K (Sun: 5,772 K)
- Mass
- 1.02 M☉
- Radius
- 0.93 R☉
Planetary System
NGTS-3 A b is the only planet known to orbit NGTS-3 A so far.
NGTS-3 A b — Complete Data
| Radius | 16.589 Earth radii (1.480 Jupiter radii) |
|---|---|
| Mass | 756.44 Earth masses (2.380 Jupiter masses) |
| Density | 0.31 g/cm³ (Earth: 5.51) |
| Orbital period | 1.68 days |
| Orbital distance | 0.023 AU |
| Earth Similarity Index | 0.06 |
| Distance from Earth | 2,426.5 light-years (744.0 parsecs) |
| Constellation | Columba |
| Discovery method | Transit |
| Discovery facility | Next-Generation Transit Survey (NGTS) |
| Discovery year | 2018 |
Data: NASA Exoplanet Archive, last updated 2018-06-06. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About NGTS-3 A b
Is NGTS-3 A b habitable?
No — NGTS-3 A b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is NGTS-3 A b?
NGTS-3 A b is about 2,427 light-years from Earth in the constellation Columba. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 42,706,400 years to get there.
How big is NGTS-3 A b compared to Earth?
NGTS-3 A b has 16.59 times the radius of Earth and about 756 times its mass.
How long is a year on NGTS-3 A b?
One orbit around NGTS-3 A takes 1.7 Earth days — short enough that 218 of its years would fit into one Earth year.
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