NGTS-23 b
NGTS-23 b is a hot Jupiter orbiting the F9 V star NGTS-23 in the constellation Caelum. It lies about 3,506 light-years from Earth and was discovered in 2022 using the transit method.
How Big Is NGTS-23 b?
NGTS-23 b has a radius of 14.20 times that of Earth, or 1.27 times the radius of Jupiter. Its mass is 195 times that of Earth.
Is NGTS-23 b in the Habitable Zone?
NGTS-23 b orbits inside the inner edge of the habitable zone of NGTS-23. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of NGTS-23: 1.022–2.393 AU (conservative: 1.295–2.268 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on NGTS-23 b
The equilibrium temperature of NGTS-23 b is about 1,327 K (1,054 °C) — hot enough to melt many metals. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C.
Orbit and Year Length
A year on NGTS-23 b — one full orbit around NGTS-23 — lasts 4.08 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.050 AU — closer to its star than Mercury is to the Sun.
How Was NGTS-23 b Discovered?
NGTS-23 b was discovered in 2022 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-23 b?
NGTS-23 b is 3,506.0 light-years (1,075.0 parsecs) from Earth. Light arriving here tonight left the planet about 3,506 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 61,705,600 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-23 b scores 0.06, ranking #5,057 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: NGTS-23
NGTS-23
- Spectral type
- F9 V
- Surface temperature
- 6,057 K (Sun: 5,772 K)
- Mass
- 1.01 M☉
- Radius
- 1.24 R☉
- Luminosity
- 1.9200 L☉
- Age
- 6.4 billion years (Sun: 4.6)
Planetary System
NGTS-23 b is the only planet known to orbit NGTS-23 so far.
NGTS-23 b — Complete Data
| Radius | 14.202 Earth radii (1.267 Jupiter radii) |
|---|---|
| Mass | 194.83 Earth masses (0.613 Jupiter masses) |
| Orbital period | 4.08 days |
| Orbital distance | 0.050 AU |
| Equilibrium temperature | 1,327 K (1,054 °C) |
| Earth Similarity Index | 0.06 |
| Distance from Earth | 3,506.0 light-years (1,075.0 parsecs) |
| Constellation | Caelum |
| Discovery method | Transit |
| Discovery facility | Next-Generation Transit Survey (NGTS) |
| Discovery year | 2022 |
Data: NASA Exoplanet Archive, last updated 2022-11-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About NGTS-23 b
Is NGTS-23 b habitable?
No — NGTS-23 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is NGTS-23 b?
NGTS-23 b is about 3,506 light-years from Earth in the constellation Caelum. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 61,705,600 years to get there.
How big is NGTS-23 b compared to Earth?
NGTS-23 b has 14.20 times the radius of Earth and about 195 times its mass.
How long is a year on NGTS-23 b?
One orbit around NGTS-23 takes 4.1 Earth days — short enough that 90 of its years would fit into one Earth year.
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