KELT-19 A b
KELT-19 A b is a hot Jupiter orbiting the A8 V star KELT-19 A in the constellation Canis Minor. It lies about 979 light-years from Earth and was discovered in 2017 using the transit method.
How Big Is KELT-19 A b?
KELT-19 A b has a radius of 21.41 times that of Earth, or 1.91 times the radius of Jupiter. Its mass is 1,294 times that of Earth, giving it a density of 0.74 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is KELT-19 A b in the Habitable Zone?
The position of KELT-19 A b relative to the habitable zone of KELT-19 A cannot be precisely determined from the available orbital data.
Temperature on KELT-19 A b
The equilibrium temperature of KELT-19 A b is about 1,935 K (1,662 °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. It receives 2,340 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on KELT-19 A b — one full orbit around KELT-19 A — lasts 4.61 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.064 AU — closer to its star than Mercury is to the Sun.
How Was KELT-19 A b Discovered?
KELT-19 A b was discovered in 2017 using the transit method, with observations from KELT.
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 KELT-19 A b?
KELT-19 A b is 979.4 light-years (300.3 parsecs) from Earth. Light arriving here tonight left the planet around the year 1047. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 17,237,440 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. KELT-19 A b scores 0.04, ranking #5,312 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: KELT-19 A
KELT-19 A b belongs to a system of 2 stars; it orbits KELT-19 A.
KELT-19 A
- Spectral type
- A8 V
- Surface temperature
- 7,500 K (Sun: 5,772 K)
- Mass
- 1.62 M☉
- Radius
- 1.83 R☉
- Luminosity
- 9.4999 L☉
Planetary System
KELT-19 A b is the only planet known to orbit KELT-19 A so far.
KELT-19 A b — Complete Data
| Radius | 21.409 Earth radii (1.910 Jupiter radii) |
|---|---|
| Mass | 1,293.57 Earth masses (4.070 Jupiter masses) |
| Density | 0.74 g/cm³ (Earth: 5.51) |
| Orbital period | 4.61 days |
| Orbital distance | 0.064 AU |
| Equilibrium temperature | 1,935 K (1,662 °C) |
| Stellar irradiation | 2,340.00× Earth |
| Earth Similarity Index | 0.04 |
| Distance from Earth | 979.4 light-years (300.3 parsecs) |
| Constellation | Canis Minor |
| Discovery method | Transit |
| Discovery facility | KELT |
| Discovery year | 2017 |
Data: NASA Exoplanet Archive, last updated 2018-01-08. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About KELT-19 A b
Is KELT-19 A b habitable?
KELT-19 A b is not known to orbit within the habitable zone of KELT-19 A, and as a hot Jupiter it is an unlikely candidate for life as we know it.
How far away is KELT-19 A b?
KELT-19 A b is about 979 light-years from Earth in the constellation Canis Minor. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 17,237,440 years to get there.
How big is KELT-19 A b compared to Earth?
KELT-19 A b has 21.41 times the radius of Earth and about 1,294 times its mass.
How long is a year on KELT-19 A b?
One orbit around KELT-19 A takes 4.6 Earth days — short enough that 79 of its years would fit into one Earth year.
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