HAT-P-3 b
HAT-P-3 b is a hot Jupiter orbiting HAT-P-3 in the constellation Ursa Major. It lies about 439 light-years from Earth and was discovered in 2007 using the transit method.
How Big Is HAT-P-3 b?
HAT-P-3 b has a radius of 10.54 times that of Earth, or 0.94 times the radius of Jupiter. Its mass is 207 times that of Earth.
Is HAT-P-3 b in the Habitable Zone?
The position of HAT-P-3 b relative to the habitable zone of HAT-P-3 cannot be precisely determined from the available orbital data.
Habitable zone of HAT-P-3: 0.544–1.305 AU (conservative: 0.689–1.238 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 HAT-P-3 b — one full orbit around HAT-P-3 — lasts 2.90 Earth days, shorter than Mercury's 88-day year.
How Was HAT-P-3 b Discovered?
HAT-P-3 b was discovered in 2007 using the transit method, with observations from HATNet.
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 HAT-P-3 b?
HAT-P-3 b is 438.9 light-years (134.6 parsecs) from Earth. Light arriving here tonight left the planet around the year 1588. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 7,724,640 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. HAT-P-3 b scores 0.09, ranking #4,551 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HAT-P-3
HAT-P-3 b belongs to a system of 2 stars; it orbits HAT-P-3.
HAT-P-3
- Surface temperature
- 5,185 K (Sun: 5,772 K)
- Mass
- 1.06 M☉
- Radius
- 0.87 R☉
Planetary System
HAT-P-3 b is the only planet known to orbit HAT-P-3 so far.
HAT-P-3 b — Complete Data
| Radius | 10.536 Earth radii (0.940 Jupiter radii) |
|---|---|
| Mass | 206.59 Earth masses (0.650 Jupiter masses) |
| Orbital period | 2.90 days |
| Earth Similarity Index | 0.09 |
| Distance from Earth | 438.9 light-years (134.6 parsecs) |
| Constellation | Ursa Major |
| Discovery method | Transit |
| Discovery facility | HATNet |
| Discovery year | 2007 |
Data: NASA Exoplanet Archive, last updated 2018-05-22. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HAT-P-3 b
Is HAT-P-3 b habitable?
HAT-P-3 b is not known to orbit within the habitable zone of HAT-P-3, and as a hot Jupiter it is an unlikely candidate for life as we know it.
How far away is HAT-P-3 b?
HAT-P-3 b is about 439 light-years from Earth in the constellation Ursa Major. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 7,724,640 years to get there.
How big is HAT-P-3 b compared to Earth?
HAT-P-3 b has 10.54 times the radius of Earth and about 207 times its mass.
How long is a year on HAT-P-3 b?
One orbit around HAT-P-3 takes 2.9 Earth days — short enough that 126 of its years would fit into one Earth year.
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