iot Dra b
iot Dra b is a cold gas giant orbiting the K2 III star iot Dra in the constellation Draco. It lies about 102 light-years from Earth and was discovered in 2002 using the radial velocity method.
Is iot Dra b in the Habitable Zone?
iot Dra b orbits inside the inner edge of the habitable zone of iot Dra. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of iot Dra: 5.809–14.349 AU (conservative: 7.358–13.604 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 iot Dra b — one full orbit around iot Dra — lasts 510.9 Earth days, longer than an Earth year. It orbits at an average distance of 1.453 AU. Its orbit is highly elliptical (eccentricity 0.70), swinging dramatically closer to and farther from its star.
How Was iot Dra b Discovered?
iot Dra b was discovered in 2002 using the radial velocity method, with observations from Lick Observatory.
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 iot Dra b?
iot Dra b is 102.2 light-years (31.3 parsecs) from Earth. Light arriving here tonight left the planet around the year 1924. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 1,798,720 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. iot Dra b scores 0.10, ranking #4,429 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: iot Dra
iot Dra
- Spectral type
- K2 III
- Surface temperature
- 4,504 K (Sun: 5,772 K)
- Mass
- 1.54 M☉
- Radius
- 11.79 R☉
- Luminosity
- 52.7801 L☉
- Age
- 2.7 billion years (Sun: 4.6)
The iot Dra Planetary System
iot Dra b is one of 2 known planets in the iot Dra system. Its siblings:
iot Dra b — Complete Data
| Mass (best estimate) | 3,756.73 Earth masses |
|---|---|
| Orbital period | 510.85 days |
| Orbital distance | 1.453 AU |
| Eccentricity | 0.701 |
| Earth Similarity Index | 0.10 |
| Distance from Earth | 102.2 light-years (31.3 parsecs) |
| Constellation | Draco |
| Discovery method | Radial Velocity |
| Discovery facility | Lick Observatory |
| Discovery year | 2002 |
Data: NASA Exoplanet Archive, last updated 2022-05-03. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About iot Dra b
Is iot Dra b habitable?
No — iot Dra b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is iot Dra b?
iot Dra b is about 102 light-years from Earth in the constellation Draco. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 1,798,720 years to get there.
How long is a year on iot Dra b?
One orbit around iot Dra takes 510.9 Earth days.
Explore iot Dra b in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
