USco1621 b
USco1621 b is a exoplanet orbiting the M2.5 V star USco1621 A in the constellation Scorpius. It lies about 450 light-years from Earth and was discovered in 2019 using the imaging method.
Is USco1621 b in the Habitable Zone?
USco1621 b orbits beyond the outer edge of the habitable zone of USco1621 A. At that distance, any surface water would almost certainly be frozen.
Habitable zone of USco1621 A: 0.253–0.658 AU (conservative: 0.320–0.623 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 ›
Temperature on USco1621 b
The equilibrium temperature of USco1621 b is about 2,270 K (1,997 °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
USco1621 b orbits at an average distance of 2,880.000 AU.
How Was USco1621 b Discovered?
USco1621 b was discovered in 2019 using the imaging method, with observations from Multiple Observatories.
Direct imaging captures actual pictures of a planet by blocking out the overwhelming glare of its host star. It works best for young, hot, massive planets on wide orbits.
How Far Away Is USco1621 b?
USco1621 b is 449.8 light-years (137.9 parsecs) from Earth. Light arriving here tonight left the planet around the year 1577. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 7,916,480 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. USco1621 b scores 0.07, ranking #4,873 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: USco1621 A
USco1621 A
- Spectral type
- M2.5 V
- Surface temperature
- 3,460 K (Sun: 5,772 K)
- Mass
- 0.36 M☉
- Luminosity
- 0.0955 L☉
- Age
- 0.0 billion years (Sun: 4.6)
Planetary System
USco1621 b is the only planet known to orbit USco1621 A so far.
USco1621 b — Complete Data
| Mass | 5,085.28 Earth masses (16.000 Jupiter masses) |
|---|---|
| Orbital distance | 2,880.000 AU |
| Equilibrium temperature | 2,270 K (1,997 °C) |
| Earth Similarity Index | 0.07 |
| Distance from Earth | 449.8 light-years (137.9 parsecs) |
| Constellation | Scorpius |
| Discovery method | Imaging |
| Discovery facility | Multiple Observatories |
| Discovery year | 2019 |
Data: NASA Exoplanet Archive, last updated 2020-01-13. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About USco1621 b
Is USco1621 b habitable?
No — USco1621 b orbits outside the habitable zone of USco1621 A and is likely too cold for liquid water on its surface.
How far away is USco1621 b?
USco1621 b is about 450 light-years from Earth in the constellation Scorpius. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 7,916,480 years to get there.
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