V1298 Tau c
V1298 Tau c is a Neptune-like planet orbiting V1298 Tau in the constellation Taurus. It lies about 353 light-years from Earth and was discovered in 2019 using the transit method.
How Big Is V1298 Tau c?
V1298 Tau c has a radius of 5.08 times that of Earth. Its mass is 4.7 times that of Earth, giving it a density of 0.20 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is V1298 Tau c in the Habitable Zone?
V1298 Tau c orbits inside the inner edge of the habitable zone of V1298 Tau. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of V1298 Tau: 0.766–1.854 AU (conservative: 0.970–1.758 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on V1298 Tau c
The equilibrium temperature of V1298 Tau c is about 953 K (680 °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 V1298 Tau c — one full orbit around V1298 Tau — lasts 8.25 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.082 AU — closer to its star than Mercury is to the Sun. Its orbit is nearly circular (eccentricity 0.009).
How Was V1298 Tau c Discovered?
V1298 Tau c was discovered in 2019 using the transit method, with observations from K2.
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 V1298 Tau c?
V1298 Tau c is 352.9 light-years (108.2 parsecs) from Earth. Light arriving here tonight left the planet around the year 1674. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 6,211,040 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. V1298 Tau c scores 0.15, ranking #4,233 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: V1298 Tau
V1298 Tau c belongs to a system of 3 stars; it orbits V1298 Tau.
V1298 Tau
- Surface temperature
- 4,970 K (Sun: 5,772 K)
- Mass
- 1.10 M☉
- Radius
- 1.32 R☉
- Age
- 0.0 billion years (Sun: 4.6)
The V1298 Tau Planetary System
V1298 Tau c is one of 4 known planets in the V1298 Tau system. Its siblings:
- V1298 Tau b (Cold Gas Giant)
- V1298 Tau d (Cold Gas Giant)
- V1298 Tau e (Cold Gas Giant)
V1298 Tau c — Complete Data
| Radius | 5.080 Earth radii (0.453 Jupiter radii) |
|---|---|
| Mass | 4.70 Earth masses (0.015 Jupiter masses) |
| Density | 0.20 g/cm³ (Earth: 5.51) |
| Orbital period | 8.25 days |
| Orbital distance | 0.082 AU |
| Eccentricity | 0.009 |
| Equilibrium temperature | 953 K (680 °C) |
| Earth Similarity Index | 0.15 |
| Distance from Earth | 352.9 light-years (108.2 parsecs) |
| Constellation | Taurus |
| Discovery method | Transit |
| Discovery facility | K2 |
| Discovery year | 2019 |
Data: NASA Exoplanet Archive, last updated 2026-02-26. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About V1298 Tau c
Is V1298 Tau c habitable?
No — V1298 Tau c orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is V1298 Tau c?
V1298 Tau c is about 353 light-years from Earth in the constellation Taurus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 6,211,040 years to get there.
How big is V1298 Tau c compared to Earth?
V1298 Tau c has 5.08 times the radius of Earth and about 4.7 times its mass.
How long is a year on V1298 Tau c?
One orbit around V1298 Tau takes 8.2 Earth days — short enough that 44 of its years would fit into one Earth year.
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