Key parameters at a glance
- A radius of 9.41 Earth radii
- A mass of 13.10 Earth masses
- Surface gravity around 0.15 g
- An orbital period of 24.140 days
- Semi-major axis 0.1685 AU
- Equilibrium temperature 666 K (393 °C)
- Distance from Earth 352.90 light-years
- Earth Similarity Index 0.154
- Travel time at Voyager 1 speed 6,223,348 years
- Almost certainly tidally locked to its host star given the close orbit
3 siblings around V1298 Tau
V1298 Tau b shares its host star with 3 other confirmed planets. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| V1298 Tau c | Neptune-like | 5.08 | 4.70 | 8.249 | 953 | 2019 |
| V1298 Tau d | Neptune-like | 6.53 | 6.00 | 12.401 | 831 | 2019 |
| V1298 Tau b this | Neptune-like | 9.41 | 13.10 | 24.140 | 666 | 2019 |
| V1298 Tau e | Gas Giant | 10.17 | 15.30 | 48.678 | 527 | 2019 |
V1298 Tau b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#49of 574
top 8.4%
This planet
9.41R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | V1298 Tau b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 9.41 | 11.21 |
| Mass (M⊕) | 1.00 | 13.10 | 317.83 |
| Density (g/cm³) | 5.51 | 0.09 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.15 | 2.53 |
| Insolation (S⊕) | 1.00 | 33.20 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 13.100 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 15756231
Gaia DR2
Gaia DR2 51886335968692480
Gaia DR3
Gaia DR3 51886335968692480
System
V1298 Tau
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 24.14 Earth days (6.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1685 AU.
Transit Fingerprint
Depth
0.500 %
Duration
6.450 h
Impact parameter b
0.260
Rp / R★
0.066100
Transit midpoint (BJD)
2,458,298.2096
Photometric dip
Transit produces a flux drop of 5,000 ppm lasting ≈ 6.45 h.
Extended Orbital Architecture
Planet / star radius ratio
0.066100
Semi-major axis / stellar radius
26.060
Impact parameter (b)
0.260
RV semi-amplitude (K)
41.000 m/s
Transit mid-time (BJD)
2,458,298.2096
Long. of periastron (ω)
91.00°
Sky-projected obliquity (λ)
4.00°
True obliquity (ψ)
8.00°
Angular separation (arcsec)
1.56000
Eq. Temperature
666K
(393 °C)
Insolation (S⊕)
33.20
Earth = 1.00
Earth Similarity (ESI)
0.154
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.
Detection Signatures
Transit photometry
A transit dip has been observed from at least one telescope.
Radial velocity
Stellar wobble has been measured spectroscopically.
Transit timing variations
Gravitational interactions from neighbours have been detected.
Discovery Paper
Primary reference
David et al. 2019Instrument
Kepler CCD Array
Publication
2019-08
Observation locale
Space
Discovery cohort
Planets confirmed in 2019 at K2 (12 shown).
Host System: V1298 Tau
Spectral Class
K-type orange
Effective Temperature
4,970 K — cooler than the Sun (5,778 K)
Estimated Age
0.02 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.320 R☉
Stellar Mass
1.100 M☉
Metallicity [Fe/H]
0.10
Extended Stellar Properties
Surface gravity (log g)
4.227 dex
Stellar density
0.679 g/cm³
Systemic radial velocity
16.15 km/s
Rotational v·sin i
24.77 km/s
Rotation period
2.91 days
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 17 bands
Astrometric Data
Parallax
9.214 mas
Total Proper Motion
16.905 mas/yr
PM Right Ascension
5.23 mas/yr
PM Declination
-16.08 mas/yr
Galactic Cartesian (pc)
x = 0.450 · y = 0.824 · z = 0.345
Equatorial (J2000)
RA 61.33165° · Dec 20.15703°
Galactic ℓ, b
172.895° · -23.377°
Ecliptic λ, β
63.228° · -0.658°
HTM-20 index
-403262256
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