Key parameters at a glance
- A radius of 4.24 Earth radii
- A mass of 38.50 Earth masses
- Surface gravity around 2.14 g
- An orbital period of 27.644 days
- Semi-major axis 0.1920 AU
- Equilibrium temperature 748 K (475 °C)
- Distance from Earth 751.16 light-years
- Earth Similarity Index 0.305
- Travel time at Voyager 1 speed 13,246,650 years
TOI-1439 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#511of 574
top 88.9%
This planet
4.24R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | TOI-1439 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 4.24 | 11.21 |
| Mass (M⊕) | 1.00 | 38.50 | 317.83 |
| Density (g/cm³) | 5.51 | 2.76 | 1.33 |
| Surface Gravity (g) | 1.00 | 2.14 | 2.53 |
| Insolation (S⊕) | 1.00 | 68.44 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 38.500 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 232982558
Gaia DR2
Gaia DR2 1643587094012857984
Gaia DR3
Gaia DR3 1643587094013359360
System
TOI-1439
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 27.64 Earth days (7.6% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.1920 AU.
Transit Fingerprint
Depth
0.056 %
Duration
5.628 h
Impact parameter b
0.570
Rp / R★
0.024034
Transit midpoint (BJD)
2,458,703.4747
Photometric dip
Transit produces a flux drop of 560 ppm lasting ≈ 5.63 h.
Extended Orbital Architecture
Planet / star radius ratio
0.024034
Impact parameter (b)
0.570
RV semi-amplitude (K)
7.000 m/s
Transit mid-time (BJD)
2,458,703.4747
Long. of periastron (ω)
110.00°
Angular separation (arcsec)
0.83400
Eq. Temperature
748K
(475 °C)
Insolation (S⊕)
68.44
Earth = 1.00
Earth Similarity (ESI)
0.305
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.
Detection Signatures
Transit photometry
A transit dip has been observed from at least one telescope.
Radial velocity
Stellar wobble has been measured spectroscopically.
Discovery Paper
Primary reference
Polanski et al. 2024Instrument
TESS CCD Array
Publication
2024-06
Observation locale
Space
Discovery cohort
Planets confirmed in 2024 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-1439
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,841 K — hotter than the Sun (5,778 K)
Estimated Age
4.60 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.618 R☉
Stellar Mass
1.231 M☉
Metallicity [Fe/H]
0.23
Extended Stellar Properties
Surface gravity (log g)
4.106 dex
Stellar density
0.405 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
4.314 mas
Total Proper Motion
20.626 mas/yr
PM Right Ascension
-0.59 mas/yr
PM Declination
-20.62 mas/yr
Galactic Cartesian (pc)
x = -0.178 · y = -0.332 · z = 0.926
Equatorial (J2000)
RA 241.76394° · Dec 67.87764°
Galactic ℓ, b
101.189° · 39.995°
Ecliptic λ, β
160.209° · 79.086°
HTM-20 index
-1527444852
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