Key parameters at a glance
- A radius of 2.75 Earth radii
- A mass of 19.50 Earth masses
- Surface gravity around 2.58 g
- An orbital period of 8.112 days
- Semi-major axis 0.0567 AU
- Equilibrium temperature 426 K (153 °C)
- Distance from Earth 239.18 light-years
- Earth Similarity Index 0.517
- Travel time at Voyager 1 speed 4,218,025 years
- Almost certainly tidally locked to its host star given the close orbit
TOI-1448 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#810of 1978
top 40.9%
This planet
2.75R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | TOI-1448 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.75 | 11.21 |
| Mass (M⊕) | 1.00 | 19.50 | 317.83 |
| Density (g/cm³) | 5.51 | — | 1.33 |
| Surface Gravity (g) | 1.00 | 2.58 | 2.53 |
| Insolation (S⊕) | 1.00 | 5.45 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 19.500 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 343628284
Gaia DR2
Gaia DR2 2189711770761074816
Gaia DR3
Gaia DR3 2189711770761074816
System
TOI-1448
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 8.11 Earth days (2.2% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.0567 AU.
Transit Fingerprint
Depth
0.472 %
Duration
3.128 h
Impact parameter b
0.210
Rp / R★
0.066300
Transit midpoint (BJD)
2,458,713.3375
Photometric dip
Transit produces a flux drop of 4,723 ppm lasting ≈ 3.13 h.
Extended Orbital Architecture
Planet / star radius ratio
0.066300
Semi-major axis / stellar radius
32.100
Impact parameter (b)
0.210
RV semi-amplitude (K)
12.500 m/s
Transit mid-time (BJD)
2,458,713.3375
Angular separation (arcsec)
0.77300
Eq. Temperature
426K
(153 °C)
Insolation (S⊕)
5.45
Earth = 1.00
Earth Similarity (ESI)
0.517
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.
Discovery Paper
Primary reference
Hori 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-1448
Spectral Class
M-type red dwarf
Effective Temperature
3,412 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.380 R☉
Stellar Mass
0.372 M☉
Metallicity [Fe/H]
0.37
Extended Stellar Properties
Surface gravity (log g)
4.849 dex
Stellar density
9.510 g/cm³
Systemic radial velocity
-23.70 km/s
Rotation period
42.28 days
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
13.607 mas
Total Proper Motion
66.659 mas/yr
PM Right Ascension
-15.72 mas/yr
PM Declination
-64.78 mas/yr
Galactic Cartesian (pc)
x = 0.386 · y = -0.368 · z = 0.846
Equatorial (J2000)
RA 316.32400° · Dec 57.77109°
Galactic ℓ, b
96.294° · 7.123°
Ecliptic λ, β
359.787° · 67.312°
HTM-20 index
-443110258
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