Key parameters at a glance
- A radius of 2.47 Earth radii
- A mass of 6.60 Earth masses
- Surface gravity around 1.08 g
- An orbital period of 6.400 days
- Semi-major axis 0.0607 AU
- Equilibrium temperature 715 K (442 °C)
- Distance from Earth 334.48 light-years
- Earth Similarity Index 0.362
- Travel time at Voyager 1 speed 5,898,488 years
- Almost certainly tidally locked to its host star given the close orbit
TOI-1244 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1242of 1978
top 62.7%
This planet
2.47R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | TOI-1244 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.47 | 11.21 |
| Mass (M⊕) | 1.00 | 6.60 | 317.83 |
| Density (g/cm³) | 5.51 | 2.66 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.08 | 2.53 |
| Insolation (S⊕) | 1.00 | 56.63 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 6.600 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 219850915
Gaia DR2
Gaia DR2 1649087121757063040
Gaia DR3
Gaia DR3 1649087121757063040
System
TOI-1244
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 6.40 Earth days (1.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0607 AU.
Transit Fingerprint
Depth
0.103 %
Duration
2.210 h
Impact parameter b
0.455
Rp / R★
0.031100
Transit midpoint (BJD)
2,459,913.8083
Photometric dip
Transit produces a flux drop of 1,027 ppm lasting ≈ 2.21 h.
Extended Orbital Architecture
Planet / star radius ratio
0.031100
Impact parameter (b)
0.455
RV semi-amplitude (K)
2.700 m/s
Transit mid-time (BJD)
2,459,913.8083
Long. of periastron (ω)
90.00°
Angular separation (arcsec)
0.59200
Eq. Temperature
715K
(442 °C)
Insolation (S⊕)
56.63
Earth = 1.00
Earth Similarity (ESI)
0.362
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.
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-1244
Spectral Class
K-type orange
Effective Temperature
4,599 K — cooler than the Sun (5,778 K)
Estimated Age
5.90 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.721 R☉
Stellar Mass
0.730 M☉
Metallicity [Fe/H]
0.03
Extended Stellar Properties
Surface gravity (log g)
4.595 dex
Stellar density
2.780 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
9.722 mas
Total Proper Motion
87.203 mas/yr
PM Right Ascension
-56.41 mas/yr
PM Declination
-66.50 mas/yr
Galactic Cartesian (pc)
x = -0.083 · y = -0.340 · z = 0.937
Equatorial (J2000)
RA 256.27956° · Dec 69.51909°
Galactic ℓ, b
100.615° · 34.506°
Ecliptic λ, β
143.782° · 84.096°
HTM-20 index
1419776999
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