Key parameters at a glance
- A radius of 11.46 Earth radii
- A mass of 140.16 Earth masses
- Surface gravity around 1.07 g
- An orbital period of 3.478 days
- Semi-major axis 0.0407 AU
- Equilibrium temperature 963 K (690 °C)
- Distance from Earth 385.21 light-years
- Earth Similarity Index 0.141
- Travel time at Voyager 1 speed 6,793,175 years
- Almost certainly tidally locked to its host star given the close orbit
TOI-1259 A b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#1595of 1771
top 90.0%
This planet
11.46R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | TOI-1259 A b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 11.46 | 11.21 |
| Mass (M⊕) | 1.00 | 140.16 | 317.83 |
| Density (g/cm³) | 5.51 | 0.51 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.07 | 2.53 |
| Insolation (S⊕) | 1.00 | 153.14 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 140.162 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 288735205
Gaia DR2
Gaia DR2 2294170838587572736
Gaia DR3
Gaia DR3 2294170838587572736
System
TOI-1259
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 3.48 Earth days (1.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0407 AU.
Transit Fingerprint
Depth
2.676 %
Duration
2.475 h
Impact parameter b
0.065
Rp / R★
0.147620
Transit midpoint (BJD)
2,458,686.7005
Photometric dip
Transit produces a flux drop of 26,759 ppm lasting ≈ 2.48 h.
Extended Orbital Architecture
Planet / star radius ratio
0.147620
Semi-major axis / stellar radius
12.314
Impact parameter (b)
0.065
RV semi-amplitude (K)
72.000 m/s
Transit mid-time (BJD)
2,458,686.7005
Angular separation (arcsec)
0.34500
Eq. Temperature
963K
(690 °C)
Insolation (S⊕)
153.14
Earth = 1.00
Earth Similarity (ESI)
0.141
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
Martin et al. 2021Instrument
TESS CCD Array
Publication
2021-11
Observation locale
Space
Discovery cohort
Planets confirmed in 2021 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-1259 A
Spectral Class
K-type orange
Effective Temperature
4,775 K — cooler than the Sun (5,778 K)
Estimated Age
4.80 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.711 R☉
Stellar Mass
0.744 M☉
Metallicity [Fe/H]
-0.50
Extended Stellar Properties
Surface gravity (log g)
4.605 dex
Stellar density
2.920 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
8.438 mas
Total Proper Motion
100.363 mas/yr
PM Right Ascension
-5.66 mas/yr
PM Declination
100.20 mas/yr
Galactic Cartesian (pc)
x = 0.039 · y = -0.182 · z = 0.982
Equatorial (J2000)
RA 282.10017° · Dec 79.25648°
Galactic ℓ, b
110.883° · 26.756°
Ecliptic λ, β
80.082° · 76.882°
HTM-20 index
840492823
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