Key parameters at a glance
- A radius of 2.08 Earth radii
- A mass of 5.74 Earth masses
- Surface gravity around 1.33 g
- An orbital period of 10.644 days
- Semi-major axis 0.0750 AU
- Equilibrium temperature 494 K (221 °C)
- Distance from Earth 100.06 light-years
- Earth Similarity Index 0.551
- Travel time at Voyager 1 speed 1,764,617 years
- Almost certainly tidally locked to its host star given the close orbit
TOI-1801 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1856of 1978
top 93.8%
This planet
2.08R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | TOI-1801 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.08 | 11.21 |
| Mass (M⊕) | 1.00 | 5.74 | 317.83 |
| Density (g/cm³) | 5.51 | 3.70 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.33 | 2.53 |
| Insolation (S⊕) | 1.00 | 10.73 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 5.738 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
HIP
HIP 57099
TIC
TIC 119584412
Gaia DR2
Gaia DR2 3980045523465047168
Gaia DR3
Gaia DR3 3980045523465047168
System
TOI-1801
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 10.64 Earth days (2.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0750 AU.
Transit Fingerprint
Depth
0.124 %
Duration
2.699 h
Impact parameter b
0.265
Rp / R★
0.034000
Transit midpoint (BJD)
2,458,903.5435
Photometric dip
Transit produces a flux drop of 1,240 ppm lasting ≈ 2.70 h.
Extended Orbital Architecture
Planet / star radius ratio
0.034000
Semi-major axis / stellar radius
30.632
Impact parameter (b)
0.265
RV semi-amplitude (K)
2.459 m/s
Transit mid-time (BJD)
2,458,903.5435
Long. of periastron (ω)
90.00°
Angular separation (arcsec)
2.44000
Eq. Temperature
494K
(221 °C)
Insolation (S⊕)
10.73
Earth = 1.00
Earth Similarity (ESI)
0.551
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
Mallorqu Iacute N et al. 2023Instrument
TESS CCD Array
Publication
2023-10
Observation locale
Space
Discovery cohort
Planets confirmed in 2023 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-1801
Spectral Class
M-type red dwarf
Effective Temperature
3,863 K — cooler than the Sun (5,778 K)
Estimated Age
0.70 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.547 R☉
Stellar Mass
0.556 M☉
Metallicity [Fe/H]
-0.19
Extended Stellar Properties
Surface gravity (log g)
4.780 dex
Stellar density
5.234 g/cm³
Rotational v·sin i
3.00 km/s
Rotation period
15.98 days
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
32.568 mas
Total Proper Motion
209.158 mas/yr
PM Right Ascension
-205.02 mas/yr
PM Declination
41.43 mas/yr
Galactic Cartesian (pc)
x = -0.918 · y = 0.071 · z = 0.391
Equatorial (J2000)
RA 175.57560° · Dec 23.02703°
Galactic ℓ, b
223.815° · 73.833°
Ecliptic λ, β
166.470° · 19.308°
HTM-20 index
1719557436
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