Confirmed Exoplanet Discovered 2023

TOI-4603 b

A gas giant orbiting the f-type yellow-white TOI-4603, located approximately 735.9 light-years from Earth.

Key parameters at a glance

  • A radius of 11.68 Earth radii
  • A mass of 4,096.81 Earth masses
  • Surface gravity around 30.03 g
  • An orbital period of 7.246 days
  • Semi-major axis 0.0888 AU
  • Equilibrium temperature 1,677 K (1404 °C)
  • Distance from Earth 735.95 light-years
  • Earth Similarity Index 0.080
  • Travel time at Voyager 1 speed 12,978,445 years

TOI-4603 b Planet Profile

Physical Specs

Radius
11.68 R⊕
Radius (Jupiter)
1.042 R♃
Mass
4,096.81 M⊕
Mass (Jupiter)
12.890 M♃
Density
14.10 g/cm³
Surface Gravity
30.03 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.080
HZ Position Inner
Controversial No

Discovery

Year 2023
Method Transit
Facility Transiting Exoplanet Survey Satellite (TESS)
Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#1568of 1771

top 88.5%

This planet

11.68R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Metric Earth TOI-4603 b Jupiter
Radius (R⊕)1.0011.6811.21
Mass (M⊕)1.004,096.81317.83
Density (g/cm³)5.5114.101.33
Surface Gravity (g)1.0030.032.53
Insolation (S⊕)1.001,192.000.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 4,096.808 M⊕ Direct mass measurement (not derived).
Minimum mass (M sin i) 4,036.421 M⊕ Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD

HD 245134

TIC

TIC 437856897

Gaia DR2

Gaia DR2 3402980516507429888

Gaia DR3

Gaia DR3 3402980516507429888

System

TOI-4603

Percentile among Gas Giant cohort

Radius 11.680 R⊕ · percentile 11 / cohort 1771
Mass 4,096.808 M⊕ · percentile 91 / cohort 1747
Orbital period 7.25 d · percentile 42 / cohort 1533
Distance 225.64 pc · percentile 53 / cohort 1759
ESI 0.080 · percentile 18 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
7.246 days
Semi-major axis
0.0888 AU
Eccentricity
0.325
Inclination
80.21 °

Year Length

A year here lasts approximately 7.25 Earth days (2.0% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.0888 AU.

Transit Fingerprint

Depth

0.153 %

Duration

2.854 h

Impact parameter b

0.952

Rp / R★

0.039100

Transit midpoint (BJD)

2,459,549.1260

Photometric dip

Transit produces a flux drop of 1,528 ppm lasting ≈ 2.85 h.

Extended Orbital Architecture

Planet / star radius ratio

0.039100

Semi-major axis / stellar radius

6.970

Impact parameter (b)

0.952

RV semi-amplitude (K)

962.000 m/s

Transit mid-time (BJD)

2,459,549.1260

Long. of periastron (ω)

20.40°

Angular separation (arcsec)

0.39400

Eq. Temperature

1,677K

(1404 °C)

Insolation (S⊕)

1,192.00

Earth = 1.00

Earth Similarity (ESI)

0.080

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.

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

Khandelwal et al. 2023

Instrument

TESS CCD Array

Publication

2023-03

Observation locale

Space

Host System: TOI-4603

Spectral Class

F-type yellow-white

Effective Temperature

6,264 K — hotter than the Sun (5,778 K)

Estimated Age

1.64 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

2.738 R☉

Stellar Mass

1.765 M☉

Metallicity [Fe/H]

0.34

Extended Stellar Properties

Surface gravity (log g)

3.810 dex

Stellar density

0.121 g/cm³

Rotational v·sin i

23.18 km/s

Metallicity ratio

[Fe/H]

Distance
225.64 parsec
Light-years 735.95 ly
V-band magnitude
9.24 mag
Voyager-speed travel 12,978,445 yr

Multi-band Host Photometry — 11 bands

7.79.89.83B9.24V9.07Gaia8.66TESS8.09J7.79H7.79K7.72W17.74W27.76W37.93W4

Astrometric Data

Parallax

4.404 mas

Total Proper Motion

23.036 mas/yr

PM Right Ascension

0.17 mas/yr

PM Declination

-23.04 mas/yr

Galactic Cartesian (pc)

x = 0.100 · y = 0.926 · z = 0.363

Equatorial (J2000)

RA 83.86593° · Dec 21.29424°

Galactic ℓ, b

185.286° · -5.986°

Ecliptic λ, β

84.279° · -2.023°

HTM-20 index

1499203101

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