Confirmed Exoplanet Discovered 2023

HIP 29442 c

A super-earth orbiting the g-type yellow (sun-like) TOI-469, located approximately 222.4 light-years from Earth.

Key parameters at a glance

  • A radius of 1.55 Earth radii
  • A mass of 4.50 Earth masses
  • Surface gravity around 1.87 g
  • An orbital period of 3.538 days
  • Semi-major axis 0.0452 AU
  • Equilibrium temperature 1,123 K (850 °C)
  • Distance from Earth 222.41 light-years
  • Earth Similarity Index 0.258
  • Travel time at Voyager 1 speed 3,922,241 years

2 siblings around TOI-469

HIP 29442 c shares its host star with 2 other confirmed planets. Side-by-side measurements below.

Planet Type Radius (R⊕) Mass (M⊕) Period (d) Eq. T (K) Year
HIP 29442 c this Super-Earth 1.55 4.50 3.538 1,123 2023
HIP 29442 d Super-Earth 1.54 5.14 6.430 920 2023
TOI-469.01 Sub-Neptune 3.41 9.10 13.631 716 2021

HIP 29442 c Planet Profile

Physical Specs

Radius
1.55 R⊕
Radius (Jupiter)
0.138 R♃
Mass
4.50 M⊕
Mass (Jupiter)
0.014 M♃
Density
6.30 g/cm³
Surface Gravity
1.87 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.258
HZ Position Inner
Controversial No

Discovery

Year 2023
Method Radial Velocity
Facility Paranal Observatory
Telescope 8.2 m ESO VLT UT3 Melipal Telescope

Size rank in cohort

Rank by radius

#650of 1176

top 55.2%

This planet

1.55R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Metric Earth HIP 29442 c Jupiter
Radius (R⊕)1.001.5511.21
Mass (M⊕)1.004.50317.83
Density (g/cm³)5.516.301.33
Surface Gravity (g)1.001.872.53
Insolation (S⊕)1.00451.000.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 4.500 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

HD

HD 42813

HIP

HIP 29442

TIC

TIC 33692729

Gaia DR2

Gaia DR2 2993561629444856960

Gaia DR3

Gaia DR3 2993561629444856960

System

TOI-469

Percentile among Super-Earth cohort

Radius 1.551 R⊕ · percentile 45 / cohort 1176
Mass 4.500 M⊕ · percentile 86 / cohort 1176
Orbital period 3.54 d · percentile 26 / cohort 1164
Distance 68.19 pc · percentile 14 / cohort 1171
ESI 0.258 · percentile 26 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period
3.538 days
Semi-major axis
0.0452 AU
Eccentricity
Inclination
86.30 °

Year Length

A year here lasts approximately 3.54 Earth days (1.0% of a terrestrial year) at a mean orbital distance of 0.0452 AU.

Transit Fingerprint

Duration

2.429 h

Impact parameter b

0.514

Rp / R★

0.014530

Transit midpoint (BJD)

2,458,471.3600

Extended Orbital Architecture

Planet / star radius ratio

0.014530

Semi-major axis / stellar radius

9.720

Impact parameter (b)

0.514

RV semi-amplitude (K)

2.040 m/s

Transit mid-time (BJD)

2,458,471.3600

Angular separation (arcsec)

0.66300

Eq. Temperature

1,123K

(850 °C)

Insolation (S⊕)

451.00

Earth = 1.00

Earth Similarity (ESI)

0.258

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

Damasso et al. 2023

Instrument

ESPRESSO

Publication

2023-08

Observation locale

Ground

Host System: TOI-469

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,289 K — cooler than the Sun (5,778 K)

Estimated Age

11.20 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.980 R☉

Stellar Mass

0.901 M☉

Metallicity [Fe/H]

0.24

Extended Stellar Properties

Surface gravity (log g)

4.390 dex

Stellar density

1.424 g/cm³

Rotational v·sin i

1.94 km/s

Rotation period

40.00 days

Activity index (log R'HK)

-4.980

Metallicity ratio

[Fe/H]

Distance
68.19 parsec
Light-years 222.41 ly
V-band magnitude
9.49 mag
Voyager-speed travel 3,922,241 yr

Multi-band Host Photometry — 11 bands

7.510.310.32B9.49V9.27Gaia8.76TESS8.06J7.72H7.59K7.56W17.63W27.59W37.47W4

Astrometric Data

Parallax

14.636 mas

Total Proper Motion

180.981 mas/yr

PM Right Ascension

-79.26 mas/yr

PM Declination

162.70 mas/yr

Galactic Cartesian (pc)

x = -0.052 · y = 0.966 · z = -0.253

Equatorial (J2000)

RA 93.05784° · Dec -14.64932°

Galactic ℓ, b

221.872° · -15.183°

Ecliptic λ, β

93.754° · -38.049°

HTM-20 index

-505793275

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