Key parameters at a glance
- A radius of 4.77 Earth radii
- A mass of 20.34 Earth masses
- Surface gravity around 0.89 g
- An orbital period of 7.299 days
- Semi-major axis 0.0680 AU
- Distance from Earth 58.52 light-years
- Earth Similarity Index 0.490
- Travel time at Voyager 1 speed 1,031,935 years
- Almost certainly tidally locked to its host star given the close orbit
2 siblings around HD 153557
HD 153557 b 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 |
|---|---|---|---|---|---|---|
| HD 153557 b this | Neptune-like | 4.77 | 20.34 | 7.299 | — | 2022 |
| HD 153557 c | Neptune-like | 4.36 | 17.48 | 15.270 | — | 2022 |
| HD 153557 d | Gas Giant | 11.90 | 8,725.66 | 40,654.648 | — | 2022 |
HD 153557 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#415of 574
top 72.1%
This planet
4.77R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | HD 153557 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 4.77 | 11.21 |
| Mass (M⊕) | 1.00 | 20.34 | 317.83 |
| Density (g/cm³) | 5.51 | 1.03 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.89 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Minimum mass (M sin i) | 20.341 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
HD
HD 153557
HIP
HIP 83020 A
TIC
TIC 115582979
Gaia DR2
Gaia DR2 1408029509584967168
Gaia DR3
Gaia DR3 1408029509584967168
System
HIP 83020 A
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 7.30 Earth days (2.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0680 AU.
Eq. Temperature
—
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.490
0 = alien, 1 = Earth-identical
Insufficient insolation data. Close-orbiting tidally-locked around a cool host.
Discovery Paper
Primary reference
Feng et al. 2022Instrument
Multiple Instruments
Publication
2022-09
Observation locale
Ground
Discovery cohort
Planets confirmed in 2022 at Multiple Observatories (12 shown).
Host System: HD 153557
Spectral Class
K-type orange
Effective Temperature
4,837 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.745 R☉
Stellar Mass
0.790 M☉
Metallicity [Fe/H]
—
Extended Stellar Properties
Surface gravity (log g)
4.591 dex
Stellar density
2.692 g/cm³
Systemic radial velocity
-7.20 km/s
Rotational v·sin i
2.00 km/s
Multi-band Host Photometry — 7 bands
Astrometric Data
Parallax
55.709 mas
Total Proper Motion
308.766 mas/yr
PM Right Ascension
-145.79 mas/yr
PM Declination
272.18 mas/yr
Galactic Cartesian (pc)
x = -0.181 · y = -0.653 · z = 0.736
Equatorial (J2000)
RA 254.47065° · Dec 47.36786°
Galactic ℓ, b
73.379° · 38.467°
Ecliptic λ, β
239.351° · 69.161°
HTM-20 index
-926956240
Similar Worlds
Kepler-553 b
Neptune-like · K-type orange
Radius 4.74 R⊕ · 2,376.1 ly
Kepler-712 c
Neptune-like · K-type orange
Radius 4.85 R⊕ · 2,845.7 ly
TOI-942 c
Neptune-like · K-type orange
Radius 4.67 R⊕ · 497.7 ly
Kepler-229 c
Neptune-like · K-type orange
Radius 4.92 R⊕ · 2,694.9 ly
Kepler-1321 b
Neptune-like · K-type orange
Radius 4.92 R⊕ · 2,508.6 ly
TOI-544 c
Neptune-like · K-type orange
Radius 4.92 R⊕ · 134.1 ly