Key parameters at a glance
- A radius of 2.60 Earth radii
- A mass of 7.27 Earth masses
- Surface gravity around 1.08 g
- An orbital period of 38.060 days
- Semi-major axis 0.1951 AU
- Equilibrium temperature 553 K (280 °C)
- Distance from Earth 55.13 light-years
- Earth Similarity Index 0.446
- Travel time at Voyager 1 speed 972,295 years
- Almost certainly tidally locked to its host star given the close orbit
2 siblings around HD 48948
HD 48948 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 |
|---|---|---|---|---|---|---|
| HD 48948 b | Sub-Neptune | 2.06 | 4.88 | 7.340 | 957 | 2024 |
| HD 48948 c this | Sub-Neptune | 2.60 | 7.27 | 38.060 | 553 | 2024 |
| HD 48948 d | Sub-Neptune | 3.24 | 10.59 | 151.920 | 349 | 2024 |
HD 48948 c Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1017of 1978
top 51.4%
This planet
2.60R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | HD 48948 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.60 | 11.21 |
| Mass (M⊕) | 1.00 | 7.27 | 317.83 |
| Density (g/cm³) | 5.51 | 2.27 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.08 | 2.53 |
| Insolation (S⊕) | 1.00 | 15.50 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Minimum mass (M sin i) | 7.270 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
HD
HD 48948
HIP
HIP 32769
TIC
TIC 88228576
Gaia DR2
Gaia DR2 1003351437484254464
Gaia DR3
Gaia DR3 1003351437484254464
System
HD 48948
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 38.06 Earth days (10.4% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.1951 AU.
Extended Orbital Architecture
Semi-major axis / stellar radius
61.790
RV semi-amplitude (K)
1.480 m/s
Long. of periastron (ω)
101.00°
Angular separation (arcsec)
11.50000
Eq. Temperature
553K
(280 °C)
Insolation (S⊕)
15.50
Earth = 1.00
Earth Similarity (ESI)
0.446
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
Dalal et al. 2024Instrument
HARPS-N Spectrograph
Publication
2024-07
Observation locale
Ground
Discovery cohort
Planets confirmed in 2024 at Roque de los Muchachos Observatory (2 shown).
Host System: HD 48948
Spectral Class
K-type orange
Effective Temperature
4,593 K — cooler than the Sun (5,778 K)
Estimated Age
11.48 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.679 R☉
Stellar Mass
0.686 M☉
Metallicity [Fe/H]
-0.21
Extended Stellar Properties
Surface gravity (log g)
4.610 dex
Stellar density
3.073 g/cm³
Systemic radial velocity
-53.00 km/s
Rotational v·sin i
2.00 km/s
Rotation period
43.45 days
Activity index (log R'HK)
-4.915
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 7 bands
Astrometric Data
Parallax
59.128 mas
Total Proper Motion
482.492 mas/yr
PM Right Ascension
253.25 mas/yr
PM Declination
410.69 mas/yr
Galactic Cartesian (pc)
x = -0.107 · y = 0.483 · z = 0.869
Equatorial (J2000)
RA 102.48981° · Dec 60.33731°
Galactic ℓ, b
155.499° · 23.165°
Ecliptic λ, β
97.722° · 37.233°
HTM-20 index
1077153194
Similar Worlds
K2-155 c
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 237.4 ly
Kepler-505 b
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 924.4 ly
K2-90 b
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 437.7 ly
Kepler-1362 b
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 2,385.2 ly
Kepler-665 b
Sub-Neptune · K-type orange
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HD 18599 b
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 125.8 ly