Key parameters at a glance
- A radius of 12.20 Earth radii
- A mass of 4,776.96 Earth masses
- Surface gravity around 32.09 g
- An orbital period of 16,000.000 days
- Semi-major axis 13.2000 AU
- Distance from Earth 198.45 light-years
- Earth Similarity Index 0.327
- Travel time at Voyager 1 speed 3,499,642 years
1 sibling around HD 68988
HD 68988 c shares its host star with 1 other confirmed planet. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| HD 68988 b | Gas Giant | 13.40 | 626.13 | 6.277 | — | 2001 |
| HD 68988 c this | Gas Giant | 12.20 | 4,776.96 | 16,000.000 | — | 2021 |
HD 68988 c Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#1410of 1771
top 79.6%
This planet
12.20R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | HD 68988 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 12.20 | 11.21 |
| Mass (M⊕) | 1.00 | 4,776.96 | 317.83 |
| Density (g/cm³) | 5.51 | 14.50 | 1.33 |
| Surface Gravity (g) | 1.00 | 32.09 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 4,776.961 M⊕ | Direct mass measurement (not derived). |
| Minimum mass (M sin i) | 4,767.426 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
HD
HD 68988
HIP
HIP 40687
TIC
TIC 73312938
Gaia DR2
Gaia DR2 1090159839002347136
Gaia DR3
Gaia DR3 1090159839002347136
System
HD 68988
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts about 43.81 Earth years on a highly eccentric trajectory at a mean orbital distance of 13.2000 AU.
Extended Orbital Architecture
RV semi-amplitude (K)
121.000 m/s
Transit mid-time (BJD)
2,451,660.0000
Long. of periastron (ω)
-7.45°
Angular separation (arcsec)
217.00000
Eq. Temperature
—
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.327
0 = alien, 1 = Earth-identical
Detection Signatures
Radial velocity
Stellar wobble has been measured spectroscopically.
Astrometry
Positional wobble of the host star was measured.
Discovery Paper
Primary reference
Rosenthal et al. 2021Instrument
Multiple Instruments
Publication
2021-07
Observation locale
Ground
Discovery cohort
Planets confirmed in 2021 at Multiple Observatories (12 shown).
Host System: HD 68988
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,883 K — hotter than the Sun (5,778 K)
Estimated Age
6.00 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
1.256 R☉
Stellar Mass
1.172 M☉
Metallicity [Fe/H]
0.31
Extended Stellar Properties
Surface gravity (log g)
4.309 dex
Stellar density
0.771 g/cm³
Systemic radial velocity
-69.50 km/s
Rotational v·sin i
2.84 km/s
Activity index (log R'HK)
-5.040
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
16.407 mas
Total Proper Motion
131.851 mas/yr
PM Right Ascension
128.33 mas/yr
PM Declination
30.27 mas/yr
Galactic Cartesian (pc)
x = -0.271 · y = 0.393 · z = 0.878
Equatorial (J2000)
RA 124.59354° · Dec 61.46085°
Galactic ℓ, b
155.263° · 33.920°
Ecliptic λ, β
110.897° · 40.508°
HTM-20 index
-286599229
Observation Record
Photometric series
2
RV measurements
3
Stellar spectra
2
Similar Worlds
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Radius 12.20 R⊕ · 303.9 ly
HD 202206 c
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HD 73256 c
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HD 14067 b
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HD 168443 c
Gas Giant · G-type yellow (Sun-like)
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HD 219828 c
Gas Giant · G-type yellow (Sun-like)
Radius 12.20 R⊕ · 238.5 ly