Key parameters at a glance
- A radius of 2.41 Earth radii
- A mass of 6.37 Earth masses
- Surface gravity around 1.10 g
- An orbital period of 8.709 days
- Semi-major axis 0.0668 AU
- Equilibrium temperature 451 K (178 °C)
- Distance from Earth 33.95 light-years
- Earth Similarity Index 0.550
- Travel time at Voyager 1 speed 598,712 years
- Almost certainly tidally locked to its host star given the close orbit
1 sibling around GJ 536
GJ 536 b 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 |
|---|---|---|---|---|---|---|
| GJ 536 b this | Sub-Neptune | 2.41 | 6.37 | 8.709 | 451 | 2016 |
| GJ 536 c | Sub-Neptune | 2.30 | 5.89 | 32.761 | 291 | 2025 |
GJ 536 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1312of 1978
top 66.3%
This planet
2.41R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | GJ 536 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.41 | 11.21 |
| Mass (M⊕) | 1.00 | 6.37 | 317.83 |
| Density (g/cm³) | 5.51 | 2.50 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.10 | 2.53 |
| Insolation (S⊕) | 1.00 | 9.90 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Minimum mass (M sin i) | 6.370 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
HD
HD 122303
HIP
HIP 68469
TIC
TIC 119147875
Gaia DR2
Gaia DR2 3657653114880309248
Gaia DR3
Gaia DR3 3657653114880309248
System
GJ 536
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 8.71 Earth days (2.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0668 AU.
Extended Orbital Architecture
RV semi-amplitude (K)
3.030 m/s
Transit mid-time (BJD)
2,460,553.1000
Long. of periastron (ω)
19.20°
Angular separation (arcsec)
6.42000
Eq. Temperature
451K
(178 °C)
Insolation (S⊕)
9.90
Earth = 1.00
Earth Similarity (ESI)
0.550
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
Su Aacute Rez Mascare Ntilde O et al. 2017Instrument
HARPS Spectrograph
Publication
2017-01
Observation locale
Ground
Discovery cohort
Planets confirmed in 2016 at La Silla Observatory (5 shown).
Host System: GJ 536
Spectral Class
M-type red dwarf
Effective Temperature
3,641 K — cooler than the Sun (5,778 K)
Estimated Age
4.20 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.529 R☉
Stellar Mass
0.528 M☉
Metallicity [Fe/H]
-0.08
Extended Stellar Properties
Surface gravity (log g)
4.713 dex
Stellar density
5.445 g/cm³
Systemic radial velocity
-25.62 km/s
Rotational v·sin i
1.20 km/s
Rotation period
43.63 days
Activity index (log R'HK)
-5.120
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 13 bands
Astrometric Data
Parallax
96.040 mas
Total Proper Motion
1,019.344 mas/yr
PM Right Ascension
-825.42 mas/yr
PM Declination
598.11 mas/yr
Galactic Cartesian (pc)
x = -0.863 · y = -0.503 · z = -0.046
Equatorial (J2000)
RA 210.25973° · Dec -2.65229°
Galactic ℓ, b
335.052° · 55.817°
Ecliptic λ, β
209.097° · 9.078°
HTM-20 index
-129712442
Observation Record
Photometric series
1
Stellar spectra
1
Archive notes
1
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