Key parameters at a glance
- A radius of 1.90 Earth radii
- A mass of 4.27 Earth masses
- Surface gravity around 1.18 g
- An orbital period of 31.393 days
- Semi-major axis 0.1640 AU
- Equilibrium temperature 226 K (-47 °C)
- Distance from Earth 214.00 light-years
- Earth Similarity Index 0.711
- Travel time at Voyager 1 speed 3,773,949 years
- Almost certainly tidally locked to its host star given the close orbit
Context from the literature
K2-288Bb is a super-Earth or mini-Neptune exoplanet orbiting in the habitable zone of K2-288B, a low-mass M-dwarf star in a binary star system in the constellation of Taurus about 226 light-years from Earth. It was discovered by citizen scientists while analysing data from the Kepler space telescope's K2 mission, and was announced on 7 January 2019. K2-288 is the third transiting planet system identified by the Exoplanet Explorers program, after the six planets of K2-138 and the three planets of K2-233.
Excerpted from Wikipedia · full article
K2-288 B b Planet Profile
Physical Specs
Classification
Planet Type
Super-Earth
Discovery
Size rank in cohort
Rank by radius
#125of 1176
top 10.5%
This planet
1.90R⊕
Super-Earth median
1.60R⊕
Nearest-size peers
| Metric | Earth | K2-288 B b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 1.90 | 11.21 |
| Mass (M⊕) | 1.00 | 4.27 | 317.83 |
| Density (g/cm³) | 5.51 | 3.42 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.18 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Star Catalogue Identifiers
TIC
TIC 640381384
Gaia DR2
Gaia DR2 44838019756570112
System
K2-288
Percentile among Super-Earth cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 31.39 Earth days (8.6% of a terrestrial year) at a mean orbital distance of 0.1640 AU.
Transit Fingerprint
Depth
0.153 %
Duration
2.112 h
Impact parameter b
0.370
Rp / R★
0.049000
Transit midpoint (BJD)
2,457,063.4024
Photometric dip
Transit produces a flux drop of 1,531 ppm lasting ≈ 2.11 h.
Extended Orbital Architecture
Planet / star radius ratio
0.049000
Semi-major axis / stellar radius
110.200
Impact parameter (b)
0.370
Transit mid-time (BJD)
2,457,063.4024
Angular separation (arcsec)
2.50000
Eq. Temperature
226K
(-47 °C)
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.711
0 = alien, 1 = Earth-identical
Insufficient insolation data — surface water would be frozen. Close-orbiting tidally-locked around a cool host.
Discovery Paper
Primary reference
Feinstein et al. 2019Instrument
Kepler CCD Array
Publication
2019-01
Observation locale
Space
Discovery cohort
Planets confirmed in 2018 at K2 (12 shown).
Host System: K2-288 B
Spectral Class
M-type red dwarf
Effective Temperature
3,341 K — cooler than the Sun (5,778 K)
Estimated Age
1.00 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.320 R☉
Stellar Mass
0.330 M☉
Metallicity [Fe/H]
-0.21
Extended Stellar Properties
Surface gravity (log g)
4.960 dex
Stellar density
14.200 g/cm³
Systemic radial velocity
71.60 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 6 bands
Astrometric Data
Parallax
15.217 mas
Total Proper Motion
199.719 mas/yr
PM Right Ascension
185.48 mas/yr
PM Declination
-74.07 mas/yr
Galactic Cartesian (pc)
x = 0.539 · y = 0.782 · z = 0.313
Equatorial (J2000)
RA 55.44429° · Dec 18.26849°
Galactic ℓ, b
170.000° · -28.641°
Ecliptic λ, β
57.396° · -1.346°
HTM-20 index
1506479605
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