Exoplaneten

Habitable Exoplaneten

Current Number of Potentially Habitable Exoplanets

Subterran (Mars-size)	Terran (Earth-size)	Superterran (Super-Earth)	Total
0	11	21	32

subterran = 0.1 — 0.5 M_E or 0.4 — 0.8 R_E, terran = 0.5 — 5 M_E or 0.8 — 1.5 R_E_, superterran = 5 — 10 M_E or 1.5 — 2.5 R_E. M_E = Earth masses, and R_E = Earth radii.

Conservative Sample of Potentially Habitable Exoplanets

These exoplanets are more likely to have a rocky composition and maintain surface liquid water (i.e. 0.5 < Planet Radius ≤ 1.5 Earth radii or 0.1 < Planet Minimum Mass ≤ 5 Earth masses, and the planet is orbiting within the conservative habitable zone).

Name	Type	Mass (M_E)	Radius (R_E)	Flux (S_E)	T_eq (K)	Period (days)	Distance (ly)	ESI
001. GJ 667C c	M-Warm Terran	≥ 3.8	1.1 - 1.5 - 2.0	0.88	247	28.1	24	0.84
002. Kepler-442 b	K-Warm Terran	8.2 - 2.3 - 1.0	1.3	0.70	233	112.3	1115	0.84
003. GJ 667C f*	M-Warm Terran	≥ 2.7	1.0 - 1.4 - 1.8	0.56	221	39.0	24	0.77
004. Wolf 1061 c (N)	M-Warm Terran	≥ 4.3	1.1 - 1.6 - 2.0	0.60	223	17.9	14	0.76
005. Kapteyn b*	M-Warm Terran	≥ 4.8	1.2 - 1.6 - 2.1	0.43	205	48.6	13	0.67
006. Kepler-62 f	K-Warm Terran	10.2 - 2.8 - 1.2	1.4	0.39	201	267.3	1200	0.67
007. Kepler-186 f	M-Warm Terran	4.7 - 1.5 - 0.6	1.2	0.29	188	129.9	561	0.61
008. GJ 667C e*	M-Warm Terran	≥ 2.7	1.0 - 1.4 - 1.8	0.30	189	62.2	24	0.60

* planet canditate/unconfirmed, (N) = new addition to the catalog

Optimistic Sample of Potentially Habitable Exoplanets

These exoplanets are less likely to have a rocky composition or maintain surface liquid water (i.e. 1.5 < Planet Radius ≤ 2.5 Earth radii or 5 < Planet Minimum Mass ≤ 10 Earth masses, or the planet is orbiting within the optimistic habitable zone).

Name	Type	Mass (M_E)	Radius (R_E)	Flux (S_E)	T_eq (K)	Period (days)	Distance (ly)	ESI
001. Kepler-438 b	M-Warm Terran	4.0 - 1.3 - 0.6	1.1	1.38	276	35.2	473	0.88
002. Kepler-296 e	M-Warm Terran	12.5 - 3.3 - 1.4	1.5	1.22	267	34.1	737	0.85
003. Kepler-62 e	K-Warm Superterran	18.7 - 4.5 - 1.9	1.6	1.10	261	122.4	1200	0.83
004. Kepler-452 b	G-Warm Superterran	19.8 - 4.7 - 1.9	1.6	1.11	261	384.8	1402	0.83
005. GJ 832 c	M-Warm Superterran	≥ 5.4	1.2 - 1.7 - 2.2	1.00	253	35.7	16	0.81
006. K2-3 d	M-Warm Terran	11.1	1.5	1.46	280	44.6	137	0.80
007. Kepler-283 c	K-Warm Superterran	35.3 - 7.0 - 2.8	1.8	0.90	248	92.7	1741	0.79
008. tau Cet e*	G-Warm Terran	≥ 4.3	1.1 - 1.6 - 2.0	1.51	282	168.1	12	0.78
009. GJ 180 c*	M-Warm Superterran	≥ 6.4	1.3 - 1.8 - 2.3	0.79	239	24.3	38	0.77
010. Kepler-440 b	K-Warm Superterran	41.2 - 7.7 - 3.1	1.9	1.43	273	101.1	851	0.75
011. GJ 180 b*	M-Warm Superterran	≥ 8.3	1.3 - 1.9 - 2.4	1.23	268	17.4	38	0.75
012. GJ 163 c	M-Warm Superterran	≥ 7.3	1.3 - 1.8 - 2.4	1.40	277	25.6	49	0.75
013. HD 40307 g*	K-Warm Superterran	≥ 7.1	1.3 - 1.8 - 2.3	0.68	227	197.8	42	0.74
014. K2-18 b	M-Warm Superterran	? - 16.5 - 6.0	2.2	0.94	251	32.9	111	0.73
015. Kepler-61 b	K-Warm Superterran	? - 13.8 - 5.2	2.2	1.27	267	59.9	1063	0.73
016. Kepler-443 b	K-Warm Superterran	? - 19.5 - 7.0	2.3	0.89	247	177.7	2540	0.71
017. Kepler-22 b	G-Warm Superterran	? - 20.4 - 7.2	2.4	1.11	261	289.9	619	0.71
018. GJ 422 b*	M-Warm Superterran	≥ 9.9	1.4 - 2.0 - 2.6	0.68	231	26.2	41	0.71
019. GJ 3293 c*	M-Warm Superterran	≥ 8.6	1.4 - 1.9 - 2.5	0.60	223	48.1	59	0.70
020. Kepler-298 d	K-Warm Superterran	? - 26.8 - 9.1	2.5	1.29	271	77.5	1545	0.68
021. Kepler-174 d	K-Warm Superterran	? - 14.8 - 5.5	2.2	0.43	206	247.4	1174	0.61
022. Kepler-296 f	M-Warm Superterran	28.7 - 6.1 - 2.5	1.8	0.34	194	63.3	737	0.60
023. GJ 682 c*	M-Warm Superterran	≥ 8.7	1.4 - 1.9 - 2.5	0.37	198	57.3	17	0.59
024. KOI-4427 b*	M-Warm Superterran	38.5 - 7.4 - 3.0	1.8	0.24	179	147.7	782	0.52

* planet canditate/unconfirmed, (N) = new addition to the catalog

Tables Legend

Name - Name of the planet. This links to the data of the planet at the Extrasolar Planets Encyclopaedia or NASA Exoplanet Archive.
Type - PHL's classification of planets that includes host star spectral type (F, G, K, M), habitable zone location (hot, warm, cold) and size (miniterran, subterran, terran, superterran, jovian, neptunian) (e.g. Earth = G-Warm Terran, Venus = G-Hot Terran, Mars = G-Warm Subterran).
Mass - Minimum mass of the planet in Earth masses (Earth = 1.0 M_E). Estimated for a pure iron, rocky, and water composition, respectively, when not available.
Radius - Radius of planet in Earth radii (Earth = 1.0 R_E). Estimated for a pure iron, rocky, and water composition, respectively, when not available.
Flux - Average stellar flux of the planet in Earth fluxes (Earth = 1.0 S_E).
T_eq - Equilibrium temperature in kelvins (K) assuming a 0.3 bond albedo (Earth = 255 K). Actual surface temperatures are expected to be larger than the equilibrium temperature depending on the atmosphere of the planets, which are currently unknown (e.g. Earth mean global surface temperature is about 288 K or 15°C).
Period - Orbital period in days (Earth = 365 days).
Distance - Distance from Earth in light years (ly).
ESI - Earth Similarity Index, a measure of similarity to Earth that summarizes how similar are these planets to the stellar flux, mass, and radius of Earth (Earth = 1.0). Results are sorted by this number. Planets more similar to Earth based on only these parameters are not necessarily more habitable

DATA from PHL