TRAPPIST-1 e (Temperate Terrestrial World)
Coordinates, Gaia distance (12.47 pc), 6.10-day orbital period, mass 0.692 M⊕, radius 0.920 R⊕, and JWST transit spectroscopy for TRAPPIST-1 e.
Aliases: 2MASS J23062928-0502285 e
Exoplanets Catalog & Characterization Data
Planets orbiting stars beyond our Solar System, ranging from temperate M-dwarf terrestrial worlds and sub-Neptunes to short-period hot Jupiters and warm Saturns.
Cataloged Profiles6 Objects
ClassificationExoplanets
Machine-Readable DataJSON Shard (exoplanets.json)
Physical & Observational Overview
Since the 1995 radial-velocity discovery of 51 Pegasi b and the 1999 transit detection of HD 209458 b, over 5,700 confirmed exoplanets have been cataloged in the NASA Exoplanet Archive. These systems reveal planetary architectures absent from our Solar System, including resonant seven-planet chains (TRAPPIST-1) and volatile-rich sub-Neptunes (K2-18 b).
Every FastAstro exoplanet profile distinguishes direct geometric observables (such as transit radius or RV minimum mass M sin i) from model-dependent quantities (equilibrium temperature and atmospheric composition).
Classification Criteria: Characterized by detection method (transit photometry, radial velocity, transit timing variations), planetary mass (M_⊕ or M_Jup), radius (R_⊕ or R_Jup), orbital period, semi-major axis, and equilibrium temperature T_eq.
Visual Observing Regime: While exoplanets themselves are unresolved next to their host stars, amateur observers can view several host stars directly (51 Pegasi in binoculars; HD 209458 and Proxima Centauri in small telescopes) and detect ~1.5% hot-Jupiter transit dips with backyard CMOS photometry.
Companion Theoretical Reference: Explore exoplanet interiors, atmospheres, and habitability physics on FastCosmos.us.
Exoplanets Comparison Table
| Object | Constellation | Classification | RA (J2000) | Dec (J2000) | Min. Instrument | Best Season |
|---|---|---|---|---|---|---|
| TRAPPIST-1 e (Temperate Terrestrial World) | Aquarius | Temperate terrestrial exoplanet in a 7-planet resonant chain | 23h 06m 29.28s | -05° 02′ 28.6″ | 250–350 mm telescope + near-IR/CMOS camera (V = 18.80, J = 11.35) | Late Summer to Autumn (August–November) |
| Proxima Centauri b (Nearest Exoplanet) | Centaurus | Nearest known exoplanet (radial-velocity habitable-zone terrestrial candidate) | 14h 29m 42.95s | -62° 40′ 46.1″ | 80–100 mm telescope to view the 11.13-mag host star Proxima Centauri | Late Spring to Summer (April–July) |
| 51 Pegasi b (Dimidium First Hot Jupiter) | Pegasus | Prototype Hot Jupiter exoplanet orbiting a Sun-like G2 IV-V star | 22h 57m 27.98s | +20° 46′ 07.8″ | Naked eye under dark skies; 7×50 binoculars to view host star 51 Pegasi (V = 5.49) | Autumn (September–December) |
| HD 209458 b (Osiris First Transiting Planet) | Pegasus | First transiting exoplanet & first exoplanet with a detected atmosphere | 22h 03m 10.77s | +18° 53′ 03.5″ | 10×50 binoculars to see host star (V = 7.65); 100 mm+ scope + CCD for 1.5% transit | Late Summer to Autumn (August–November) |
| K2-18 b (Temperate Sub-Neptune in Leo) | Leo | Temperate sub-Neptune exoplanet with methane- and CO2-rich H2 atmosphere | 11h 30m 14.52s | +07° 35′ 18.2″ | 200–250 mm telescope to visually spot the 13.50-mag host star K2-18 | Spring (March–June) |
| WASP-39 b (JWST Benchmark Saturn Exoplanet) | Virgo | Low-density inflated Saturn-mass exoplanet (JWST ERS benchmark) | 14h 29m 18.42s | -03° 26′ 40.2″ | 130–150 mm telescope to visually spot the 12.11-mag host star WASP-39 | Spring to Early Summer (April–July) |
Detailed Exoplanets Profiles
Proxima Centauri b (Nearest Exoplanet)
Coordinates, ESPRESSO minimum mass (1.07 M⊕), 11.186-day habitable-zone orbit at 0.04856 AU, and stellar flare environment of Proxima Centauri b.
Aliases: Alpha Centauri C b, GJ 551 b
51 Pegasi b (Dimidium First Hot Jupiter)
Coordinates, Gaia DR3 distance (15.46 pc), 4.2308-day orbital period, Nobel-winning radial-velocity discovery, and observing guide for 51 Pegasi b.
Aliases: Dimidium, HD 217014 b, Helvetios b
HD 209458 b (Osiris First Transiting Planet)
Coordinates, Gaia DR3 distance (48.3 pc), 3.5247-day transit period, 1.359 R♃ inflated radius, and atmospheric escape data for HD 209458 b.
Aliases: Osiris, V376 Pegasi b, HIP 108859 b
K2-18 b (Temperate Sub-Neptune in Leo)
Coordinates, Gaia DR3 distance (38.07 pc), 32.94-day habitable-zone orbit, 8.63 M⊕ mass, 2.61 R⊕ radius, and JWST CH4/CO2 spectrum of K2-18 b.
Aliases: EPIC 201912552 b, BD+08 2518 b
WASP-39 b (JWST Benchmark Saturn Exoplanet)
Coordinates, Gaia DR3 distance (213 pc), 4.055-day period, 0.28 M♃ mass, 1.27 R♃ radius, and JWST CO2/SO2 photochemical spectrum of WASP-39 b.
Aliases: Bocaprins, GSC 04980-00761 b
Related Astrometric & Optical Reference Guides
Exoplanet Transit & Radial Velocity Methods
How astronomers detect and characterize exoplanets using photometric transit depth ((Rp/R*)²), Doppler radial velocity (M sin i), and JWST transmission spectra.
Trigonometric Parallax, Parsecs & Gaia DR3
How trigonometric parallax (d_pc = 1 / p_arcsec), the distance modulus equation, Hipparcos, and Gaia DR3 microarcsecond astrometry measure cosmic distances.