{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.678","julian_year":2026.678,"time":"2026-09-05T13:14:14.666Z","years_from_j2000":26.678,"frame":"date","applied":"Proper motion, then precession and nutation. The catalogued J2000 position is carried along the great circle the object's own published motion puts it on, at a constant velocity, and the result is referred to the true equator and equinox of this instant. Those are separate things: the motion moves the object, and the rotation turns the grid under it by about fifty arcseconds a year, with nutation adding up to another seventeen.","excluded":"Parallax, the radial-velocity perspective term, aberration and refraction; each is below the accuracy of the catalogued positions themselves. An object with no published proper motion comes back where the catalogue has it rather than at a fabricated zero, and says so with a null pm_ra_mas_yr. A body with no fixed position is not propagated at all — its place comes from an ephemeris, which is what /api/v1/visible answers with."},"slug":"gj-15-a-b","name":"GJ 15 A b","class":"super_earth","category":"exoplanet","object_type":"Super-Earth","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":11.618603412128007,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":4.6126677,"dec_deg":44.0247296,"epoch_ra_deg":4.966713,"epoch_dec_deg":44.173934,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"GJ 15 A","semi_major_axis_km":10771046.690399999,"periapsis_km":null,"mass_kg":1.8095668639407878e+25,"mass_msun":0.00000910057,"constellation":"Andromeda","discovered":"2014","featured":false,"url":"https://spacecatalog.org/object/gj-15-a-b","radius_km":9886.055,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"GJ 15 A","host_v_mag":8.09,"eccentricity":0.094,"uncertainties":{"mass_kg":[2.627753861828207e+24,2.7471972191840344e+24],"distance_ly":[0.001793860077442089,0.001793860077442089],"eccentricity":[0.065,0.091],"host_mass_solar":[0.05,0.05],"host_radius_solar":[0.05,0.05],"host_temperature_k":[68,68],"semi_major_axis_km":[598391.4828,448793.61209999997],"orbital_period_days":[0.0016,0.0017],"argument_of_periastron_deg":[74,49]},"host_mass_solar":0.38,"stars_in_system":2,"discovery_method":"Radial Velocity","host_radius_solar":0.38,"planets_in_system":2,"discovery_facility":"W. M. Keck Observatory","host_spectral_type":"M1","host_temperature_k":3607,"orbital_period_days":11.4407,"transit_midpoint_bjd":2455783.63,"equilibrium_temperature_k":550,"argument_of_periastron_deg":55},"designations":[{"catalog":"Exoplanet","designation":"GJ 15 A b"}],"source":{"id":"exoplanet_archive","name":"NASA Exoplanet Archive (Planetary Systems Composite Parameters)","url":"https://exoplanetarchive.ipac.caltech.edu/cgi-bin/TblView/nph-tblView?app=ExoTbls&config=PSCompPars","license":"Public domain (NASA)"},"updated_at":"2026-09-02T19:50:56.720Z","attribution":"Data from SpaceCatalog.org. Individual records carry their source and license in `source`; attribution is required for CC-BY and CC-BY-SA rows."}