{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.681","julian_year":2026.681,"time":"2026-09-06T16:13:36.839Z","years_from_j2000":26.681,"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":"hd-188015-b","name":"HD 188015 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":165.2653935273402,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":298.0191857,"dec_deg":28.0999769,"epoch_ra_deg":298.292312,"epoch_dec_deg":28.168529,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 188015","semi_major_axis_km":179966238.4521,"periapsis_km":null,"mass_kg":2.8470518659335067e+27,"mass_msun":0.00143182,"constellation":"Vulpecula","discovered":"2004","featured":false,"url":"https://spacecatalog.org/object/hd-188015-b","radius_km":86742.16,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 188015","host_v_mag":8.24,"eccentricity":0.137,"uncertainties":{"mass_kg":[2.467699762971398e+26,2.467699762971398e+26],"distance_ly":[0.3551842953335336,0.357141233599834],"eccentricity":[0.026,0.026],"host_radius_solar":[0.026152,0.026152],"semi_major_axis_km":[10471850.949000001,10471850.949000001],"orbital_period_days":[1.7,1.7],"argument_of_periastron_deg":[10,10]},"host_mass_solar":1.09,"stars_in_system":2,"discovery_method":"Radial Velocity","host_radius_solar":1.125296,"planets_in_system":1,"discovery_facility":"W. M. Keck Observatory","host_spectral_type":"G5 IV","host_temperature_k":5746,"orbital_period_days":461.2,"periastron_epoch_bjd":2451787,"transit_midpoint_bjd":2452094.4,"equilibrium_temperature_k":267.98,"argument_of_periastron_deg":222},"designations":[{"catalog":"Exoplanet","designation":"HD 188015 b"},{"catalog":"Host star","designation":"HD 188015"}],"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."}