{"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":"2026-09-06T19:23:40.327Z","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":"tres-4-b","name":"TrES-4 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":1682.9016777428528,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":268.3043361,"dec_deg":37.2117397,"epoch_ra_deg":268.535088,"epoch_dec_deg":37.205321,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"TrES-4","semi_major_axis_km":7605555.7463879995,"periapsis_km":null,"mass_kg":1.4805446084677045e+27,"mass_msun":0.000744587,"constellation":"Hercules","discovered":"2007","featured":false,"url":"https://spacecatalog.org/object/tres-4-b","radius_km":115102.31786899999,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"TrES-4","host_v_mag":11.932,"eccentricity":0,"uncertainties":{"mass_kg":[3.606454815498255e+26,3.606454815498255e+26],"radius_km":[12868.582122,12868.582122],"distance_ly":[22.31888092715675,22.91900866215556],"host_mass_solar":[0.38,0.38],"inclination_deg":[0.33,0.33],"host_radius_solar":[0.19,0.19],"host_temperature_k":[75,75],"semi_major_axis_km":[74798.93535,74798.93535],"orbital_period_days":[0.000075,0.000075],"argument_of_periastron_deg":[160,9.5]},"host_mass_solar":1.08,"inclination_deg":82.81,"stars_in_system":2,"discovery_method":"Transit","host_radius_solar":1.66,"planets_in_system":1,"discovery_facility":"TrES","host_spectral_type":"F8 V","host_temperature_k":6200,"orbital_period_days":3.55395,"transit_midpoint_bjd":2460478.712885,"equilibrium_temperature_k":1778,"argument_of_periastron_deg":80.6},"designations":[{"catalog":"Exoplanet","designation":"TrES-4 b"},{"catalog":"Host star","designation":"TrES-4"}],"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."}