{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.686","julian_year":2026.686,"time":"2026-09-08T12:10:42.533Z","years_from_j2000":26.686,"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-3651-b","name":"HD 3651 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":36.31294646947134,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":9.8387218,"dec_deg":21.2488844,"epoch_ra_deg":10.192283,"epoch_dec_deg":21.396604,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 3651","semi_major_axis_km":44131371.85649999,"periapsis_km":null,"mass_kg":4.3277457785979056e+26,"mass_msun":0.000217649,"constellation":"Pisces","discovered":"2003","featured":false,"url":"https://spacecatalog.org/object/hd-3651-b","radius_km":64418.810000000005,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 3651","host_v_mag":5.88437,"eccentricity":0.645,"uncertainties":{"mass_kg":[2.0879475247621475e+25,2.0879475247621475e+25],"distance_ly":[0.023483259195605524,0.02380941557332227],"eccentricity":[0.02,0.02],"host_radius_solar":[0.0171,0.0171],"semi_major_axis_km":[4338338.2502999995,4338338.2502999995],"orbital_period_days":[0.004,0.004],"argument_of_periastron_deg":[3,3]},"host_mass_solar":0.799,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":0.871954,"planets_in_system":1,"discovery_facility":"Multiple Observatories","host_spectral_type":"K0 V","host_temperature_k":5221,"orbital_period_days":62.25,"periastron_epoch_bjd":2453932.2,"transit_midpoint_bjd":2454414.1,"equilibrium_temperature_k":432.84,"argument_of_periastron_deg":243},"designations":[{"catalog":"Exoplanet","designation":"HD 3651 b"},{"catalog":"Host star","designation":"HD 3651"}],"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."}