{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.685","julian_year":2026.685,"time":"2026-09-08T06:26:05.987Z","years_from_j2000":26.685,"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":"psr-b1257-12-c","name":"PSR B1257+12 c","class":"super_earth","category":"exoplanet","object_type":"Super-Earth","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":1956.9382663004606,"distance_method":"NASA Exoplanet Archive sy_dist (Konacki and Wolszczan 2003, 2003ApJ...591L.147K)","ra_deg":195.0149029,"dec_deg":12.6823534,"epoch_ra_deg":195.350924,"epoch_dec_deg":12.537377,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"PSR B1257+12","semi_major_axis_km":53855233.45199999,"periapsis_km":null,"mass_kg":2.568032183150293e+25,"mass_msun":0.000012915,"constellation":"Virgo","discovered":"1992","featured":false,"url":"https://spacecatalog.org/object/psr-b1257-12-c","radius_km":12182.171,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"PSR B1257+12","eccentricity":0.0186,"uncertainties":{"mass_kg":[1.1944335735582758e+24,1.1944335735582758e+24],"distance_ly":[326.1563777167434,326.1563777167434],"eccentricity":[0.0002,0.0002],"inclination_deg":[4,4],"orbital_period_days":[0.0001,0.0001],"argument_of_periastron_deg":[0.6,0.6]},"host_mass_solar":1.4,"inclination_deg":53,"stars_in_system":1,"discovery_method":"Pulsar Timing","planets_in_system":3,"discovery_facility":"Arecibo Observatory","orbital_period_days":66.5419,"periastron_epoch_bjd":2449768.6,"argument_of_periastron_deg":250.4},"designations":[{"catalog":"Exoplanet","designation":"PSR B1257+12 c"},{"catalog":"Host star","designation":"PSR B1257+12"}],"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."}