{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.687","julian_year":2026.687,"time":"2026-09-08T21:01:28.515Z","years_from_j2000":26.687,"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":"3c-48","name":"3C 48","class":"quasar","category":"black_hole","object_type":"Quasar","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":6441709596.12415,"distance_method":"luminosity distance from a published redshift, flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":24.42208,"dec_deg":33.15974,"epoch_ra_deg":24.805823,"epoch_dec_deg":33.296714,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Triangulum","discovered":"1960","featured":false,"url":"https://spacecatalog.org/object/3c-48","radius_km":null,"radius_kind":null,"data_quality":null,"description":"The first radio source matched to a starlike point of light, in 1960. Its spectrum made no sense to anybody for three years, until 3C 273 showed that such lines were ordinary hydrogen shifted far to the red, and this became the second quasar understood.","properties":{"redshift":0.3702,"accretion":"quasar"},"designations":[{"catalog":"Common name","designation":"3C 48"}],"source":{"id":"curated","name":"SpaceCatalog curated data","url":"https://spacecatalog.org/releases","license":"CC-BY-4.0"},"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."}