{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.672","julian_year":2026.672,"time":"2026-09-03T08:38:49.403Z","years_from_j2000":26.672,"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":"ngc-307","name":"NGC 307","class":"lenticular_galaxy_s0","category":"galaxy","object_type":"Lenticular galaxy S0","mag":12.79,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":172390537.59711483,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":14.13575,"dec_deg":-1.7719444444444443,"epoch_ra_deg":14.478764,"epoch_dec_deg":-1.626526,"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":"Cetus","discovered":"1831","featured":false,"url":"https://spacecatalog.org/object/ngc-307","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":13.76,"h_mag":9.88,"j_mag":10.61,"k_mag":9.66,"v_mag":12.79,"redshift":0.013336,"hubble_type":"S0","wikidata_id":"Q1036081","redshift_cmb":0.012227767742616802,"discovered_by":"John Frederick William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[15724763.831656106,15724763.831656106]},"major_axis_arcmin":1.61,"minor_axis_arcmin":0.67,"wikipedia_article":"NGC 307","position_angle_deg":79,"surface_brightness":23.49,"radial_velocity_km_s":3971},"designations":[{"catalog":"2MASX","designation":"2MASX J00563259-0146189"},{"catalog":"LEDA","designation":"LEDA 3367"},{"catalog":"MCG","designation":"MCG +00-03-035"},{"catalog":"NGC","designation":"NGC 307"},{"catalog":"PGC","designation":"PGC 3367"},{"catalog":"SDSS","designation":"SDSS J005632.56-014619.0"},{"catalog":"UGC","designation":"UGC 584"}],"source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-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."}