{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.673","julian_year":2026.673,"time":"2026-09-03T23:04:39.473Z","years_from_j2000":26.673,"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-3253","name":"NGC 3253","class":"spiral_galaxy_sbc","category":"galaxy","object_type":"Spiral galaxy Sbc","mag":13.59,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":480636357.024662,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":157.11383333333336,"dec_deg":12.704055555555556,"epoch_ra_deg":157.471316,"epoch_dec_deg":12.567029,"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":"Leo","discovered":"1886","featured":false,"url":"https://spacecatalog.org/object/ngc-3253","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.3,"h_mag":11.05,"j_mag":11.75,"k_mag":10.8,"v_mag":13.59,"redshift":0.032382,"hubble_type":"Sbc","wikidata_id":"Q1103830","redshift_cmb":0.03355942282458968,"discovered_by":"Lewis A. Swift","ngc_type_code":"G","uncertainties":{"distance_ly":[24089822.41083514,24089822.41083514]},"major_axis_arcmin":1.15,"minor_axis_arcmin":1.07,"position_angle_deg":150,"surface_brightness":23.3,"radial_velocity_km_s":9551},"designations":[{"catalog":"2MASX","designation":"2MASX J10282730+1242144"},{"catalog":"IRAS","designation":"IRAS 10257+1257"},{"catalog":"LEDA","designation":"LEDA 30829"},{"catalog":"MCG","designation":"MCG +02-27-021"},{"catalog":"NGC","designation":"NGC 3253"},{"catalog":"PGC","designation":"PGC 30829"},{"catalog":"SDSS","designation":"SDSS J102827.32+124214.5"},{"catalog":"UGC","designation":"UGC 5674"}],"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."}