{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.669","julian_year":2026.669,"time":"2026-09-02T04:55:05.940Z","years_from_j2000":26.669,"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-4145","name":"NGC 4145","class":"spiral_galaxy_scd","category":"galaxy","object_type":"Spiral galaxy Scd","mag":11.22,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":58792982.37450613,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":182.50633333333332,"dec_deg":39.88386111111111,"epoch_ra_deg":182.84644,"epoch_dec_deg":39.734447,"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":"Canes Venatici","discovered":"1787","featured":false,"url":"https://spacecatalog.org/object/ngc-4145","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":11.78,"h_mag":8.87,"j_mag":9.47,"k_mag":8.48,"v_mag":11.22,"redshift":0.003379,"hubble_type":"Scd","wikidata_id":"Q1109321","redshift_cmb":0.0041955615932001145,"discovered_by":"William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[14221458.513319137,14221458.513319137]},"major_axis_arcmin":4.62,"minor_axis_arcmin":2.11,"wikipedia_article":"NGC 4145","position_angle_deg":100,"surface_brightness":23.19,"radial_velocity_km_s":1011},"designations":[{"catalog":"2MASX","designation":"2MASX J12100152+3953019"},{"catalog":"LEDA","designation":"LEDA 38693"},{"catalog":"MCG","designation":"MCG +07-25-040"},{"catalog":"NGC","designation":"NGC 4145"},{"catalog":"PGC","designation":"PGC 38693"},{"catalog":"UGC","designation":"UGC 7154"}],"source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-01T22:58:55.274Z","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."}