{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.679","julian_year":2026.679,"time":"2026-09-06T01:31:24.271Z","years_from_j2000":26.679,"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-5521","name":"NGC 5521","class":"spiral_galaxy_sbc","category":"galaxy","object_type":"Spiral galaxy Sbc","mag":14.62,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":285535724.1787561,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":213.84883333333332,"dec_deg":4.4085277777777785,"epoch_ra_deg":214.186802,"epoch_dec_deg":4.283292,"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":"Virgo","discovered":"1828","featured":false,"url":"https://spacecatalog.org/object/ngc-5521","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.62,"h_mag":12.3,"j_mag":12.86,"k_mag":11.96,"redshift":0.01928,"hubble_type":"Sbc","wikidata_id":"Q1120701","redshift_cmb":0.020134237751769257,"discovered_by":"John Frederick William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[18267884.805192355,18267884.805192355]},"major_axis_arcmin":0.61,"minor_axis_arcmin":0.49,"position_angle_deg":40,"surface_brightness":22.24,"radial_velocity_km_s":5724},"designations":[{"catalog":"2MASX","designation":"2MASX J14152371+0424304"},{"catalog":"IRAS","designation":"IRAS F14129+0438"},{"catalog":"LEDA","designation":"LEDA 50931"},{"catalog":"MCG","designation":"MCG +01-36-030"},{"catalog":"NGC","designation":"NGC 5521"},{"catalog":"PGC","designation":"PGC 50931"},{"catalog":"SDSS","designation":"SDSS J141523.71+042430.6"},{"catalog":"SDSS","designation":"SDSS J141523.71+042430.7"},{"catalog":"SDSS","designation":"SDSS J141523.72+042430.6"},{"catalog":"SDSS","designation":"SDSS J141523.72+042430.7"},{"catalog":"SDSS","designation":"SDSS J141526.33+042429.9"},{"catalog":"UGC","designation":"UGC 9122"}],"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."}