{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.677","julian_year":2026.677,"time":"2026-09-05T02:43:51.443Z","years_from_j2000":26.677,"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-5531","name":"NGC 5531","class":"lenticular_galaxy_s0","category":"galaxy","object_type":"Lenticular galaxy S0","mag":14.7,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":null,"distance_method":null,"ra_deg":214.18041666666667,"dec_deg":10.884777777777778,"epoch_ra_deg":214.508783,"epoch_dec_deg":10.76003,"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":"Boötes","discovered":"1862","featured":false,"url":"https://spacecatalog.org/object/ngc-5531","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.7,"h_mag":10.64,"j_mag":11.34,"k_mag":10.36,"hubble_type":"S0","wikidata_id":"Q1120797","discovered_by":"Heinrich Louis d'Arrest","ngc_type_code":"GPair","major_axis_arcmin":1.07,"minor_axis_arcmin":0.6,"position_angle_deg":170,"surface_brightness":23.29},"designations":[{"catalog":"2MASX","designation":"2MASX J14164323+1053070"},{"catalog":"LEDA","designation":"LEDA 50999"},{"catalog":"MCG","designation":"MCG +02-36-061"},{"catalog":"NGC","designation":"NGC 5531"},{"catalog":"PGC","designation":"PGC 50999"},{"catalog":"SDSS","designation":"SDSS J141643.21+105307.3"},{"catalog":"SDSS","designation":"SDSS J141643.22+105307.4"}],"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."}