{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.668","julian_year":2026.668,"time":"2026-09-02T00:34:59.103Z","years_from_j2000":26.668,"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-5555","name":"NGC 5555","class":"spiral_galaxy_sb","category":"galaxy","object_type":"Spiral galaxy Sb","mag":15.14,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":542421415.338056,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":214.70033333333336,"dec_deg":-19.138916666666667,"epoch_ra_deg":215.073442,"epoch_dec_deg":-19.262843,"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":"1886","featured":false,"url":"https://spacecatalog.org/object/ngc-5555","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":15.14,"h_mag":11.81,"j_mag":12.43,"k_mag":11.38,"redshift":0.036886,"hubble_type":"Sb","wikidata_id":"Q1121016","redshift_cmb":0.03775846774309821,"discovered_by":"Ormond Stone","ngc_type_code":"G","uncertainties":{"distance_ly":[26156408.619969297,26156408.619969297]},"major_axis_arcmin":0.61,"minor_axis_arcmin":0.37,"wikipedia_article":"NGC 5555","position_angle_deg":113,"surface_brightness":22.57,"radial_velocity_km_s":10854},"designations":[{"catalog":"2MASX","designation":"2MASX J14184808-1908201"},{"catalog":"ESO","designation":"ESO 579-015"},{"catalog":"ESO","designation":"ESO 579-15"},{"catalog":"IRAS","designation":"IRAS 14160-1854"},{"catalog":"IRAS","designation":"IRAS F14160-1854"},{"catalog":"LEDA","designation":"LEDA 51124"},{"catalog":"MCG","designation":"MCG -03-36-011"},{"catalog":"NGC","designation":"NGC 5555"},{"catalog":"PGC","designation":"PGC 51124"}],"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."}