{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.671","julian_year":2026.671,"time":"2026-09-02T22:21:15.649Z","years_from_j2000":26.671,"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-4355","name":"NGC 4355","class":"intermediate_spiral_galaxy_saba","category":"galaxy","object_type":"Intermediate spiral galaxy SABa","mag":13.37,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":115958929.27571882,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":186.72758333333334,"dec_deg":-0.8776111111111111,"epoch_ra_deg":187.07187,"epoch_dec_deg":-1.026285,"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":"1786","featured":false,"url":"https://spacecatalog.org/object/ngc-4355","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":13.83,"h_mag":10.35,"j_mag":11.04,"k_mag":10.12,"v_mag":13.37,"redshift":0.00708,"hubble_type":"SABa","wikidata_id":"Q1960466","redshift_cmb":0.008249677584633908,"discovered_by":"William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[14821355.230484618,14821355.230484618]},"major_axis_arcmin":1.41,"minor_axis_arcmin":0.68,"position_angle_deg":64,"surface_brightness":22.98,"radial_velocity_km_s":2115},"designations":[{"catalog":"2MASX","designation":"2MASX J12265462-0052395"},{"catalog":"IRAS","designation":"IRAS 12243-0036"},{"catalog":"IRAS","designation":"IRAS F12243-0036"},{"catalog":"LEDA","designation":"LEDA 40762"},{"catalog":"MCG","designation":"MCG +00-32-012"},{"catalog":"NGC","designation":"NGC 4355"},{"catalog":"NGC","designation":"NGC 4418"},{"catalog":"PGC","designation":"PGC 40762"},{"catalog":"SDSS","designation":"SDSS J122654.61-005239.4"},{"catalog":"SDSS","designation":"SDSS J122654.62-005239.2"},{"catalog":"SDSS","designation":"SDSS J122654.62-005239.3"},{"catalog":"SDSS","designation":"SDSS J122654.62-005239.4"},{"catalog":"UGC","designation":"UGC 7545"}],"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."}