{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.682","julian_year":2026.682,"time":"2026-09-07T01:01:01.420Z","years_from_j2000":26.682,"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-3613","name":"NGC 3613","class":"elliptical_galaxy_e","category":"galaxy","object_type":"Elliptical galaxy E","mag":10.81,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":102023248.4430185,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":169.65045833333335,"dec_deg":58,"epoch_ra_deg":170.04038,"epoch_dec_deg":57.853178,"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":"Ursa Major","discovered":"1793","featured":false,"url":"https://spacecatalog.org/object/ngc-3613","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":11.74,"h_mag":8.24,"j_mag":8.93,"k_mag":8,"v_mag":10.81,"redshift":0.006738,"hubble_type":"E","wikidata_id":"Q1105602","redshift_cmb":0.007263653263354097,"discovered_by":"William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[14644052.792807795,14644052.792807795]},"major_axis_arcmin":3.55,"minor_axis_arcmin":1.78,"wikipedia_article":"NGC 3613","position_angle_deg":100,"surface_brightness":23.31,"radial_velocity_km_s":2013},"designations":[{"catalog":"2MASX","designation":"2MASX J11183613+5759597"},{"catalog":"LEDA","designation":"LEDA 34583"},{"catalog":"MCG","designation":"MCG +10-16-109"},{"catalog":"NGC","designation":"NGC 3613"},{"catalog":"PGC","designation":"PGC 34583"},{"catalog":"SDSS","designation":"SDSS J111836.10+580000.0"},{"catalog":"UGC","designation":"UGC 6323"}],"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."}