{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.778","julian_year":2026.778,"time":"2026-10-12T03:02:34.310Z","years_from_j2000":26.778,"frame":"date","applied":"Proper motion, then precession and nutation. The catalogued position is carried along the great circle the object's own published motion puts it on, at a constant velocity, from the epoch that position was measured at, 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. The motion runs from position_epoch_jyear where the upstream publishes one — a timed pulsar's position belongs to the year it was timed — and from J2000 where it does not. 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-147","name":"NGC 147","class":"elliptical_galaxy_e","category":"galaxy","object_type":"Elliptical galaxy E","mag":9.72,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":null,"distance_method":null,"ra_deg":8.3005,"dec_deg":48.50875,"epoch_ra_deg":8.668151,"epoch_dec_deg":48.657396,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"position_epoch_jyear":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Cassiopeia","discovered":"1829","featured":false,"url":"https://spacecatalog.org/object/ngc-147","source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-4.0","attribution":"OpenNGC, Mattia Verga (github.com/mattiaverga/OpenNGC). Fields derived from it stay under CC BY-SA 4.0.","commercial_use":"allowed"},"radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":10.6,"h_mag":7.34,"j_mag":7.9,"k_mag":7.2,"v_mag":9.72,"redshift":-0.000644,"hubble_type":"E","wikidata_id":"Q493581","redshift_cmb":-0.0015157428908286752,"discovered_by":"John Frederick William Herschel","ngc_type_code":"G","major_axis_arcmin":9.4,"minor_axis_arcmin":5.41,"wikipedia_article":"NGC 147","position_angle_deg":26,"surface_brightness":24.29,"radial_velocity_km_s":-193},"designations":[{"catalog":"2MASX","designation":"2MASX J00331212+4830314"},{"catalog":"Caldwell","designation":"C 17"},{"catalog":"LEDA","designation":"LEDA 2004"},{"catalog":"MCG","designation":"MCG +08-02-005"},{"catalog":"NGC","designation":"NGC 147"},{"catalog":"PGC","designation":"PGC 2004"},{"catalog":"UGC","designation":"UGC 326"}],"updated_at":"2026-10-01T09:42:28.932Z","attribution":"Data from SpaceCatalog.org. Each record names its upstream in `source`, with that producer's terms in `source.license`, the acknowledgement it asks for in `source.attribution`, and whether its terms allow commercial use in `source.commercial_use`; those terms govern the record, and citing SpaceCatalog does not discharge them."}