{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.777","julian_year":2026.777,"time":"2026-10-11T23:27:41.121Z","years_from_j2000":26.777,"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-253","name":"Sculptor Filament","class":"intermediate_spiral_galaxy_sabc","category":"galaxy","object_type":"Intermediate spiral galaxy SABc","mag":11.11,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":null,"distance_method":null,"ra_deg":11.888,"dec_deg":-25.288222222222224,"epoch_ra_deg":12.219411,"epoch_dec_deg":-25.141103,"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":"Sculptor","discovered":"1783","featured":true,"url":"https://spacecatalog.org/object/ngc-253","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":"The brightest galaxy in the Sculptor Group, dusty and bursting with star formation, and one of the easiest galaxies to see from the southern hemisphere.","properties":{"b_mag":7.94,"h_mag":4.09,"j_mag":4.81,"k_mag":3.77,"v_mag":11.11,"redshift":0.000864,"hubble_type":"SABc","wikidata_id":"Q487221","redshift_cmb":-0.00008500063036875893,"discovered_by":"Caroline Herschel","ngc_type_code":"G","major_axis_arcmin":26.79,"minor_axis_arcmin":4.58,"wikipedia_article":"Sculptor Galaxy","position_angle_deg":53,"surface_brightness":22.42,"radial_velocity_km_s":259},"designations":[{"catalog":"2MASX","designation":"2MASX J00473313-2517196"},{"catalog":"Caldwell","designation":"C 65"},{"catalog":"Common name","designation":"Sculptor Filament"},{"catalog":"Common name","designation":"Silver Coin"},{"catalog":"ESO","designation":"ESO 474-029"},{"catalog":"ESO","designation":"ESO 474-29"},{"catalog":"ESO-LV","designation":"ESO-LV 474-0290"},{"catalog":"IRAS","designation":"IRAS 00450-2533"},{"catalog":"IRAS","designation":"IRAS F00450-2533"},{"catalog":"LEDA","designation":"LEDA 2789"},{"catalog":"MCG","designation":"MCG -04-03-009"},{"catalog":"NGC","designation":"NGC 253"},{"catalog":"PGC","designation":"PGC 2789"},{"catalog":"UGCA","designation":"UGCA 13"}],"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."}