{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.687","julian_year":2026.687,"time":"2026-09-08T21:55:00.086Z","years_from_j2000":26.687,"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":"pgc-999643","name":"PGC 999643","class":"spiral_galaxy","category":"galaxy","object_type":"Spiral galaxy","mag":15.369,"mag_band":"B","abs_mag":-19.349013170827817,"abs_mag_band":"B","distance_ly":286436599.5787945,"distance_method":"luminosity distance from a spectroscopic redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":27.709208,"dec_deg":-8.75285,"epoch_ra_deg":28.043142,"epoch_dec_deg":-8.619523,"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":"Cetus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/pgc-999643","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":15.369,"h_mag":12.778,"j_mag":13.46,"k_mag":12.526,"redshift":0.01849,"hubble_type":"3","redshift_cmb":0.0201968254918442,"uncertainties":{"distance_ly":[14410930.737364642,14414141.795366429],"stellar_mass_solar":[934141560.9702244,934141560.9702244]},"major_axis_arcmin":0.902097,"minor_axis_arcmin":0.429669,"morphology_source":"SIMBAD (2010ApJS..186..427N, quality D)","position_angle_deg":92,"stellar_mass_solar":2802424682.910673},"designations":[{"catalog":"2MASX","designation":"2MASX 01505020-0845102"},{"catalog":"PGC","designation":"PGC 999643"},{"catalog":"WISExSCOS","designation":"WISExSCOS J015050.17-084510"}],"source":{"id":"glade_plus","name":"GLADE+ (Galaxy List for the Advanced Detector Era)","url":"https://cdsarc.cds.unistra.fr/viz-bin/cat/VII/291","license":"VizieR terms; cite Dalya+ 2022 (2022MNRAS.514.1403D)"},"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."}