{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.654","julian_year":2026.654,"time":"2026-08-27T23:06:10.890Z","years_from_j2000":26.654,"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-54004","name":"PGC 54004","class":"elliptical_galaxy_den","category":"galaxy","object_type":"Elliptical galaxy dEn","mag":15.39,"mag_band":"B","abs_mag":-16.730264395245534,"abs_mag_band":"B","distance_ly":86592196.1310181,"distance_method":"luminosity distance from a spectroscopic redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":226.904953,"dec_deg":2.01939,"epoch_ra_deg":227.245194,"epoch_dec_deg":1.915917,"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":null,"featured":false,"url":"https://spacecatalog.org/object/pgc-54004","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":15.39,"h_mag":14.001,"j_mag":14.713,"k_mag":13.904,"redshift":0.00641,"hubble_type":"dEn","redshift_cmb":0.0061701210531705,"uncertainties":{"distance_ly":[5462564.558434171,5462915.784486528],"stellar_mass_solar":[37368959.70527095,37368959.70527095]},"major_axis_arcmin":0.709453,"minor_axis_arcmin":0.615096,"morphology_source":"SIMBAD (2015ApJS..217...27A, quality C)","position_angle_deg":137,"stellar_mass_solar":270924957.8632144},"designations":[{"catalog":"2MASX","designation":"2MASX 15073718+0201098"},{"catalog":"PGC","designation":"PGC 54004"},{"catalog":"WISExSCOS","designation":"WISExSCOS J150737.23+020109.6"}],"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":"2026-08-27T19:16:43.430Z","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."}