{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.665","julian_year":2026.665,"time":"2026-08-31T21:58:37.278Z","years_from_j2000":26.665,"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-56221","name":"PGC 56221","class":"elliptical_galaxy","category":"galaxy","object_type":"Elliptical galaxy","mag":14.728,"mag_band":"B","abs_mag":-20.21422011072781,"abs_mag_band":"B","distance_ly":317592250.9359733,"distance_method":"luminosity distance from a spectroscopic redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":237.750687,"dec_deg":81.776382,"epoch_ra_deg":237.235522,"epoch_dec_deg":81.694104,"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 Minor","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/pgc-56221","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.728,"h_mag":11.351,"j_mag":12.073,"k_mag":11.014,"redshift":0.02188,"hubble_type":"-4.9","redshift_cmb":0.0223578660802561,"uncertainties":{"distance_ly":[17383908.17597985,17388321.983248275],"stellar_mass_solar":[9341288760.860155,9341288760.860155]},"major_axis_arcmin":0.81106,"minor_axis_arcmin":0.617217,"morphology_source":"SIMBAD (2001ApJ...560..566K, quality D)","position_angle_deg":55,"stellar_mass_solar":28023866282.580463},"designations":[{"catalog":"2MASX","designation":"2MASX 15510016+8146349"},{"catalog":"PGC","designation":"PGC 56221"},{"catalog":"WISExSCOS","designation":"WISExSCOS J155100.28+814635.4"}],"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":"2026-08-30T09:56:50.739Z","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."}