{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.681","julian_year":2026.681,"time":"2026-09-06T15:08:41.233Z","years_from_j2000":26.681,"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-170181","name":"PGC 170181","class":"galaxy","category":"galaxy","object_type":"Galaxy","mag":15.04,"mag_band":"B","abs_mag":-18.5951910421511,"abs_mag_band":"B","distance_ly":173965882.14747468,"distance_method":"luminosity distance from a spectroscopic redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":178.854996,"dec_deg":-10.284554,"epoch_ra_deg":179.198326,"epoch_dec_deg":-10.434055,"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":"Crater","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/pgc-170181","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":15.04,"h_mag":12.844,"j_mag":13.493,"k_mag":12.445,"redshift":0.0119,"redshift_cmb":0.0123384838607024,"uncertainties":{"distance_ly":[9004125.302446466,9005491.732277218],"stellar_mass_solar":[653931421.3916461,653931421.3916461]},"stellar_mass_solar":1307862842.7832923},"designations":[{"catalog":"2MASX","designation":"2MASX 11552519-1017043"},{"catalog":"PGC","designation":"PGC 170181"},{"catalog":"WISExSCOS","designation":"WISExSCOS J115525.26-101703.3"}],"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."}