{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.678","julian_year":2026.678,"time":"2026-09-05T15:20:36.982Z","years_from_j2000":26.678,"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":"eso-581-004","name":"ESO 581-004","class":"spiral_galaxy","category":"galaxy","object_type":"Spiral galaxy","mag":13.31,"mag_band":"B","abs_mag":-20.32091076772179,"abs_mag_band":"B","distance_ly":173623308.91509724,"distance_method":"luminosity distance from a photometric redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":224.374374,"dec_deg":-18.453358,"epoch_ra_deg":224.753113,"epoch_dec_deg":-18.561505,"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":"Libra","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/eso-581-004","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":13.31,"h_mag":13.135,"j_mag":13.725,"k_mag":12.87,"redshift":0.0120012960006,"hubble_type":"6.0","redshift_cmb":0.0123144091597451,"uncertainties":{"distance_ly":[35138260.53121781,35255883.16941943],"stellar_mass_solar":[560512724.2467792,560512724.2467792]},"major_axis_arcmin":0.52,"minor_axis_arcmin":0.156,"morphology_source":"SIMBAD (1989ESOLV.C......0L, quality D)","position_angle_deg":15,"stellar_mass_solar":1027606661.1190953},"designations":[{"catalog":"2MASX","designation":"2MASX 14572984-1827120"},{"catalog":"PGC","designation":"PGC 53456"},{"catalog":"WISExSCOS","designation":"WISExSCOS J145729.86-182711.1"}],"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."}