{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.686","julian_year":2026.686,"time":"2026-09-08T10:19:30.232Z","years_from_j2000":26.686,"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":"ugc-4253","name":"UGC 4253","class":"spiral_galaxy_sa","category":"galaxy","object_type":"Spiral galaxy SA","mag":14.249,"mag_band":"B","abs_mag":-20.336102740248755,"abs_mag_band":"B","distance_ly":269430292.9151035,"distance_method":"luminosity distance from a spectroscopic redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":122.316216,"dec_deg":-0.366611,"epoch_ra_deg":122.659606,"epoch_dec_deg":-0.445011,"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":"Monoceros","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ugc-4253","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.249,"h_mag":11.129,"j_mag":11.915,"k_mag":10.832,"redshift":0.01799,"hubble_type":"SA","redshift_cmb":0.0190143635374762,"uncertainties":{"distance_ly":[14306909.739966344,14309887.668422677],"stellar_mass_solar":[5604891040.784562,5604891040.784562]},"major_axis_arcmin":2.54842,"minor_axis_arcmin":0.752039,"morphology_source":"SIMBAD (2019MNRAS.488..590B, quality C)","position_angle_deg":97,"stellar_mass_solar":12143930588.36655},"designations":[{"catalog":"2MASX","designation":"2MASX 08091589-0021597"},{"catalog":"PGC","designation":"PGC 22883"},{"catalog":"WISExSCOS","designation":"WISExSCOS J080915.92-002200.1"}],"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."}