{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.682","julian_year":2026.682,"time":"2026-09-06T22:29:25.105Z","years_from_j2000":26.682,"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":"ngc4098-ned02","name":"NGC4098 NED02","class":"spiral_galaxy_sb","category":"galaxy","object_type":"Spiral galaxy Sb","mag":15.06,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":382361041.5857184,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":181.5175833333333,"dec_deg":20.603916666666667,"epoch_ra_deg":181.86102,"epoch_dec_deg":20.454346,"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":"Coma Berenices","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ngc4098-ned02","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":15.06,"redshift":0.02574,"hubble_type":"Sb","redshift_cmb":0.026829029339800137,"ngc_type_code":"G","uncertainties":{"distance_ly":[20992087.62003174,20992087.62003174]},"major_axis_arcmin":1.23,"minor_axis_arcmin":0.79,"position_angle_deg":161,"surface_brightness":23.99,"radial_velocity_km_s":7617},"designations":[{"catalog":"MCG","designation":"MCG +04-29-023 NED02"},{"catalog":"OpenNGC","designation":"NGC4098 NED02"},{"catalog":"PGC","designation":"PGC 4581802"},{"catalog":"SDSSJ","designation":"SDSSJ 120603.75+203620.0"},{"catalog":"SDSSJ","designation":"SDSSJ 120603.75+203620.1"}],"source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-4.0"},"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."}