{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.672","julian_year":2026.672,"time":"2026-09-03T12:54:55.538Z","years_from_j2000":26.672,"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":"ngc-3101","name":"NGC 3101","class":"spiral_galaxy_sa","category":"galaxy","object_type":"Spiral galaxy Sa","mag":15.37,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":287290526.34796166,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":150.397625,"dec_deg":-2.9944166666666665,"epoch_ra_deg":150.737644,"epoch_dec_deg":-3.123486,"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":"Sextans","discovered":"1865","featured":false,"url":"https://spacecatalog.org/object/ngc-3101","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":15.37,"h_mag":11.28,"j_mag":12.08,"k_mag":11.04,"redshift":0.01906,"hubble_type":"Sa","wikidata_id":"Q1102960","redshift_cmb":0.020256146267215724,"discovered_by":"Albert Marth","ngc_type_code":"G","uncertainties":{"distance_ly":[18313475.0345199,18313475.0345199]},"major_axis_arcmin":1.22,"minor_axis_arcmin":0.21,"position_angle_deg":150,"surface_brightness":23.8,"radial_velocity_km_s":5660},"designations":[{"catalog":"2MASX","designation":"2MASX J10013544-0259400"},{"catalog":"LEDA","designation":"LEDA 29025"},{"catalog":"MCG","designation":"MCG +00-26-011"},{"catalog":"NGC","designation":"NGC 3101"},{"catalog":"PGC","designation":"PGC 29025"},{"catalog":"SDSS","designation":"SDSS J100135.43-025939.9"}],"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."}