{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.843","julian_year":2026.843,"time":"2026-11-05T01:21:38.278Z","years_from_j2000":26.843,"frame":"date","applied":"Proper motion, then precession and nutation. The catalogued position is carried along the great circle the object's own published motion puts it on, at a constant velocity, from the epoch that position was measured at, 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. The motion runs from position_epoch_jyear where the upstream publishes one — a timed pulsar's position belongs to the year it was timed — and from J2000 where it does not. 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":"hd-212957","name":"HD 212957","class":"a3_white_star","category":"star","object_type":"A3 white star","mag":9.05,"mag_band":"V","abs_mag":1.031,"abs_mag_band":"V","distance_ly":1310.0399613951738,"distance_method":"parallax (Gaia DR3, zero point corrected)","ra_deg":336.51005284183276,"dec_deg":65.503367,"epoch_ra_deg":336.72065,"epoch_dec_deg":65.640581,"epoch_moved_arcsec":0.487,"pm_ra_mas_yr":15.4,"pm_dec_mas_yr":9.59,"position_epoch_jyear":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Cepheus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-212957","source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0","attribution":"HYG Database v4.1, Astronexus (github.com/astronexus/HYG-Database). Fields derived from it stay under CC BY-SA 4.0.","commercial_use":"allowed"},"radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"age_years":376990620,"mass_solar":3,"radius_solar":11.537,"spectral_type":"A3","uncertainties":{"distance_ly":[7.056889532891943,7.133745283718711]},"color_index_bv":1.153,"luminosity_solar":33.70678545077748,"spectral_type_source":"SIMBAD (1993yCat.3135....0C, quality E)","surface_gravity_log_g":2.61,"surface_temperature_k":5135,"proper_motion_ra_mas_yr":15.4,"proper_motion_dec_mas_yr":9.59,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: GSP-Phot's temperature is outside any the star's spectral class allows","bolometric_luminosity_solar":83.4616},"designations":[{"catalog":"HD","designation":"HD 212957"},{"catalog":"HIP","designation":"HIP 110728"}],"updated_at":"2026-11-04T19:31:31.075Z","citation":{"plain":"SpaceCatalog. HD 212957 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-212957","bibtex":"@misc{spacecatalog_hd-212957,\n  author       = {{SpaceCatalog}},\n  title        = {{HD 212957}},\n  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},\n  year         = {2026},\n  url          = {https://spacecatalog.org/object/hd-212957},\n  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from HYG Database v4.1.}\n}","url":"https://spacecatalog.org/object/hd-212957","release":"DR1","doi":null},"references":[{"bibcode":"1993yCat.3135....0C","ads_url":"https://ui.adsabs.harvard.edu/abs/1993yCat.3135....0C/abstract","quantity":"properties.spectral_type_source"}],"attribution":"Data from SpaceCatalog.org. Each record names its upstream in `source`, with that producer's terms in `source.license`, the acknowledgement it asks for in `source.attribution`, and whether its terms allow commercial use in `source.commercial_use`; those terms govern the record, and citing SpaceCatalog does not discharge them."}