{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.845","julian_year":2026.845,"time":"2026-11-05T14:49:20.415Z","years_from_j2000":26.845,"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-29589","name":"93 Tau","class":"b8iv_blue_white_subgiant","category":"star","object_type":"B8IV blue-white subgiant","mag":5.45,"mag_band":"V","abs_mag":-0.081,"abs_mag_band":"V","distance_ly":416.54703008078394,"distance_method":"parallax","ra_deg":70.01424,"dec_deg":12.197609,"epoch_ra_deg":70.390729,"epoch_dec_deg":12.250439,"epoch_moved_arcsec":0.35,"pm_ra_mas_yr":-1.29,"pm_dec_mas_yr":-12.98,"position_epoch_jyear":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Taurus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-29589","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":{"wds_id":"04401+1212","companions":[{"measured":1999,"magnitude":17.3,"components":null,"discoverer_code":"HUB   4","separation_arcsec":10,"position_angle_deg":251}],"mass_solar":3.422,"radius_solar":2.766,"spectral_type":"B8IV","uncertainties":{"distance_ly":[16.35522347888928,17.749010832616253]},"color_index_bv":-0.121,"luminosity_solar":93.84259312370172,"radial_velocity_km_s":23,"spectral_type_source":"SIMBAD (quality C)","surface_gravity_log_g":3.728,"surface_temperature_k":9999,"proper_motion_ra_mas_yr":-1.29,"proper_motion_dec_mas_yr":-12.98,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: above 7,500 K GSP-Phot's temperature and extinction are degenerate; Gaia's temperature, radius and luminosity do not agree with one another","bolometric_luminosity_solar":173.0153},"designations":[{"catalog":"Bayer/Flamsteed","designation":"93 Tau"},{"catalog":"HD","designation":"HD 29589"},{"catalog":"HIP","designation":"HIP 21735"},{"catalog":"HR","designation":"HR 1484"}],"updated_at":"2026-11-04T21:40:42.974Z","citation":{"plain":"SpaceCatalog. 93 Tau [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-29589","bibtex":"@misc{spacecatalog_hd-29589,\n  author       = {{SpaceCatalog}},\n  title        = {{93 Tau}},\n  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},\n  year         = {2026},\n  url          = {https://spacecatalog.org/object/hd-29589},\n  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from HYG Database v4.1.}\n}","url":"https://spacecatalog.org/object/hd-29589","release":"DR1","doi":null},"references":[],"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."}