{"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":"2026-11-05T14:49:39.751Z","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-31592","name":"98 Tau","class":"a0v_white_main_sequence_star","category":"star","object_type":"A0V white main-sequence star","mag":5.79,"mag_band":"V","abs_mag":1.088,"abs_mag_band":"V","distance_ly":284.35617634856555,"distance_method":"parallax","ra_deg":74.53913161966383,"dec_deg":25.050405,"epoch_ra_deg":74.952949,"epoch_dec_deg":25.091662,"epoch_moved_arcsec":1.459,"pm_ra_mas_yr":26.23,"pm_dec_mas_yr":-47.62,"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-31592","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":"04582+2503","age_years":342775170,"companions":[{"measured":2022,"magnitude":14,"components":"AD","discoverer_code":"SMR  78","separation_arcsec":28,"position_angle_deg":109},{"measured":2022,"magnitude":13.3,"components":"AB","discoverer_code":"BU 1390","separation_arcsec":45.3,"position_angle_deg":358},{"measured":2015,"magnitude":11.16,"components":"AC","discoverer_code":"BU 1390","separation_arcsec":93.6,"position_angle_deg":291}],"mass_solar":2.486,"radius_solar":2.396,"spectral_type":"A0V","uncertainties":{"distance_ly":[10.505176955279007,11.343305307105451]},"color_index_bv":0.018,"luminosity_solar":31.97422303204927,"radial_velocity_km_s":26,"spectral_type_source":"SIMBAD (1954ArA.....1..425A, quality E)","surface_gravity_log_g":4.111,"surface_temperature_k":9955,"proper_motion_ra_mas_yr":26.23,"proper_motion_dec_mas_yr":-47.62,"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","bolometric_luminosity_solar":50.6688},"designations":[{"catalog":"Bayer/Flamsteed","designation":"98 Tau"},{"catalog":"HD","designation":"HD 31592"},{"catalog":"HIP","designation":"HIP 23088"},{"catalog":"HR","designation":"HR 1590"}],"updated_at":"2026-11-04T19:31:31.075Z","citation":{"plain":"SpaceCatalog. 98 Tau [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-31592","bibtex":"@misc{spacecatalog_hd-31592,\n  author       = {{SpaceCatalog}},\n  title        = {{98 Tau}},\n  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},\n  year         = {2026},\n  url          = {https://spacecatalog.org/object/hd-31592},\n  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from HYG Database v4.1.}\n}","url":"https://spacecatalog.org/object/hd-31592","release":"DR1","doi":null},"references":[{"bibcode":"1954ArA.....1..425A","ads_url":"https://ui.adsabs.harvard.edu/abs/1954ArA.....1..425A/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."}