{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.839","julian_year":2026.839,"time":"2026-11-03T09:26:34.998Z","years_from_j2000":26.839,"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-25604","name":"37 Tau","class":"k0iii_iiib_orange_giant","category":"star","object_type":"K0III-IIIb orange giant","mag":4.36,"mag_band":"V","abs_mag":0.566,"abs_mag_band":"V","distance_ly":187.12341549278318,"distance_method":"parallax","ra_deg":61.173795,"dec_deg":22.081926,"epoch_ra_deg":61.573715,"epoch_dec_deg":22.155378,"epoch_moved_arcsec":2.92,"pm_ra_mas_yr":91.73,"pm_dec_mas_yr":-58.52,"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-25604","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":"04047+2205","companions":[{"measured":2013,"magnitude":10.01,"components":"AC","discoverer_code":"STT 558","separation_arcsec":135,"position_angle_deg":194},{"measured":2013,"magnitude":12.62,"components":"AD","discoverer_code":"STG   4","separation_arcsec":235.8,"position_angle_deg":216}],"spectral_type":"K0III-IIIb","uncertainties":{"metallicity_fe_h":[0.059,0.059]},"color_index_bv":1.064,"luminosity_solar":51.713031791696295,"metallicity_fe_h":0.08,"radial_velocity_km_s":9,"spectral_type_source":"SIMBAD (1989ApJS...71..245K, quality B)","surface_gravity_log_g":2.74,"surface_temperature_k":4783,"metallicity_fe_h_source":"Median of 8 spectroscopic determinations in 11 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":91.73,"proper_motion_dec_mas_yr":-58.52,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"Bayer/Flamsteed","designation":"37 Tau"},{"catalog":"HD","designation":"HD 25604"},{"catalog":"HIP","designation":"HIP 19038"},{"catalog":"HR","designation":"HR 1256"}],"updated_at":"2026-10-01T09:42:28.932Z","citation":{"plain":"SpaceCatalog. 37 Tau [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-25604","bibtex":"@misc{spacecatalog_hd-25604,\n  author       = {{SpaceCatalog}},\n  title        = {{37 Tau}},\n  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},\n  year         = {2026},\n  url          = {https://spacecatalog.org/object/hd-25604},\n  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from HYG Database v4.1.}\n}","url":"https://spacecatalog.org/object/hd-25604","release":"DR1","doi":null},"references":[{"bibcode":"1989ApJS...71..245K","ads_url":"https://ui.adsabs.harvard.edu/abs/1989ApJS...71..245K/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."}