{"id":1833,"slug":"hat-p-21-b","name":"HAT-P-21 b","domain":"exoplanet","class":"exoplanet","otype":"Pl","otype_label":"Planet","ra":171.2749348,"dec":41.0280207,"coo_err_mas":0.0136,"coo_bibcode":"2020yCat.1350....0G","plx_mas":3.519,"pmra":-1.142,"pmdec":13.523,"rv_kms":null,"redshift":null,"dist_pc":277.278,"vmag":11.459,"bmag":null,"gmag":null,"jmag":null,"kmag":null,"sp_type":null,"morph_type":null,"size_maj":null,"size_min":null,"size_angle":null,"nbref":47,"simbad_oid":5415778,"gaia_dr3":null,"jpl_spkid":null,"ned_name":null,"exo_name":"HAT-P-21 b","host_object_id":2634992,"depth":0,"deep_at":null,"views":1,"first_seen":"2026-08-14T16:25:51.971135+00:00","updated_at":"2026-09-13T03:31:17.289698+00:00","identifiers":["HAT-P-21b"],"measurements":[{"parameter":"eccentricity","value":0.228,"value_text":null,"unit":null,"err_plus":0.016,"err_minus":0.016,"band":null,"method":"Transit","source":"nasa-exo","reference":"Kokori et al. 2023","ref_year":2023},{"parameter":"eccentricity","value":0.23,"value_text":null,"unit":null,"err_plus":0.02,"err_minus":0.02,"band":null,"method":"Transit","source":"nasa-exo","reference":"Stassun et al. 2017","ref_year":2017},{"parameter":"eccentricity","value":0.217,"value_text":null,"unit":null,"err_plus":0.01,"err_minus":0.01,"band":null,"method":"Transit","source":"nasa-exo","reference":"Bonomo et al. 2017","ref_year":2017},{"parameter":"eccentricity","value":0.228,"value_text":null,"unit":null,"err_plus":0.016,"err_minus":0.016,"band":null,"method":"Transit","source":"nasa-exo","reference":"Bakos et al. 2010","ref_year":2010},{"parameter":"equilibrium_temperature","value":1367.0,"value_text":null,"unit":"K","err_plus":27.0,"err_minus":27.0,"band":null,"method":"Transit","source":"nasa-exo","reference":"Mancini et al. 2022","ref_year":2022},{"parameter":"equilibrium_temperature","value":1289.0,"value_text":null,"unit":"K","err_plus":null,"err_minus":null,"band":null,"method":"Transit","source":"nasa-exo","reference":"ExoFOP","ref_year":2010},{"parameter":"equilibrium_temperature","value":1283.0,"value_text":null,"unit":"K","err_plus":50.0,"err_minus":50.0,"band":null,"method":"Transit","source":"nasa-exo","reference":"Bakos et al. 2010","ref_year":2010},{"parameter":"mass","value":1344.41416161,"value_text":null,"unit":"M_earth","err_plus":50.85254512,"err_minus":50.85254512,"band":null,"method":"Transit","source":"nasa-exo","reference":"Mancini et al. 2022","ref_year":2022},{"parameter":"mass","value":1547.8321,"value_text":null,"unit":"M_earth","err_plus":498.9931,"err_minus":498.9931,"band":null,"method":"Transit","source":"nasa-exo","reference":"Stassun et al. 2017","ref_year":2017},{"parameter":"mass","value":1261.7851,"value_text":null,"unit":"M_earth","err_plus":41.3179,"err_minus":41.3179,"band":null,"method":"Transit","source":"nasa-exo","reference":"Bonomo et al. 2017","ref_year":2017},{"parameter":"mass","value":1291.289,"value_text":null,"unit":"M_earth","err_plus":51.168,"err_minus":51.168,"band":null,"method":"Transit","source":"nasa-exo","reference":"Bakos et al. 2010","ref_year":2010},{"parameter":"orbital_period","value":4.12448852,"value_text":null,"unit":"d","err_plus":6.9e-07,"err_minus":6.9e-07,"band":null,"method":"Transit","source":"nasa-exo","reference":"Kokori et al. 2023","ref_year":2023},{"parameter":"orbital_period","value":4.12448799,"value_text":null,"unit":"d","err_plus":9.6e-07,"err_minus":9.6e-07,"band":null,"method":"Transit","source":"nasa-exo","reference":"Ivshina &amp; Winn 2022","ref_year":2022},{"parameter":"orbital_period","value":4.12449009,"value_text":null,"unit":"d","err_plus":9e-07,"err_minus":9e-07,"band":null,"method":"Transit","source":"nasa-exo","reference":"Mancini et al. 2022","ref_year":2022},{"parameter":"orbital_period","value":4.1244799,"value_text":null,"unit":"d","err_plus":6.3e-06,"err_minus":6.3e-06,"band":null,"method":"Transit","source":"nasa-exo","reference":"Patel &amp; Espinoza 2022","ref_year":2022},{"parameter":"orbital_period","value":4.124481,"value_text":null,"unit":"d","err_plus":7e-06,"err_minus":7e-06,"band":null,"method":"Transit","source":"nasa-exo","reference":"Bonomo et al. 2017","ref_year":2017},{"parameter":"orbital_period","value":4.12448,"value_text":null,"unit":"d","err_plus":7e-06,"err_minus":7e-06,"band":null,"method":"Transit","source":"nasa-exo","reference":"Stassun et al. 2017","ref_year":2017},{"parameter":"orbital_period","value":4.1244833,"value_text":null,"unit":"d","err_plus":4.4e-06,"err_minus":4.4e-06,"band":null,"method":"Transit","source":"nasa-exo","reference":"ExoFOP","ref_year":2010},{"parameter":"orbital_period","value":4.124481,"value_text":null,"unit":"d","err_plus":7e-06,"err_minus":7e-06,"band":null,"method":"Transit","source":"nasa-exo","reference":"Bakos et al. 2010","ref_year":2010},{"parameter":"radius","value":12.66614819,"value_text":null,"unit":"R_earth","err_plus":0.6389119,"err_minus":0.6389119,"band":null,"method":"Transit","source":"nasa-exo","reference":"Mancini et al. 2022","ref_year":2022},{"parameter":"radius","value":12.44199,"value_text":null,"unit":"R_earth","err_plus":1.79344,"err_minus":1.79344,"band":null,"method":"Transit","source":"nasa-exo","reference":"Stassun et al. 2017","ref_year":2017},{"parameter":"radius","value":11.478016,"value_text":null,"unit":"R_earth","err_plus":1.031228,"err_minus":1.031228,"band":null,"method":"Transit","source":"nasa-exo","reference":"Bonomo et al. 2017","ref_year":2017},{"parameter":"radius","value":11.478,"value_text":null,"unit":"R_earth","err_plus":1.031,"err_minus":1.031,"band":null,"method":"Transit","source":"nasa-exo","reference":"Bakos et al. 2010","ref_year":2010},{"parameter":"radius","value":12.4249,"value_text":null,"unit":"R_earth","err_plus":0.670575,"err_minus":0.670575,"band":null,"method":"Transit","source":"nasa-exo","reference":"ExoFOP","ref_year":2010},{"parameter":"semi_major_axis","value":0.05037,"value_text":null,"unit":"au","err_plus":0.00067,"err_minus":0.00067,"band":null,"method":"Transit","source":"nasa-exo","reference":"Mancini et al. 2022","ref_year":2022},{"parameter":"semi_major_axis","value":0.0495,"value_text":null,"unit":"au","err_plus":0.00072,"err_minus":0.00075,"band":null,"method":"Transit","source":"nasa-exo","reference":"Bonomo et al. 2017","ref_year":2017},{"parameter":"semi_major_axis","value":0.0494,"value_text":null,"unit":"au","err_plus":0.0007,"err_minus":0.0007,"band":null,"method":"Transit","source":"nasa-exo","reference":"Bakos et al. 2010","ref_year":2010}],"orbit":null,"exoplanet":{"object_id":1833,"pl_name":"HAT-P-21 b","hostname":"HAT-P-21","sy_pnum":1,"disc_method":"Transit","disc_year":2010,"disc_facility":"HATNet","orbper_d":4.12448,"orbsmax_au":0.05037,"rade":12.44199,"radj":1.11,"masse":1547.8321,"massj":4.87,"dens_gcm3":3.633781,"eccen":0.23,"insol":459.542,"eqt_k":1367.0,"st_teff":5588.0,"st_rad":1.21,"st_mass":1.24,"st_spectype":"G3","sy_dist_pc":277.278,"updated_at":"2026-09-13T03:31:17.289698+00:00"},"sources":[]}