J/A+A/690/A10ivo://CDS.VizieR/J/A+A/690/A10doi:10.26093/cds/vizier.36900010CDSBerdyugin A.Landstreet J.D.Bagnulo S.Piirola V.Berdyugin S.V.2025-02-24T20:01:17Z2024-09-25T08:10:12ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frwhite-dwarf-starsmagnetic-fieldsAbout 20% of white dwarfs possess a magnetic field that may be detected by the splitting and/or polarisation of their spectral lines. As they cool, white dwarfs evolve to such a low effective temperature that no spectral lines can be seen in the visible wavelength range. If their atmosphere is not polluted by the debris of a planetary system, such cool white dwarfs have featureless optical spectra. Until quite recently, very little was known about the incidence of magnetic fields in such objects. However, when observed with polarimetric techniques, a significant number of featureless white dwarfs reveal the presence of a strong magnetic field in their optical continuum spectra. Measuring the occurrence rate and strength of magnetic fields in old white dwarfs may help to understand how these fields are generated and evolve. Here we report the results of an ongoing survey of cool white dwarfs with the high precision broad-band polarimeter DIPOL-UF deployed at the Nordic Optical Telescope, La Palma, Spain. This survey has so far led to the firm discovery of 13 cool magnetic white dwarfs in the solar neighborhood, including six new detections reported in this paper.2024A&A...690A..10Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/690/A10CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/wd : Spectroscopically identified white dwarfs (McCook+, 2014)J/ApJ/901/93 : Model atmosphere analysis of hot WDs from SDSS DR12J/MNRAS/508/3877 : Catalogue of white dwarfs in Gaia EDR3 (Gentile+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/690/A10https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/690/A10http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/690/A10https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/690/A10https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/690/A10http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/690/A10GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/690/A10/table1Basic parameters of stars observedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar name according to McCook & Sion, WDHHMM+DDd (1999ApJS..121....1M, Cat. B/wd)meta.id;meta.maincharf_Name[*] A "*" in this column means that the star was newly discovered magneticmeta.codecharSNameSimabd main identifiedmeta.idcharGmagG magnitudemagphot.mag;em.optfloatddistancepcpos.distancefloatTeffEffective temperature from Gentile Fusillo et al. (2021MNRAS.508.3877G, Cat. J/MNRAS/508/3877)Kphys.temperature.effectiveintMassMass from Gentile Fusillo et al. (2021MNRAS.508.3877G, Cat. J/MNRAS/508/3877solMassphys.massfloatAgeAge interpolated from the cooling tables by Bedard et al. (2020ApJ...901...93B, Cat. J/ApJ/901/93)Gyrtime.agefloatCompMain atmospheric compositionmeta.notecharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/690/A10/table2Observing log of WDse_CP(V)Uncertainty of the circular polarisation in % in the V' filter%stat.errorfloatf_Name[*] A "*" in this column means that there is a definite detectionmeta.codecharJDJulian date of the observation (JD-2400000)dtime.epochdoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar name according to McCook & Sioni, WDHHMM+DDd (1999ApJS..121....1M, Cat. B/wd)meta.id;meta.maincharExpTimeExposure time of the observationstime.duration;obs.exposureintCP(B)Circular polarisation in % in the B filter%phys.polarization.circularfloate_CP(B)Uncertainty of the circular polarisation in % in the B' filter%stat.errorfloatCP(V)Circular polarisation in % in the B filter%phys.polarization.circularfloatCP(R)Circular polarisation in % in the B filter%phys.polarization.circularfloate_CP(R)Uncertainty of the circular polarisation in % in the R' filter%stat.errorfloatObs.dateDate of the observationstime.epochnullable