J/ApJ/940/L26ivo://CDS.VizieR/J/ApJ/940/L26doi:10.26093/cds/vizier.19409026CDSTelesco C.M.Varosi F.Wright C.Draine B.T.Fernandez Acosta S.J.,Packham C.2025-02-24T20:13:39Z2024-12-13T09:38:00ZCDS support team

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

cds-question@unistra.frgiant-starspolarimetryinfrared-astronomyspectroscopyinterstellar-mediumWe present the first mid-IR detection of the linear polarization toward the star CygOB2-12, a luminous blue hypergiant that, with A_V_~10mag of foreground extinction, is a benchmark in the study of the properties of dust in the diffuse interstellar medium. The 8-13{mu}m spectropolarimetry, obtained with the CanariCam multimode camera at the Gran Telescopio CANARIAS shows clear trends with wavelength characteristic of silicate grains aligned in the interstellar magnetic field. The maximum polarization, detected with 7.8{sigma} statistical significance near 10.2{mu}m, is (1.24+/-0.28)% with position angle 126{deg}+/-8{deg}. We comment on these measurements in the context of recent models for the dust composition in the diffuse interstellar medium.2022ApJ...940L..26Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/940/L26CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/mk : Catalogue of Stellar Spectral Classifications (Skiff, 2009-)II/225 : Catalog of Infrared Observations, Edition 5 (Gezari+ 1999)VIII/99 : Catalogue of Radio Stars (Wendker, 2001)J/AJ/101/1408 : Massive stars in Cyg OB2. (Massey+ 1991)J/A+A/281/161 : Radio emission from stars at 250GHz (Altenhoff+, 1994)J/A+A/390/1033 : The ISO-SWS post-helium atlas (Vandenbussche+, 2002)J/AZh/81/1104 : Optical spectrum of Cyg OB2 No. 12 (Klochkova+, 2004)J/ApJS/151/299 : Spectra classification from ISO PHT-S database (Hodge+, 2004)J/ApJ/664/1102 : Radial velocity survey of Cyg OB2 association (Kiminki+, 2007)J/BaltA/17/125 : Interstellar reddening in 3 HII regions (Straizys+, 2008)J/AJ/137/3358 : Speckle interferometry of massive stars (Mason+, 2009)J/ApJ/708/1628 : Diffuse interstellar bands. IV. (McCall+, 2010)J/ApJ/713/871 : Sources in star-forming reg Cyg-OB2 from X-ray (Wright+, 2010)J/A+A/536/A31 : Cyg OB2 XMM observations (Rauw, 2011)J/ApJ/751/4 : Radial velocities of massive stars in Cyg OB2 (Kiminki+, 2012)J/MNRAS/449/741 : The massive star population of Cygnus OB2 (Wright+, 2015)J/A+A/598/A108 : Variability survey of brightest stars (Laur+, 2017)J/ApJ/850/194 : Equivalent widths of 8 DIBs for 186 O & B stars (Fan+, 2017)J/MNRAS/484/1838 : Spatial substructure of Cygnus OB2 (Berlanas+, 2019)J/ApJ/895/38 : MIR extinction toward Cyg OB2-12 ISM (Hensley+, 2020)J/A+A/637/A64 : Cygnus OB2 e-MERLIN 21cm survey (COBRaS) (Morford+, 2020)J/AJ/160/115 : JHK obs. of 75 OB stars in Cyg OB2 (Caballero-Nieves+, 2020)J/MNRAS/493/2339 : Internal motions in OB-associations (Melnik+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/940/L26https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/940/L26http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/940/L26https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/940/L26https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/940/L26http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/940/L26GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapInfrareddefaultJ/ApJ/940/L26/fig1CanariCam 8-13um intensity spectrumrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[7.76/12.96] Wavelengthumem.wlfloatFlux[5.3/17.2] Flux densityJyphot.flux.density;em.IR.8-15umfloatSNR[101/732] Signal-to-Noisestat.snrintqJ/ApJ/940/L26/fig2CanariCam 8-13um spectropolarimetry of CygOB2-12e_q