J/A+A/538/A76ivo://CDS.VizieR/J/A+A/538/A76doi:10.26093/cds/vizier.35380076CDSNavarro S.G.Corradi R.L.M.Mampaso A.2017-10-16T14:57:41Z2012-07-24T06:57:52ZCDS support team

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

cds-question@unistra.frplanetary-nebulaemorgan-keenan-classificationAs part of a project aimed at deriving extinction-distances for thirty-five planetary nebulae, spectra of a few thousand stars were analyzed to determine their spectral type and luminosity class. We present here the automatic spectral classification process used to classify stellar spectra. This system can be used to classify any other stellar spectra with similar or higher signal-to-noise ratios. Spectral classification was performed using a system of artificial neural networks that were trained with a set of line-strength indices selected among the spectral lines most sensitive to temperature and the best luminosity tracers. The training and validation processes of the neural networks are discussed and the results of additional validation probes, designed to ensure the accuracy of the spectral classification, are presented.2012A&A...538A..76Nhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/538/A76CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIII/92 : A Library of Stellar Spectra (Jacoby+ 1984)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/538/A76https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/538/A76http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/538/A76https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/538/A76https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/538/A76http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/538/A76GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/538/A76/table1 (Radial velocity and S/N of the stars in the JHC (Jacoby et al., Cat. III/92) catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/538/A76/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/538/A76/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/538/A76/table1?GETtext/xml+votable180.050000true80.622094233.51401670.0055555555555555566/461 463 472 474 881 946 1031 1064 1070 1094 1098 1164 1217 1224 1287 1299 1458 1466 1686 1787 1790 2436 2466 2490 2832-2833 2942 2989 3018 3022 3027 3033 3038 3044-3045 3050 3052 3054 3064 3066 3083 3091 3137 3147 3180 3231 3247 3256-3258 3274 3296 3300-3302 3308 3342 3585 3589 3596 3600-3601 3606 3609 3613 3615 3618 3622-3623 3629 3633-3634 3642 3714 3716 3719 3786 4444 4757 4917 5026 5177 5675 7286 7978 8035 10406 10416 10553 10859 11010 12965 13037 14248 14263 14279 14297 14320-14321 14325 14359 14411 14627 14633 14692 14740 14784 21550 21939 22123 22309 22510 22840 22933 23545-23546 23867 23962 23984 24371 24377 24380 24469 24489 24499 24522 24555 27103 28147 28164 28336 28437 28482 28668 29162 29462-29463 29465 29515 29579 30566 31121 32335 36839https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/538/A76?format=asciiOpticaldefaultJ/A+A/538/A76/table1Radial velocity and S/N of the stars in the JHC (Jacoby et al., Cat. III/92) catalogNameName of the objectmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintn_JHC[*] * for stars observed also with the same instrumentation as our program starsmeta.notecharJHCJHC number (Cat. III/92) <[JHC84] NNN> in Simbadmeta.id;meta.mainintSpTJHC MK spectral classificationsrc.spTypechariSpTNumerical code for the adopted spectral type (1)meta.codeintLC[1/5] Adopted luminosity class (numeric class)src.class.luminosityintRVcorCorrected radial velocitykm/sphys.veloc;pos.heliocentricintS/NSignal-to-noise ratiostat.snrintComCommentsmeta.notecharSimbadSimbad column added by the CDSmeta.refchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.mainnullable_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainnullable