J/ApJ/939/32ivo://CDS.VizieR/J/ApJ/939/32doi:10.26093/cds/vizier.19390032CDSHrivnak B.J.Lu W.Bakke W.C.Grimm P.J.2025-02-12T20:09:29Z2024-10-25T09:18:49ZCDS support team

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

cds-question@unistra.frplanetary-nebulaevisible-astronomybroad-band-photometrygiant-starsf-starsWe have carried out a new photometric V,R_C_ study of 12 protoplanetary nebulae, objects in the short-lived transition between the asymptotic giant branch and planetary nebula phases of stellar evolution. These had been the subjects of an earlier study, using data from 1994-2007, that found that all 12 varied periodically, with pulsation periods in the range of ~38 to ~150 days. They are all carbon-rich, with F-G spectral types. We combined our new (2008-2018) data with publicly available All-Sky Automated Survey for Supernovae data and determined new periods for their variability. The older and newer period values were compared to investigate evidence of period change, for which there is theoretical support that it might be detectable in a decade or two in some cases. Such a detection is challenging since the light curves are complicated, with multiple periods, changing amplitudes, and evidence of shocks. Nevertheless, we found one, and possibly two, such cases, which are associated with the higher-temperature stars in the sample (7250 and 8000 K). These results are most consistent with the evolution of stars at the lower end of the mass range of carbon stars, ~1.5-2M_{sun}_. Several of the stars show longer-term trends of increasing (six cases) or decreasing (one case) brightness, which we think is most likely due to changes in the circumstellar dust opacity. There is one case of a possible ~1.8yr period in addition to the shorter pulsation. This is interpreted as possible evidence of an orbiting companion.2022ApJ...939...32Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/939/32CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/118 : UBVRI standards around Celestial Equator (Landolt 1983)II/183 : UBVRI Photometric Standards (Landolt 1992)J/A+A/267/515 : Very cold C-rich circumstellar envelopes (Omont+ 1993)J/ApJS/92/125 : Post-AGB evolution (Vassiliadis+, 1994)J/A+A/299/755 : Stellar evolution. II. Post-AGB (Bloecker+, 1995)J/other/PZ/29.1 : UBV light curves of V354 Lac (Arkhipova+, 2009)J/ApJ/709/1042 : Variability in C-rich proto-PNe. (Hrivnak+, 2010)J/ApJ/766/116 : Variability in proto-PNe. II. (Hrivnak+, 2013)J/A+A/587/A6 : Linelist of 14 Galactic post-AGB stars (De Smedt+, 2016)J/A+A/588/A25 : Post-AGB/CSPNe evolutionary models (Miller Bertolami, 2016)J/ApJ/826/44 : Spitzer/IRS obs. of Magellanic carbon stars (Sloan+, 2016)J/AJ/159/21 : V and Rc light curves of medium-bright PPNe (Hrivnak+, 2020)J/MNRAS/508/2226 : Binary central star of V510 Pup (Manick+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/939/32https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/939/32http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/939/32https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/939/32https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/939/32http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/939/32GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/939/32/table1 (*List of C-rich protoplanetary nebulae (PPNs) observed)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/939/32/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/939/32/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/939/32/table1?GETtext/xml+votable180.050000true36.67416762.3561110.0055555555555555566/1229 3649 13297 13917 14256 14323 14453 22392 22425 23695 24079 48822https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/939/32?format=asciiOpticaldefaultJ/ApJ/939/32/table1*List of C-rich protoplanetary nebulae (PPNs) observed2MASS2MASS identifiermeta.id.crosscharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameIRAS identifier; except flaggedmeta.id;meta.maincharprimaryf_NameFlag on Name (1)meta.codecharDEJ20002MASS degree of declination (J2000)pos.eq.dec;meta.mainSimbadSimbad column added by the CDSmeta.ref.urlcharGLON[24/208.9] Galactic longitudedegpos.galactic.lonGLAT[-21/17.1] Galactic latitudedegpos.galactic.latfloatVmag[8.2/14.2] V magnitude (2)magphot.mag;em.opt.VfloatB-V[0.5/2.8]? B-V color index (2)magphot.color;em.opt.B;em.opt.VfloatnullableSpTSpectral typesrc.spTypecharONameOther name(s)meta.idcharNpNumber of photometry measurements for this PPN (link to Table 3)meta.numberintnullableLCInteractive LC Plotmeta.ref.urlcharGaia? Gaia identifiermeta.id.crossnullablef_Gaiae: not included in the Gaia catalogmeta.codecharRAJ20002MASS hour of right ascension (J2000)pos.eq.ra;meta.mainJ/ApJ/939/32/table3Differential standard BVRc magnitudes for the program objects from 2008-2018recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameProgram Object Name (as in Table 1)meta.id;meta.maincharHJDV[54657.8/58334.74]? Heliocentric Julian Date, V band observation; HJDV-2400000dtime.epochdoublenullableDelV[-2.8/1.72]? Differential magnitude in Vmagphot.mag;arith.diff;em.opt.VfloatnullableHJDRc[54654.7/58334.74]? Heliocentric Julian Date, Rc band observation; HJDRc-2400000dtime.epochdoublenullableDelRc[-3.12/1.01]? Differential magnitude in Rcmagphot.mag;arith.diff;em.opt.RfloatnullableHJDB[54657.8/58334.75]? Heliocentric Julian Date, B band observation; HJD-2400000dtime.epochdoublenullableDelB[-2.9/-0.6]? Differential Magnitude in Bmagphot.mag;arith.diff;em.opt.Bfloatnullable