J/AJ/159/21ivo://CDS.VizieR/J/AJ/159/21doi:10.26093/cds/vizier.51590021CDSHrivnak B.J.Henson G.Hillwig T.C.Lu W.Murphy B.W.Kaitchuck R.H.2024-10-25T20:12:05Z2020-03-23T11:59:19ZCDS support team

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

cds-question@unistra.frinfrared-photometryvisible-astronomyphotometryplanetary-nebulaecarbon-starsgiant-starsWe present 10 years of new photometric monitoring of the light variability of five evolved stars with strong mid-infrared emission from surrounding dust. Three are known carbon-rich proto-planetary nebulae (PPNe) with F-G spectral types; the nature of the other two was previously unknown. For the three PPNe, we determine or refine the pulsation periods of IRAS04296+3429 (71 days), 06530-0213 (80 days), and 23304+6147 (84 days). A secondary period was found for each, with a period ratio P_2_/P_1_ of 0.9. The light variations are small, 0.1-0.2mag. These are similar to values found in other PPNe. The other two are found to be giant stars. IRAS09296+1159 pulsates with a period of only 47 days but reaches pulsational light variations of 0.5mag. Supplemental spectroscopy reveals the spectrum of a CH carbon star. IRAS08359-1644 is a G1III star that does not display pulsational variability; rather, it shows nonperiodic decreases of brightness of up to 0.5mag over this 10 year interval. These drops in brightness are reminiscent of the light curves of R Corona Borealis variables, but with much smaller decreases in brightness and are likely due to transient dust obscuration. Its spectral energy distribution is very similar to that of the unusual oxygen-rich giant star HDE233517, which possesses mid-infrared hydrocarbon emission features. These two non-PPNe turn out to be members of the rare group of giant stars with large mid-infrared excesses due to dust, objects which presumably have interesting evolutionary histories.2020AJ....159...21Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/159/21CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/118 : UBVRI standards around Celestial Equator (Landolt 1983)II/125 : IRAS catalogue of Point Sources, Version 2.0 (Joint, 1986)II/183 : UBVRI Photometric Standards (Landolt 1992)I/305 : The Guide Star Catalog, Version 2.3.2 (GSC2.3) (Lasker+, 2006)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+, 2003)I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)J/ApJS/122/221 : A mid-IR survey of Proto-PNs Candidates (Meixner+, 1999)J/A+A/417/269 : Equivalent widths of two post-AGB stars (Reyniers+, 2004)J/A+A/458/173 : Optical spectroscopy of 253 IRAS sources (Suarez+, 2006)J/MNRAS/369/751 : Near-infrared photometry of carbon stars (Whitelock+, 2006)J/ApJ/709/1042 : Variability in C-rich proto-PNe. (Hrivnak+, 2010)J/ApJ/765/12 : Carbon stars & DQ white dwarfs from SDSS-DR7+DR8 (Green,2013)J/ApJ/766/116 : Variability in proto-PNe. II. (Hrivnak+, 2013)J/AJ/149/184 : Long-term photometry for 4 O-rich PPNe (Hrivnak+, 2015)J/AJ/150/123 : Catalog of 316 K giant candidates (Rebull+, 2015)J/A+A/587/A6 : Linelist of 14 Galactic post-AGB stars (De Smedt+, 2016)J/ApJS/226/1 : Carbon stars from LAMOST DR2 data (Ji+, 2016)J/AJ/156/300 : Velocity & light curve analysis of three PPNe (Hrivnak+,2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/159/21https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/159/21http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/159/21https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/159/21https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/159/21http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/159/21GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/159/21/table1 (List of the proto-planetary nebulae (PPNe) observed)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/159/21/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/159/21/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/159/21/table1?GETtext/xml+votable180.050000true68.237534.6033330.0055555555555555566/1229 4213 14323 22069 40566https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/159/21?format=asciiOpticalInfrareddefaultJ/AJ/159/21/table1List of the proto-planetary nebulae (PPNe) observedSpT3Spectral type 3src.spTypecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIRASIRAS identification of the PPN target (HHMMm+DDMM; B1950; Cat. II/125)meta.id;meta.maincharprimaryGSC2.3Identification from the Guide Star Catalog II, version 2.3.3 (I/305)meta.idchar2MASS2MASS identification (JHHMMSSss+DDMMSSss)meta.idcharRAJ20002MASS hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ20002MASS degree of declination (J2000)pos.eq.dec;meta.mainGLON[113/241] Galactic longitude (J2000)degpos.galactic.lonGLAT[-9/41] Galactic latitude (J2000)degpos.galactic.latfloatNpNumber of photometric measurements for this PPN (link to Table 7)meta.numberintnullableVmag[13/14] V band magnitude (1)magphot.mag;em.opt.VfloatB-V[1.2/2.4] B-V color index (1)phot.color;em.opt.B;em.opt.VfloatSpT1Spectral type 1src.spTypecharr_SpT1Reference flag on SpT1 (2)meta.ref;pos.framecharSpT2Spectral type 2src.spTypecharr_SpT2Reference flag on SpT2 (2)meta.ref;pos.framecharr_SpT3Reference flag on SpT3 (2)meta.ref;pos.framecharLCInteractive Plotmeta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/AJ/159/21/table7Differential standard magnitudesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIRASIRAS identification of PPN target (HHMMm+DDMM; B1950)meta.id;meta.maincharHJDV[54731/58240]? Heliocentric Julian Date, V band observation, HJD-2400000dtime.epochdoublenullableDelV[0.064/1.6]? Differential magnitude in V (offset included)magphot.mag;arith.difffloatnullableHJDRc[54731.9/567321]? Heliocentric Julian Date, Rc band observation, HJD-2400000dtime.epochdoublenullableDelRc[-0.68/0.81]? Differential magnitude in Rc (offset included)magphot.mag;arith.difffloatnullableTel[A-H] Telescope-detector-filter system code (1)meta.id;instr.telchar