J/ApJ/901/9 Variability in protoplanetary nebulae. VII. 5 LCs (Hrivnak+, 2020)
Variability in protoplanetary nebulae:
VII. Light-curve studies of five medium-bright, oxygen-rich, or mixed-chemistry
post-AGB/post-RGB objects.
Hrivnak B.J., Henson G., Hillwig T.C., Lu W., Nault K.A., Volk K.
<Astrophys. J., 901, 9 (2020)>
=2020ApJ...901....9H 2020ApJ...901....9H
ADC_Keywords: Planetary nebulae; Photometry, VRI; Spectral types
Keywords: Protoplanetary nebulae ; Post-asymptotic giant branch stars ;
Stellar pulsations ; Pulsating variable stars ;
Multi-periodic pulsation ; Circumstellar dust ; Circumstellar matter
Abstract:
We have monitored over a 10-year interval the light variations of five
evolved stars with very large mid-infrared excesses. All five objects
appear to have oxygen-rich or mixed oxygen-rich and carbon-rich
chemistries. They all vary in light: four over a small range of
∼0.2mag and the fifth over a larger range of ∼0.7mag. Spectral types
range from G2 to B0. Periodic pulsations are found for the first time
in the three cooler ones, IRAS18075-0924 (123d), 19207+2023 (96d), and
20136+1309 (142d). No significant periodicity is found in the hotter
ones, but they appear to vary on a shorter timescale of a few days or
less. Two also show some evidence of longer-term periodic variations
(∼4yr). Three appear to be protoplanetary nebulae (PPNe), in the
post-asymptotic giant branch (post-AGB) phase of stellar evolution.
Their light variations are in general agreement with the relationships
among temperature, pulsation period, and pulsation amplitude found in
previously studied PPNe. The other two, however, appear to have too
low a luminosity (1000-1500L☉), based on Gaia distances, to be
in the post-AGB phase. Instead, they appear to be Milky Way analogs of
the recently identified class of dusty post-red giant branch
(post-RGB) stars found in the Magellanic Clouds, which likely had
their evolution interrupted by interaction with a binary companion. If
this is the case, then these would be among the first dusty post-RGB
objects identified in the the Milky Way.
Description:
Most of the observations were carried out at the Valparaiso University
Observatory (VUO) with the 0.4m telescope and SBIG 6303 CCD camera.
Observations began in 2008 and were carried out through 2017 or 2018,
depending upon the object.
These were complemented by observations made with two telescopes
operated by the Southeastern Association for Research in Astronomy
(SARA). They are the 0.9m at Kitt Peak National Observatory (SARA-KP)
and the 0.6m Lowell telescope at Cerro-Tololo Interamerican
Observatory (SARA-CT). The SARA observations began in 2009 or 2010 and
continued through 2016 or 2018, depending upon the object.
Standard Johnson V and Cousins RC filters were used with each of the
telescope-detector systems.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 102 5 List of protoplanetary nebula (PPN) targets observed
tablea2.dat 52 1087 Differential standard magnitudes
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See also:
II/118 : UBVRI standards around Celestial Equator (Landolt 1983)
II/125 : IRAS catalogue of Point Sources, Version 2.0 (IPAC 1986)
II/183 : UBVRI Photometric Standards (Landolt 1992)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/305 : The Guide Star Catalog, Version 2.3.2 (GSC2.3) (STScI, 2006)
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
J/ApJS/92/125 : Post-AGB evolution (Vassiliadis+, 1994)
J/A+A/299/755 : Stellar evolution. II. Post-AGB (Bloecker+, 1995)
J/A+A/458/173 : Optical spectroscopy of 253 IRAS sources (Suarez+, 2006)
J/PAZh/36/281 : Variability of 3 protoplanetary nebulae (Arkhipova+, 2010)
J/ApJ/709/1042 : Variability in C-rich proto-PNe. (Hrivnak+, 2010)
J/ApJ/766/116 : Variability in proto-PNe. II. (Hrivnak+, 2013)
J/MNRAS/439/2211 : Post-AGB/RGB and YSOs in SMC (Kamath+, 2014)
J/ApJ/794/81 : Maser and IR studies of oxygen-rich AGB stars (Yung+, 2014)
J/AJ/149/184 : Long-term photometry for 4 O-rich PPne (Hrivnak+, 2015)
J/MNRAS/454/1468 : LMC post-AGB, post-RGB star and YSOs (Kamath+, 2015)
J/MNRAS/447/1673 : Galactic post-AGB stars distances (Vickers+, 2015)
J/A+A/588/A25 : Post-AGB & CSPNe models (Miller Bertolami, 2016)
J/ApJ/826/44 : Spitzer/IRS obs. of Magellanic carbon stars (Sloan+, 2016)
J/AJ/156/300 : Velocity and LC analysis of three PPNe (Hrivnak+, 2018)
J/AJ/159/21 : V and Rc light curves of medium-bright PPNe (Hrivnak+, 2020)
J/A+A/649/A164 : Protoplanetary nebulae & young PN CO sp. (Lorenzo+, 2021)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- IRAS IRAS name (HHMMm+DDMM)
12- 21 A10 --- GSC GSC2.3.2 identifier
23- 39 A17 --- 2MASS 2MASS name (JHHMMSSss+DDMMSSs)
41- 42 I2 h RAh 2MASS hour of right ascension (J2000)
44- 45 I2 min RAm 2MASS minute of right ascension (J2000)
47- 51 F5.2 s RAs 2MASS second of right ascension (J2000)
53 A1 --- DE- 2MASS sign of declination (J2000)
54- 55 I2 deg DEd 2MASS degree of declination (J2000)
57- 58 I2 arcmin DEm 2MASS arcminute of declination (J2000)
60- 63 F4.1 arcsec DEs 2MASS arcsecond of declination (J2000)
65- 69 F5.1 deg GLON [19.8/54.8] Galactic longitude
71- 75 F5.1 deg GLAT [-12/4.7] Galactic latitude
77- 80 F4.1 mag Vmag [13.4/15.2] Johnson V magnitude (1)
82- 84 F3.1 mag B-V [1/2.5] B-V color index (1)
85 A1 --- u_B-V [:] : uncertainty flag on B-V
87- 93 A7 --- SpT Spectral type
95 A1 --- r_SpT Flag on SpT (2)
97- 100 A4 --- SpT2 Second spectral type for IRAS 20136+1309
102 A1 --- r_SpT2 Flag on second spectral type (2)
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Note (1): These values are all variable as discussed in this paper.
Note (2): Flag as follows:
d = Spectral types by Suarez+ (2006, J/A+A/458/173). However, we regard
their classification of IRAS19306+1407 as G5 I to be in error; see
discussion by Sanchez Contreras+ (2008ApJS..179..166S 2008ApJS..179..166S).
e = Based on our unpublished spectra; note that we have not included the
uncertain spectral types listed with colons by
Kelly & Hrivnak (2005ApJ...629.1040K 2005ApJ...629.1040K).
f = Spectral types by Sanchez Contreras+ (2008ApJS..179..166S 2008ApJS..179..166S).
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Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [IRAS]
5- 14 A10 --- IRAS IRAS name of PPN target
16- 25 F10.4 d HJDV [49558.7/58311.8]? Heliocentric Julian Date
of V band; HJDV-2400000
27- 32 F6.3 mag DelV [-0.08/1.88]? Differential V band magnitude (1)
34- 43 F10.4 d HJDRc [49873.8/58311.8]? Heliocentric Julian Date
of Rc band; HJDRc-2400000
45- 50 F6.3 mag DelRc [-0.5/0.97]? Differential Rc band magnitude (1)
52 A1 --- Code Telescope-Detector-filter system code (2)
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Note (1): Offset included. Typical uncertainty in the studies is ±0.015mag.
Note (2): This identifies the source of the photometry, as listed in Table 7,
and the associated added offset, if any, to bring that observation
to the VUO system.
Code as follows:
A = the Valparaiso University Observatory (VUO) with the 0.4m telescope and
SBIG 6303 CCD camera (offset=0.00mag);
B = the 0.9m at Kitt Peak National Observatory (SARA-KP) U42;
C = SARA-KP U42 (alternate filter set);
D = SARA-KP FLI;
E = SARA-KP ARC;
F = the 0.6m Lowell telescope at Cerro-Tololo Interamerican Observatory
(SARA-CT) E6;
G = SARA-CT ARC;
H = SARA-CT FLI;
I = VUO PHOT.
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History:
From electronic version of the journal
References:
Hrivnak et al. Paper I. 2010ApJ...709.1042H 2010ApJ...709.1042H Cat. J/ApJ/709/1042
Hrivnak et al. Paper II. 2013ApJ...766..116H 2013ApJ...766..116H Cat. J/ApJ/766/116
Hrivnak et al. Paper III. 2015ApJ...805...78H 2015ApJ...805...78H
Hrivnak et al. Paper IV. 2015AJ....149..184H 2015AJ....149..184H Cat. J/AJ/149/184
Hrivnak et al. Paper V. 2018AJ....156..300H 2018AJ....156..300H Cat. J/AJ/156/300
Hrivnak et al. Paper VI. 2020AJ....159...21H 2020AJ....159...21H Cat. J/AJ/159/21
Hrivnak et al. Paper VII. 2020ApJ...901....9H 2020ApJ...901....9H This catalog
Hrivnak et al. Paper VIII. 2021AJ....162..248H 2021AJ....162..248H
Hrivnak et al. Paper IX. 2022ApJ...939...32H 2022ApJ...939...32H Cat. J/ApJ/939/32
Hrivnak et al. Paper X. 2024AJ....167...30H 2024AJ....167...30H Cat. J/AJ/167/30
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 05-Jan-2022