J/A+A/707/A169 PN G054.2-03.4 light and velocity curves (Jones+, 2026)
Appraising the Necklace: A post-common-envelope carbon dwarf inside an
apparently carbon-poor planetary nebula.
Jones D., Corradi R.L.M., Garcia Perez G.A., Morisset C., Garcia-Rojas J.,
Sabin L., Balick B., Wise J., Mampaso A., Munday J., Rodriguez-Gil P.,
del Mar Rubio-Diez M., Santander-Garcia M., Sowicka P., Csukai A.,
Hillwig T.C., Henderson de la Fuente A., Terwel J.H.
<Astron. Astrophys. 707, A169 (2026)>
=2026A&A...707A.169J 2026A&A...707A.169J (SIMBAD/NED BibCode)
ADC_Keywords: Planetary nebulae ; Binaries, spectroscopic ; Photometry, ugriz ;
Radial velocities
Keywords: white dwarfs - stars: AGB and post-AGB - binaries: close -
stars: chemically peculiar - white dwarfs - ISM: abundances -
planetary nebulae: individual: PN G054.2-03.4
Abstract:
The Necklace nebula is a bipolar, post-common-envelope planetary
nebula, the central star of which has been shown to have a dwarf
carbon star companion. We aim to understand the origins of the
Necklace and its dwarf carbon central star. We study the carbon
abundance of the nebula through far ultraviolet spectroscopy obtained
with the Hubble Space Telescope. Furthermore, through simultaneous
modelling of multiband light and velocity curves, we attempt to
constrain the parameters of the central star system. Puzzlingly, we
find that the region of the inner nebula observed with the Hubble
Space Telescope is seemingly not carbon- rich, at odds with the dwarf
carbon star nature of the companion of the central star. The initial
mass of the nebular progenitor was likely very close to the limit to
become carbon-rich, perhaps experiencing a very late thermal pulse.
The dwarf carbon star companion is found to be significantly inflated
with respect to that expected for an isolated main sequence star of
the same mass. The properties of the central binary are consistent
with the progenitor having become carbon-rich and its companion having
accreted a significant amount of that carbon-enriched material.
However, it is unclear how this evolutionary hypothesis can be
reconciled with the inner nebula potentially being carbon poor.
Description:
Photometry of the central star of the Necklace nebula in g-, r- and
i-bands. Radial velocity measurements of the cool components of the
binary central star of the Necklace nebula.
Objects:
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RA (2000) DE Designation(s) (Period)
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19 43 59.5 -17 09 01 PN G054.2-03.4 = NAME Necklace (1.161393)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
gphot.dat 29 74 g-band light curve
iphot.dat 29 270 i-band light curve
rphot.dat 29 72 r-band light curve
ciirvs.dat 32 19 [CII] radial velocity curve
ciiibrvs.dat 33 55 [CIII] blue radial velocity curve
ciiirrvs.dat 33 39 [CII] red radial velocity curve
civrvs.dat 32 69 [CIV] radial velocity curve
niiirvs.dat 33 26 [NIII] radial velocity curve
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Byte-by-byte Description of file: gphot.dat iphot.dat rphot.dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d HJD Heliocentric Julian date
16- 21 F6.3 mag mag Apparent magnitude in Band
23- 27 F5.3 mag e_mag Uncertainty on apparent magnitude in Band
29 A1 --- Band [gri] Observed band
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Byte-by-byte Description of file: *rvs.dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d HJD Heliocentric Julian date
16- 22 F7.2 km/s RV Radial velocity
24- 28 F5.2 km/s e_RV Uncertainty on radial velocity measurement
30- 33 A4 --- Ion Ion
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Acknowledgements:
David Jones, djones(at)iac.es
(End) Patricia Vannier [CDS] 28-Jan-2026