J/A+A/669/A4 Orbital parallax of binary systems (Groenewegen, 2023)
Orbital parallax of binary systems compared to GAIA DR3 and the parallax
zero-point offset at bright magnitudes.
Groenewegen M.A.T
<Astron. Astrophys. 669, A4 (2023)>
=2023A&A...669A...4G 2023A&A...669A...4G (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Parallaxes, trigonometric ;
Binaries, orbits
Keywords: stars: distances - stars: fundamental parameters -
parallaxes - binaries: spectroscopic - binaries: visual
Abstract:
Multiple systems where the astrometric and spectroscopic orbit are
known offer the unique possibility to determine the distance to these
systems directly without any assumptions, and are therefore ideal
objects to compare Gaia data release 3 (GDR3) parallax data with,
especially since GDR3 presents the results of the non-single star
(NSS) analysis that potentially results in improved parallaxes. Such
an analysis is relevant in studying the parallax zero-point offset
(PZPO) that is crucial in improving upon the distance scale.
An sample of 192 orbital parallax determinations for 186 systems is
compiled from the literature. The stars are also potentially in wide
binary systems (WBS). A search was performed and 37 WBS (candidates)
were found.
Only for 21 objects does the NSS analysis provide information,
including eight from the astrometric binary pipeline, for which the
parallaxes do improve significantly on the ones in the main catalogue
with significant lower goodness-of-fit (GOF) parameters. It appears
that most of the objects in the sample are eliminated in the
pre-filtering stage of the NSS analysis.
The difference between the orbital parallax and the (best) Gaia
parallax was finally performed on 170 objects. A raw comparison is
meaningless however due to limitations in accuracy both in the orbital
and Gaia data. As many systems have been eliminated in the
pre-filtering stage of the astrometric NSS pipeline they remain in
GDR3 with values for the GOF parameter in the range from several tens
to several hundreds. Eliminating objects with large parallax errors or
unrealistically large differences between the orbital and Gaia
parallaxes, and a GOF <100 or <8 (the latter also with G<10.5mag
selected), samples of 68 and 20 stars remain. Parallax differences in
magnitude bins and for the sample are presented. Three recipes from
the literature that calculate the PZPO are tested. After applying
these corrections the remaining parallax differences are formally
consistent with zero within the error bar for all three recipes. In
all cases there remains an uncertainty in these averages of the order
10-15 microarcsec for these samples due to the small number
statistics.
The proof-of-concept of using orbital parallaxes is shown to work but
the full potential is not reached as only for eight systems an
improved parallax from the NSS analysis is available. In the final
selection 18 of 20 stars have an orbital parallax determined to better
than 5% and six have a parallax determination better than from Gaia.
In the full sample 148 objects reach this precision and therefore the
full potential of using orbital parallaxes may hopefully be reached
with GDR4.
Description:
The tabular material list the orbital elements compiled from the
literature basic parameters for the sample of stars (Table 1) and the
derived orbital parallax together with data from Hipparcos and Gaia
(Table 2).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 165 192 Sample of stars: orbital elements
table2.dat 135 192 Sample of stars: parallax data
refs.dat 122 143 References
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
I/357 : Gaia DR3 Part 3. Non-single stars (Gaia Collaboration, 2022)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Name Identifier used in this paper, following
the WDS convention (HHMMm+DDMM)
12- 17 I6 --- HD ? HD number
19- 29 F11.5 --- Per Orbital (Pulsation) period
31- 39 F9.5 --- e_Per Orbital period error
40 A1 --- nePer [*] * indicates that the error bar was assumed
42 A1 --- x_Per Period unit
(y = years, d = days, h = hours, m = minutes)
44- 52 F9.6 arcsec amaj Semi-major axis
54- 61 F8.6 arcsec e_amaj Semi-major axis error
62 A1 --- neamaj [*] * indicates that the error bar was assumed
65- 71 F7.3 deg Incl Inclination
73- 78 F6.3 deg e_Incl Inclination error
79 A1 --- neIncl [*] * indicates that the error bar was assumed
81- 87 F7.5 --- e Eccentricity
89- 95 F7.5 --- e_e Eccentricity error
96 A1 --- nee [*] * indicates that the error bar was assumed
98-104 F7.3 km/s K1 Semi-amplitude of component 1
105-110 F6.3 km/s e_K1 Semi-amplitude of component 1 error
111 A1 --- neK1 [*] * indicates that the error bar was assumed
114-120 F7.3 km/s K2 Semi-amplitude of component 2
122-127 F6.3 km/s e_K2 Semi-amplitude of component 2 error
128 A1 --- neK2 [*] * indicates that the error bar was assumed
130-165 A36 --- Refs References
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Name Identifier
12- 18 F7.3 mas oplx Orbital parallax
20- 25 F6.3 mas e_oplx Orbital parallax error
27- 32 I6 --- HIP ? Hipparcos identifier
34- 40 F7.2 mas Hplx ? Hipparcos parallax
42- 46 F5.2 mas e_Hplx ? Hipparcos parallax error
48- 52 F5.2 --- HGoF ? Hipparcos goodness-of-fit parameter
54- 58 F5.2 mag Hpmag ? Hipparcos Hp magnitude
61- 79 I19 --- GaiaDR3 ? GAIA source identifier
81- 87 F7.3 mas plx ? GAIA parallax
89- 93 F5.3 mas e_plx ? GAIA parallax error
95-101 F7.2 --- GoF ? GAIA Goodness-of-fit
103-108 F6.2 --- RUWE ? GAIA RUWE
110-114 F5.2 mag Gmag ? GAIA G-band magnitude
116 I1 --- NSS [0/3]? GAIA non-single star flag
118-119 I2 --- ipdfmp [0/99]? GAIA Percent of successful-IPD windows
with more than one peak
(ipd_frac_multi_peak)
121-124 F4.2 --- ipdha [0/0.65]? GAIA Amplitude of the IPD GoF versus
position angle of scan
(ipd_gof_harmonic_amplitude)
126-127 I2 --- Nv [3/29]? GAIA Number of visibility periods used
in Astrometric solution
(visibility_periods_used)
129-135 F7.3 --- signiC ? Significance of the modified Bp-Rp excess (1)
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Note (1): significance of the modified Bp-Rp excess (C*), calculated
according to Riello et al. (2021A&A...649A...3R 2021A&A...649A...3R, Cat. J/+A/649/A3).
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 20 A20 --- Ref Reference code
22- 40 A19 --- BibCode BibCode
42- 64 A23 --- Aut Author's name
66-122 A57 --- Com Comments
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Acknowledgements:
Martin Groenewegen, martin.groenewegen(at)oma.be
(End) Patricia Vannier [CDS] 11-Nov-2022