J/AJ/169/211 Binaries orbital parameters comparison with Gaia DR3 (Ding+, 2025)
Analysis of the Gaia Data Release 3 parallax bias at bright magnitudes.
Ding Ye, Liao S., Wen S., Qi Z.
<Astron. J., 169, 211 (2025)>
=2025AJ....169..211D 2025AJ....169..211D
ADC_Keywords: Binaries, orbits; Stars, double and multiple; Positional data;
Parallaxes, trigonometric; Optical
Keywords: Astrometry ; Gaia ; Parallax
Abstract:
The combination of visual and spectroscopic orbits in binary systems
enables precise distance measurements without additional assumptions,
making them ideal for examining the parallax zero-point offset (PZPO)
at bright magnitudes (G<13) in Gaia. We compiled 249 orbital
parallaxes from 246 binary systems and used Markov chain Monte Carlo
simulations to exclude binaries where orbital motion significantly
impacts parallaxes. After removing systems with substantial parallax
errors, large discrepancies between orbital and Gaia parallaxes, and
selecting systems with orbital periods under 100 days, a final sample
of 44 binaries was retained.The weighted mean PZPO for this sample is
-38.9±10.3µas, compared to -58.0±10.1µas for the remaining
systems, suggesting that orbital motion significantly affects parallax
measurements. These formal uncertainties of the PZPO appear to be
underestimated by a factor of approximately 2.0. For bright stars with
independent trigonometric parallaxes from Very Long Baseline
Interferometry and Hubble Space Telescope, the weighted mean PZPOs are
-14.8±10.6 and -31.9±14.1µas, respectively. Stars with G≤8
exhibit a more pronounced parallax bias, with some targets showing
unusually large deviations, likely due to systematic calibration
errors in Gaia for bright stars. The orbital parallaxes dataset
compiled in this work serves as a vital resource for validating
parallaxes in future Gaia data releases.
Description:
We compile a list of 249 orbital parallaxes for 246 systems from
various literature, with Gaia DR3 (I/355) identifiers provided by
SIMBAD. For three binaries, several components have been resolved (WDS
03272+0944, 20396+0458, and 22388+4419), and therefore the table has
249 entries. Among them, only one system (ROXs 47A) has no WDS, HD, and
HIP number. Compared to Groenewegen+2023 (J/A+A/669/A4), our sample
contains 67 new binaries and 157 overlapped binaries but with orbital
parallaxes obtained from other studies. Among 249 sources, only 35
have a nonzero non-single-star (NSS) flag in Gaia DR3. In other words,
86% of the known binaries have not been identified as binary in Gaia
DR3, likely due to Gaia DR3 focusing on the most significant systems.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 442 249 Complete binary sample
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See also:
B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2020)
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
I/357 : Gaia DR3 Part 3. Non-single stars (Gaia Collaboration, 2022)
III/135A : Henry Draper Cat. and Extension (Cannon+ 1918-1924; ADC 1989)
J/A+A/558/A53 : Milky Way global surv. of star clust. II. (Kharchenko+, 2013)
J/A+A/564/A79 : Proper motions of open clusters from UCAC4 (Dias+, 2014)
J/AJ/148/48 : CHARA obs. of omega And, HD 178911, xi Cep (Farrington+, 2014)
J/AJ/147/123 : Speckle interferometry with SOAR in 2012-2013 (Tokovinin+, 2014)
J/AJ/152/138 : Orbits based on speckle interferometry at SOAR (Tokovinin, 2016)
J/AJ/160/58 : Orbits of spectro. binar. with CHARA Array. III. (Lester+, 2020)
J/MNRAS/492/2709 : Double-lined spectroscopic binaries cat. (Piccotti+, 2020)
J/A+A/649/A6 : Gaia Catalogue of Nearby Stars - GCNS (Gaia collaboration, 2021)
J/A+A/654/A20 : Plx zero-point offset from Gaia EDR3 data (Groenewegen, 2021)
J/A+A/672/A119 : 10 double-lined spectroscopic binaries data (Gallenne+, 2023)
J/A+A/669/A4 : Orbital parallax of binary systems (Groenewegen, 2023)
J/A+A/674/A10 : Gaia DR3 systems with companions (Holl+, 2023)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- WDS WDS (B/wds) number
12- 17 I6 --- HD [3196/286820]? HD (III/135A) number
19- 24 I6 --- HIP [171/118077]? Hipparcos (I/239) ID
26- 44 I19 --- GaiaDR3 Gaia DR3 (I/355) source ID
46- 60 F15.8 d Per [1.1/167939] Orbital period
62- 76 F15.9 d e_Per [8e-8/35064]? Uncertainty in Per
78- 94 F17.8 d T [-2341858/2452600]? Time of passage through
periastron; Modified Julian Date
96- 108 F13.8 d e_T [2e-4/1315]? Uncertainty in T
110- 118 F9.4 mas a [0.4/6732] Semi-major axis
120- 126 F7.4 mas e_a [1e-3/50]? Uncertainty in a
128- 135 F8.6 --- e [0/0.98]? Eccentricity
137- 144 F8.6 --- e_e [0/0.12]? Uncertainty in e
146- 157 F12.8 deg i [7.1/163]? Inclination
159- 169 F11.8 deg e_i [4e-3/33]? Uncertainty in i
171- 178 F8.4 deg omega [-90.8/361.3]? Argument of periastron
180- 191 F12.8 deg e_omega [0.01/128]? Uncertainty in omega
193- 204 F12.8 deg Omega [-35.6/359.61]? Longitude of ascending node
206- 216 F11.8 deg e_Omega [0.01/28]? Uncertainty in Omega
218- 229 F12.8 km/s K1 [1.46/544]? Semi-amplitude of component 1
231- 242 F12.8 km/s e_K1 [1e-3/200]? Uncertainty in K1
244- 255 F12.8 km/s K2 [-75.3/117.5]? Semi-amplitude of component 2
257- 267 F11.8 km/s e_K2 [7e-3/48]? Uncertainty in K2
269- 277 F9.5 mas oplx [0.4/294] Orbital parallax
279- 287 F9.6 mas e_oplx [6e-3/29.6] Uncertainty in oplx
289- 300 F12.8 mas oplxG23 [0.5/250.7]? Orbital parallax from
Groenewegen+2023 (J/A+A/669/A4)
302- 312 F11.8 mas e_oplxG23 [8e-3/29.6]? Uncertainty in oplxG23
314- 325 F12.8 mas plxGaia [0.4/195.6]? Gaia DR3 (I/355) parallax
327- 336 F10.8 mas e_plxGaia [0.01/1.1]? Uncertainty in plxGaia
338- 339 A2 --- fG23 Indicates whether binary is included in
Groenewegen+2023 (J/A+A/669/A4) (1)
341- 344 A4 --- good Classification of solution (2)
346- 382 A37 --- Ref References
384- 442 A59 --- BibCode BibCodes for references
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Note (1): G23 refers to Groenewegen+2023 (J/A+A/669/A4). Flag as follows:
A = the new binary is not included in G23 (67 occurrences)
B1 = G23 gives a different orbital parallax than the one used here
adopted from reference (157 occurrences)
B2 = the orbital parallax in G23 was adopted (25 occurrences)
Note (2): We define a solution as "good" if each binary's solutions satisfy the
condition |plxGDR3-plxSimu|/plxGDR3<0.2 with a confidence level
of 95% in MCMC, where plxGDR3 and plxSimu indicate the Gaia DR3
and simulated parallax, respectively. Among 132 filtered binaries,
93 are identified as "good" solutions (See Section 3.1).
Classification as follows:
true = the filtered binary's solutions satisfy the condition described
above (93 occurrences)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Robin Leichtnam [CDS] 13-Jan-2026