J/A+A/623/A72 Binarity of Hipparcos stars from Gaia pm anomaly (Kervella+, 2019)
Stellar and substellar companions of nearby stars from Gaia DR2.
Binarity from proper motion anomaly.
Kervella P., Arenou F., Mignard F., Thevenin F.
<Astron. Astrophys. 623, A72 (2019)>
=2019A&A...623A..72K 2019A&A...623A..72K (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, nearby ; Stars, double and multiple ;
Proper motions
Keywords: astrometry - proper motions - binaries: general - planetary systems
Abstract:
The census of stellar and substellar companions of nearby stars is
largely incomplete, in particular towards the low mass brown dwarf and
long-period exoplanets. It is however of fundamental importance to
understand the stellar and planetary formation and evolution
mechanisms. Nearby stars are particularly favorable targets for high
precision astrometry.
We aim at characterizing the presence of physical companions of
stellar and substellar mass in orbit around nearby stars.
Orbiting secondary bodies influence the proper motion of their parent
star through their gravitational reflex motion. Using the Hipparcos
and Gaia DR2 catalogs, we determine the long-term proper motion of the
stars common to these two catalogs. We then search for a proper motion
anomaly (PMa) between the long-term proper motion vector and the Gaia
DR2 (or Hipparcos) measurements, indicative of the presence of a
perturbing secondary object. We focus our analysis on the 6741 nearby
stars located within 50pc, and we also present a catalog of the PMa
for >99 percent of the stars of the full Hipparcos catalog.
A fraction of 30 percent of the studied stars presents a PMa at a
level of more than 3 sigma. The PMa allows us to detect orbiting
companions, or set stringent limits to their presence. We present a
few illustrations of the PMa analysis to interesting targets. We set
upper limits of 0.1-0.3MJ to potential planets orbiting Proxima
between 1 and 10au (Porb=3 to 100 years). We confirm that Proxima
is gravitationally bound to alpha Cen. We recover the masses of the
known companions of epsilon Eri, epsilon Ind, Ross 614 and beta Pic.
We also detect the signature of a possible planet of a few jovian
masses orbiting tau Ceti.
Based on only 22 months of Gaia data, the DR2 has limitations, but its
combination with the Hipparcos catalog and the very high accuracy of
the derived PMa already enables to set valuable constraints on the
binarity of nearby objects. The detection of tangential velocity
anomalies at a median accuracy of sigma(ΔvT)=1.0m/s per parsec
of distance is already possible with the Gaia DR2. This type of
analysis opens the possibility to identify long period orbital
companions otherwise inaccessible. The complementarity of Gaia (for
long orbital periods), radial velocity and transit techniques (for
short periods) already appears as remarkably powerful.
Description:
Proper motion anomaly (PMa) of nearby stars from the Hip2 (van Leeuwen
2007, Cat. I/311) and Gaia DR2 (I/345) catalogs. The proper motion
vectors at the Hipparcos and Gaia DR2 epochs are compared to the
long-term proper motion vector derived from the Hip2 and Gaia DR2
positions.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
hipgpma.dat 449 117206 Proper motion anomaly of Hipparcos stars
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2014)
Byte-by-byte Description of file: hipgpma.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HIP Hipparcos catalog number
8- 26 I19 --- GDR2 Gaia DR2 source number
28- 48 A21 --- Name Common name
50 I1 --- DMS [0/1] Set to 1 for stars present in the
Hipparcos Double and Multiple catalog
(I/239/h_dm_com)
52 A1 --- DT [FIL] Type of DMS catalog solution (1)
54 A1 --- DQ [ABCD] Quality of DMS catalog solution (2)
56 I1 --- W [0/1] Set to 1 if in the WDS catalog (B/wds)
58- 63 F6.3 mag Vmag ?=0 V band magnitude
65- 72 F8.5 mag Gmag Gaia G band magnitude
74- 79 F6.4 mag e_Gmag Standard error on Gaia G band magnitude
81- 86 F6.3 mag Kmag 2MASS K band magnitude
88- 92 F5.3 mag e_Kmag Standard error on 2MASS K band magnitude
94- 98 F5.3 mag E(B-V) E(B-V) color excess
100 A1 --- r_E(B-V) [S] Reference for E(B-V) color excess (3)
102-123 A22 --- SpType Spectral type from CDS Simbad
125-131 F7.2 mas PlxHip Hipparcos 2 (van Leeuwen 2007) parallax
133-138 F6.2 mas e_PlxHip Standard error on Hip2 parallax
140-146 F7.3 mas PlxG2 Gaia DR2 parallax (ZP corrected)
148-152 F5.3 mas e_PlxG2 Standard error on Gaia DR2 parallax
154-159 F6.3 mas epsi Gaia DR2 excess noise (epsilon)
161-167 F7.3 --- RUWE Gaia DR2 renormalizer unit weight error
169-176 F8.3 km/s RV Radial velocity
178-184 F7.3 km/s e_RV ?=999 Standard error on radial velocity
186-188 A3 --- r_RV Reference of radial velocity (4)
190-198 F9.3 mas/yr pmHGRAH Hip-Gaia proper motion in RA direction
(pmRA*cosDE) at epoch 1991.25
200-204 F5.3 mas/yr e_pmHGRAH Standard error on Hip-Gaia PM in RA
direction at epoch 1991.25
206-214 F9.3 mas/yr pmHGDEH Hip-Gaia proper motion in declination
direction at epoch 1991.25
216-220 F5.3 mas/yr e_pmHGDEH Standard error on Hip-Gaia PM in Dec
direction at epoch 1991.25
222-229 F8.3 mas/yr PMaRAH Hip-HG proper motion anomaly in RA
direction at epoch 1991.25
231-237 F7.3 mas/yr e_PMaRAH Standard error on Hip-HG PMa in RA
direction at epoch 1991.25
239-246 F8.3 mas/yr PMaDEH Hip-HG proper motion anomaly Hip-HG in Dec
direction at epoch 1991.25
248-254 F7.3 mas/yr e_PMaDEH Standard error on Hip-HG PMa in Dec
direction at epoch 1991.25
256-261 F6.2 --- PMaH Signal-to-noise ratio of Hip-HG PMa
263 I1 --- BinH [0/1] Hip PMa binary flag (=1 for PMaH>3)
265-273 F9.3 mas/yr pmHGRAG Hip-Gaia proper motion in RA direction
(pmRA*cosDE) at epoch 2015.5
275-279 F5.3 mas/yr e_pmHGRAG Standard error on Hip-Gaia PM in RA
direction at epoch 2015.5
281-289 F9.3 mas/yr pmHGDEG Hip-Gaia proper motion in declination
direction at epoch 2015.5
291-295 F5.3 mas/yr e_pmHGDEG Standard error on Hip-Gaia PM in Dec
direction at epoch 2015.5
297-304 F8.3 mas/yr PMaRAG GDR2-HG proper motion anomaly in RA
direction at epoch 2015.5
306-310 F5.3 mas/yr e_PMaRAG Standard error on GDR2-HG PMa in RA
direction at epoch 2015.5
312-319 F8.3 mas/yr PMaDEG GDR2-HG proper motion anomaly Hip-HG in Dec
direction at epoch 2015.5
321-325 F5.3 mas/yr e_PMaDEG Standard error on GDR2-HG PMa in Dec
direction at epoch 2015.5
327-332 F6.2 --- PMaG2 Signal-to-noise ratio of GDR2-HG PMa
334 I1 --- BinG2 [0/1] GDR2 PMa binary flag (=1 for PMaG2>3)
336-345 F10.2 m/s dVt Tangential velocity anomaly
347-356 F10.2 m/s e_dVt Standard error on tangential velocity dVt
358-363 F6.2 deg dVtPA Position angle of velocity anomaly vector
365-369 F5.2 deg e_dVtPA Standard error on PA of dVt vector
371-376 F6.3 au OrbG2 Radius of orbit with period corresponding to
Gaia DR2 observing window duration
378-384 F7.3 Msun M1 Mass of primary star
386-391 F6.3 Msun e_M1 Standard error on mass of primary
393-395 A3 --- r_M1 Reference for mass of primary (5)
397-405 F9.3 Rsun R1 Radius of primary star
407-413 F7.3 Rsun e_R1 Standard error on radius of primary star
415-418 A4 --- r_R1 Reference for radius of primary (6)
420-429 F10.2 Mjup M2n Mass of secondary normalized to 1 au
431-439 F9.2 Mjup E_M2n Positive error bar on M2n
441-449 F9.2 Mjup e_M2n Negative error bar on M2n
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Note (1): Type of DMS catalog solutions as follows:
F = fixed double or multiple system
I = individual parallaxes and linear motion
L = linear double or multiple system
Note (2): Quality of DMS catalog solution as follows:
A = good
B = fair
C = poor
D = uncertain
Note (3): Reference for E(B-V) color excess as follows:
S = Stilism
B = Bayestar17
Note (4): Reference of radial velocity as follows:
A93 = Aannestad et al. (1993AJ....105.1033A 1993AJ....105.1033A)
A12 = Anderson et al. (2012AstL...38..331A 2012AstL...38..331A, Cat. V/137)
DR2 = Gaia DR2 (2018, Cat. I/345)
H07 = Holmberg et al. (2007A&A...475..519H 2007A&A...475..519H, Cat. V/117)
K17 = Kervella et al. (2017A&A...598L...7K 2017A&A...598L...7K)
N02 = Nidever et al. (2002, Cat. J/ApJS/141/403)
S18 = Soubiran et al. (2018A&A...616A...7S 2018A&A...616A...7S, Cat. I/345)
Note (5): Reference for mass of primary as follows:
F97 = Finley et al. (1997ApJ...488..375F 1997ApJ...488..375F)
H16 = Holberg et al. (2016, Cat. J/MNRAS/462/2295)
K04 = Kervella et al. (2004A&A...426..297K 2004A&A...426..297K)
K04G = Kervella et al. (2004A&A...426..297K 2004A&A...426..297K) (Gmag)
M15 = Mann et al. (2015, Cat. J/ApJ/802/77)
Pow = Power law
Note (6): Reference for radius of primary as follows:
H16 = Holberg et al. (2016, Cat. J/MNRAS/462/2295)
K04 = Kervella et al. (2004A&A...426..297K 2004A&A...426..297K)
K04G = Kervella et al. (2004A&A...426..297K 2004A&A...426..297K) (Gmag)
M15 = Mann et al. (2015, Cat. J/ApJ/802/77)
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Acknowledgements:
Pierre Kervella, pierre.kervella(at)obspm.fr
(End) Patricia Vannier [CDS] 28-Jan-2019