Candidate Kinematic Groups Among Stars with Planets

Home , Castor (star), Gliese 393, HD 1237, HD 92788

Submitted to ApJ May 18, 2001

Jean-Marc Deltorn1

Space Telescope Science Institute, Baltimore, MD 21218

and

Paul Kalas2,3

University of California, Berkeley, CA 94720

[email protected]

ABSTRACT

We use the Hipparcos catalog to search for stars that share the space velocities of 57 stars with planets. We ﬁnd 27 stars with planets have at least one “kinematic companion” in a U, V, W box with size 4, 2 and 6 km s−1, respectively. Thirteen stars with planets have space motions that match those of possible kinematic groups. A Kolmogorov-Smirnov test on the metallicity distribution of F, G, and K stars shows that the stars with planets and their kinematic companions are likely members of the same, higher metallicity population, and separate from a control sample of stars without planets and their companions. Six stars with planets share similar space velocities with the Hyades moving group. Four stars share the space motions of the Pleiades moving group. HD 19994, HD 160691, and HD 186427 match the space velocities of the IC 2391, Centaurus-Crux, and Wolf 630 moving groups, respectively. HD 27442 and HD 92788 have no companions in velocity space except for each other, kinematically appearing as sister stars with planets. Future observational and theoretical tests are required to understand the nature of these candidate kinematic groups.

Subject headings: planetary systems—Hipparcos—stellar kinematic groups

1Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 2Astronomy Dept., 601 Campbell Hall, University of California, Berkeley, CA 94720 3NSF Center for Adaptive Optics, University of California –2–

1. Introduction

One of the most significant findings related to planet formation is that 5% of nearby F, G, and K dwarfs are orbited by extrasolar giant planets (Marcy et al. 2000). Given the 58 known stars with planets (SWPs), we can begin to test how and why the properties of these systems are unique relative to the entire population of nearby stars. Particularly helpful information would be to identify other stars that formed in the same physical environment as each SWP. A study of such a group could reveal the circumstances and physical conditions that are linked to the formation of giant planets. One distinguishing characteristic of stars with planets is that they have significantly higher metallicities than comparable stars of the same spectral type (Butler et al. 2000; Santos et al. 2001). This correlation of extrasolar planets with high metallicity stars could be due to the accretion of rocky material or planets onto the stellar photosphere after the protoplanetary phase (Laughlin 2000; Sandquist et al. 1998). On the other hand, the high metallicities may originate from the time of star formation due to conditions unique to the parental cloud (Santos et al. 2001; Pinsonneault et al. 2001). Objects that are members of the same star forming environment will share similar locations and kinematics when they are young. Their velocity dispersion will initially trace the velocity dispersion of the parental cloud. As the parental cloud disperses in 107-108 years, the velocity dispersion of some members may increase significantly due to interactions with other stars, spiral arms, and massive molecular clouds (Asiain et al. 1999b). Without any significant disruption, the random dispersion in V4 will stretch the group into a tube during its Galactic orbit (Skuljan et al. 1997). The U and W velocities will also evolve from their initial values and eventually oscillate out of phase. However, even though the spatial cohesiveness disappears on timescales of one galactic orbit, some fraction of the initial group will share a similar V velocity component on timescales of several galactic orbits (Skuljan et al. 1999). Numerous stellar kinematic groups (Table 1) have been identified based on the above arguments. Most kinematic group identified so far are relatively young, <1 Gyr associations of stars in the process of being scattered. Older kinematic associations could, in principle, retain enough cohesiveness in velocity space to be classified as stellar kinematic associations even after 1 Gyr (Wielen 1971; Terlevich 1987), as in the case of the HR 1614 kinematic group (Feltzing & Holmberg 2000). The density in (U,V,W) space of such groups shall

4Unless otherwise noted, space velocities are given relative to the Sun with positive U directed toward the galactic center, positive V in the direction of galactic rotation, and positive W in the direction of the north galactic pole. –3–

nonetheless decrease with time, impairing the probability of identifying a large fraction of the same initial kinematic association. The present sample of SWPs are chromospherically quiet and generally have estimated ages between 1 and 10 Gyr. The likelihood that sister stars from the time of star formation still share their kinematics is low. Nevertheless, we ﬁnd that two SWPs, HD 75732 (55 Cnc) and HD 134987, are already listed as possible members of the Hyades Group (Eggen 1985, 1996). These pre-Hipparcos studies relied on proper motion and parallax information only. In the post-Hipparcos era the study of stellar kinematic groups is pushing forward with more precise position, proper motion, and parallax information that when combined with radial velocity data gives improved knowledge of the 3-dimensional spatial kinematics (Chereul et al. 1999; Skuljan et al. 1999; Asiain et al. 1999a). The primary goal of this paper is to identify stars in the Hipparcos catalog that share the U, V, W space motions of SWPs. We will call stars that have matching U, V, W motions “kinematic companions” without implying that this test establishes a real physical connection in a group’s dynamical or chemical history. We present our list of kinematic companions purely as candidate moving groups that should be investigated more thoroughly. In addition to the kinematic test, we will study the metallicity correlation between the SWPs and their companions, and a control group and their companions.

2. Method

We cross-correlate the 118,218 stars in the Hipparcos catalog with the 36,145 stars in the Barbier-Brossat & Figon (2000) catalog of stellar radial velocities (hereafter BBF). For the 21,497 stars shared between the two catalogs, we derive the U, V, W velocity components and their standard deviations (Johnson & Soderblom 1987) using the Hipparcos data for positions, proper motions, and parallaxes.5 For the SWPs we use the mean radial velocities and standard deviations that have been determined by the planet search programs. The SWP BD -10 3166 was not detected by Hipparcos and is excluded from our study, leaving a total SWP sample of 57 stars. We deﬁne a box with dimensions (∆U, ∆V, ∆W) = (4, 2, 6) km s−1 centered on the average U, V, W values for each SWP. The space velocities of a given co-eval group will evolve out of this box, and in fact the U, V, W distribution resembles a tilted spheroid rather than

5Relative to the Local Standard of Rest, the Sun has U = 10.0 km s−1,V=5.25kms−1, and W = 7.17 km s−1 (Dehnen & Binney 1998). –4–

a box (Skuljan et al. 1997). By making the box small we are selecting only a core group of co-moving stars. Thus our results give a lower limit to the number of members in each possible stellar kinematic group. The beneﬁt of this approach is that we are excluding a large number of interlopers. We select the stars that have average U, V, W values within −1 −1 −1 the box. We then reject those that have σU >2kms ,σV >1kms and σW >3kms . We therefore limit the sample to only stars with relatively well-determined space velocities. Even though the average U, V, W values will place stars within the U, V, W box of a given SWP, the standard deviation in the space motions may give a signiﬁcant probability that the companion lies outside of the box. We treat the uncertainties using a Monte-Carlo draw, assuming a Gaussian distribution for the errors, centered on the average U, V, W

values, and with dispersions equal to σU , σV and σW . We produce 1000 random draws for each kinematic companion. A probability of kinematic membership, PKM, is computed by

incrementing a counter, Ci, by 1 each time the U, V, W of a companion falls within the kinematic box of the SWP. We then have PKM =Ci / 1000. Finally, we select only those stars that have PKM > 0.75 as the most secure members of a possible kinematic association.

3. Results: Candidate kinematic companions and the metallicity distribution

In Table 2 we give our derived velocity information for the SWPs and any Hipparcos stars that are kinematic companions based on the search parameters defined in the previous section. We find that 27 SWPs have at least one kinematic companion, 14 have three or more kinematic companions, and that two pairs of SWPs are kinematic companions with each other. If we compare Table 2 to Table 1 with the goal of finding matches in U, V and W 6, we find that 13 SWPs and their companions appear kinematically associated with known moving groups. Each of these possible matches will be examined on a case-by-case basis below. However, to estimate the probability that the SWP and SWP companion populations are physically linked, we compare their stellar abundances, which are unusually high for the SWP population. We take take only the F, G, and K stars and use only the Schuster & Nissen (1989) method for determining stellar abundances. As a control group, we take the 37 F, G, and K stars without known planets from Santos et al. (2001). We then find the companions to the control group using the method described in Section 2 and select only the F, G, and K spectral types for the metallicity test.

6We search for the closest matches in U and V, whereas a good match in the vertical components, W, is less critical. –5–

Figure 1 shows the cumulative [Fe/H] distributions for the four samples, as well as the cumulative distribution of metallicities for stars in the Hauck & Mermilliod (1998) catalog (N=22983). We also plot stars from the Hauck & Mermilliod (1998) catalog that survive our σU , σV ,andσW cut-off (N=1142) to understand if this constraint introduces bias in the selection of candidates. In fact, Figure 1 shows this sub-sample of Hauck & Mermilliod (1998) is slightly metal rich. This may reflect the observational bias in the Hipparcos catalog. Older, metal poor stars are dynamically heated away from the galactic plane and are under- represented in the solar neighborhood, where the Hipparcos parallaxes have the highest precision. The SWPs and their companions appear to comprise a distinct group from the stars without known planets and their companions (designated Ref. Sample 1 and Ref. Sample 1 Comp., respectively, in Fig. 1). The stars without planets and their companions are consistent with both Hauck & Mermilliod (1998) samples. Table 3 presents results of a Kolmogorov-Smirnov test of these metallicity distributions. Figure 1 and Table 3 confirm that the SWP sample is distinctly metal rich (Butler et al. 2000; Santos et al. 2001), but also suggests that the candidate kinematic companions are physically related to the SWP population. The metallicity test therefore indicates that some of the SWP kinematic groups identified in Table 2 constitute real physical associations. One possible source of bias is that the Santos et al. (2001) sample is limited to nearby stars, <17 pc, which might exclude a population of metal-rich stars, such as in the Hyades (d∼45 pc), and does not entirely overlap the volume occupied by most members in the SWP sample (10−50 pc). We therefore produce a new control group by randomly selecting 200 F, G, and K stars (B−V<0.9) from the Hipparcos+BBF sample with heliocentric distances between 10 and 50 pc. We find their kinematic companions (N=124) using the same criteria as before. The cumulative metallicity distribution of the new control sample (“Ref. Sample 2”) and their companions (“Ref. Sample 2 Comp.”) is given in Figure 2, and the Komogorov- Smirnov test results are shown in Table 3. This new test does not change our conclusion that the SWPs and their companions are drawn from the same parent distribution that is distinct from the control samples.

3.1. Stars with planets and the Hyades moving group: HD 1237, HD 17051, HD 75732, HD 108147, HD 120136 and HD 179949

These six SWPs are possible members of the Hyades moving group (Table 1). Chereul et al. (1999) deﬁne three velocity clumps, 2-10, 2-18, and 2-25 (Table 1) within the Hyades group. HD 1237 lies within clump 2-10 that has age 0.4−1.6 Gyr. HD 17051, HD 75732, and –6–

HD 120136 lie within clump 2-18, with a similar age range. HD 179949 lies close to clump 2-25, with a possible age 0.5−2.0 Gyr. If we relax our search constraint in the W velocity component, then HD 108147 lies closest to clump 2-25, and in fact shares two companions (HD 42341 and HD 151288) with HD 179949 (Table 2). HD 75732 (55 Cnc) and HD 120136 (τ Boo) are kinematic companions with each other, and share four companion stars between them that are listed as members of the Hyades Group (Eggen 1998, 1960b). We note that two stars in the Santos et al. (2001) control group, HD 7570 and HD 76151, are also possible member of the Hyades (Eggen 1985), and the latter star has as companions 55 Cnc, a companion to 55 Cnc (HD159876), and a companion to HD 120136 (HD 111998).

3.2. Gliese 876, HD 89744, HD 130322, HD 209458 and the Pleiades moving group

Six of the 11 kinematic companions to Gliese 876 are candidate members of the Pleiades moving group (Eggen 1998). The space velocity of Gliese 876 (Table 2) is consistent with Pleiades velocity clumps 2-5 (Chereul et al. 1999) and B3 (Asiain et al. 1999b), both of which are relatively old features of the Pleiades group (Table 1). The chromospheric inactivity of Gliese 876 gives it a probable age >1 Gyr (Marcy et al. 1998) that is within the range of ages given for clump 2-5 (Chereul et al. 1999). HD 89744 and HD 130322 also lie within the relatively older clumps 2-2 and B4 (Table 1), and the space motion of HD 209458 is near the U, V, W envelope of the Pleiades group (clumps 3-8 and B2; Table 1).

3.3. HD 27442 and HD 92788: Two isolated sister stars with planets?

Neither SWP is found to have kinematic companions, except for each other. Randich et al. (1999) give [Fe/H] = +0.22 and age 10 Gyr for HD 27442, which may be compared against [Fe/H] = +0.310.03 and age ∼6 Gyr for HD 92788 (Gonzalez et al. 2001). Given the uncertainties in age determinations, we presently do not know if their physical link should be excluded based on age alone. The possibility that HD 27442 and HD 92788 are sister stars with extrasolar planets requires further study of their dynamical and chemical characteristics. We note that such an isolated pairing does not occur in the Santos et al. (2001) control sample. –7–

3.4. HD 19994 and IC 2391

HD 19994 shares an identical V velocity component with HD 2630, a member of the IC 2391 moving group (Table 1; Eggen 1991). Ng & Bertelli (1998) estimate an age of 3.01.0 Gyr for HD 19994, which is consistent with the age range of IC 2391 members (Table 1 Chereul et al. 1999). Among the other seven kinematic companions, the metallicities of HD 123299 ([Fe/H]=0.80; Strobel et al. 1997) and HD 109141 ([Fe/H]=0.25) are comparable to [Fe/H]=0.26 recently published for HD 19994 (Santos et al. 2001). Within the Santos et al. (2001) control group three stars are kinematic members of IC 2391 (HD 30495, HD 74576, HD 42162). However, HD 19994 and the Santos et al. (2001) control group stars do not share companions between them.

3.5. HD 160691 and Centaurus-Crux

The U, V, W components of HD 160691 are consistent with those of the 0.2 Gyr Castor Group (Table 1). Two of the 12 kinematic companions to HD 160691 have also been identiﬁed as possible members of the Castor Group (HD 181321 and HD 210027; Barrado y Navascues 1998). However, the age of HD 160691, ∼6 Gyr (Lachaume et al. 1999; Butler et al. 2001), is inconsistent with the age of the Castor Group. A more plausible argument is that HD 160691 is a member of the Centaurus-Crux association (Table 1). Chereul et al. (1999) show that the age distribution of members peaks at 0.6 Gyr, but with a signiﬁcant tail of possible members between 1 and 3 Gyr.

3.6. HD 186427 and Wolf 630

The space velocities of HD 186427 fall within the range of the Wolf 630 moving group (Table 1), and both companions to HD 186427 are identiﬁed as possible members of this group (Eggen 1965). However, the reality that the Wolf 630 group has been challenged by several authors (McDonald & Hearnshaw 1983; Taylor 2000).

4. Summary

We use U, V, W space velocities derived from data in the Hipparcos and BBF catalogs to identify kinematic companions to stars with planets (Table 2). The number of companions for each SWP is a lower limit given the narrow search criteria. We relate 13 SWPs to known –8– stellar kinematic groups (Table 1) based on their common U, V, W motions, and the number of companions that have been previously identified as possible members of a SKG. The large inferred ages for the SWPs are typically inconsistent with the <1GyragesofSKGs. The probability that all the SWPs are interlopers in the known SKGs is diminished by the statistically significant finding that the kinematic companions to SWPs share their high metallicities (Fig. 1 and 2). We test the possibility that our initial sample and search method is biased toward selecting high metallicity stars. We repeat our experiment on a control group of stars without planets and find that the companions to the control group share their relatively low metallicities. We conclude that several SWPs with kinematic companions are members of real (co-eval) stellar groups.

Acknowledgements:We are grateful for support from the NSF Center for Adaptive Optics and AURA. We beneﬁted greatly from discussions with Debra Fisher, Geoﬀ Marcy and Greg Laughlin. David Nidever kindly provided absolute radial velocities for stars with planets from the Keck and Lick planet search programs.

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This preprint was prepared with the AAS LATEX macros v5.0. –11–

Fig. 1.— The cumulative functions for only the F, G, and K stars in the following samples: SWPs (N=47)=black; SWP companions (N=37)=orange; Ref. Sample 1 (stars without planets, N=39) from Santos et al. (2001)=red; Ref. Sample 1 Comp. (companions to stars without planets, N=56)=green; Hauck & Mermilliod (1998) catalog (N=22983)=solid thin gray; kinematic subsample of Hauck & Mermilliod (1998) catalog(N=1142)=dashed thin gray. The results of Kolmogorov-Smirnov tests on these samples is given in Table 3. The black and red lines confirm the analysis of Santos et al. (2001) for stars with and without planets, respectively. Our key finding is that the companions to these two populations also show a distinct metallicity difference. –12–

Fig. 2.— Same as Figure 1, except we use a new control group “Ref. Sample 2” and companions to the new control group “Ref. Sample 2 Comp.”, as discussed in the text. –13–

Table 1. Several Known Stellar Kinematic Groups.

Name† Reference U,V,W(kms−1) Age (Gyr) [Fe/H]

Cen-Crux Chereul et al. (1999) −13.1 6.2, −7.9 6.1, −9.3 5.51···

Castor Barrado y Navascues (1998) −10.7 3.5, −8.0 2.4, −9.7 3.00.2···

Hyades Eggen (1982) −40.5 2.3, −18.4 2.3, −4.9 6.00.26 ··· Chen et al. (1997) −45.5 7.7, −25.4 13.0, 0.0 10.31.25 0.3 ··· Perryman et al. (1998) −41.73 0.14, −19.29 0.11, −1.06 0.10 0.625 0.050 0.14 0.05 3-10 Chereul et al. (1999) −32.9 6.6, −14.5 6.8, −5.6 6.50.4−2.0 ··· 2-10 Chereul et al. (1999) −31.6 2.8, −15.8 2.8, 0.8 2.70.4−1.6 ··· 2-18 Chereul et al. (1999) −33.0 4.2, −14.1 4.0, −5.1 3.10.4−1.6 ··· 2-25 Chereul et al. (1999) −32.8 2.8, −11.8 2.8, −8.9 2.90.5−2.0 ··· D Asiain et al. (1999a) −32.0 6.0, −14.0 4.2, −6.0 6.70.56 0.17 ···

IC 2391 Eggen (1991) −22.4 1, −17.5 1, −9.4 10.08−0.25 -0.1 Chen et al. (1997) −20.1 8.5, −12.0 5.6, −5.2 4.70.46 0.16 ··· Chereul et al. (1999) −20.8 4.3, −14.5 4.9, −4.9 5.00.6−2.0 ··· C2 Asiain et al. (1999a) −17.1 5.6, −12.0 3.4, −5.7 4.30.28 0.12 ···

Pleiades Chen et al. (1997) −5.9 6.2, −26.5 4.3, −6.1 4.80.11 0.07 ··· 3-8 Chereul et al. (1999) −14.4 8.4, −20.1 5.9, −6.2 6.30.6−1.0 ··· 2-2 Chereul et al. (1999) −7.5 4.6, −24.6 3.5, −10.2 3.50.6−1.0 ··· 2-5 Chereul et al. (1999) −12.0 5.3, −21.6 4.7, −5.3 5.90.5−2.0 ··· 1-6 Chereul et al. (1999) −13.1 3.1, −21.9 3.3, −7.1 2.51.0 ··· 1-7 Chereul et al. (1999) −11.1 1.7, −21.9 3.0, −6.0 1.80.01 ··· B1 Asiain et al. (1999a,b) −4.5 4.7, −20.1 3.3, −5.5 1.90.02 0.01 ··· B2 Asiain et al. (1999a) −10.7 5.3, −18.8 3.7, −5.6 2.20.06 0.02 ··· B3 Asiain et al. (1999a) −16.8 5.1, −21.7 2.7, −5.6 4.60.30 0.12 ··· B4 Asiain et al. (1999a) −8.7 4.8, −26.4 3.3, −8.5 4.70.15 0.05 ···

Wolf 630 Eggen (1983) 16.8 7.9, −30.2 0.4, −8.8 10.6 ··· −0.25

†Indented designations represent sub-structure in the kinematic group, as named by the authors in column 2 references, that may also represent parts of the group born at diﬀerent times. –14–

Table 2. Stars with planets†and their kinematic companions

a b c d e f Name SpT PKM U VWσVσUσW[Fe/H]ph [Fe/H]spec Ages

1237 G6V ··· -33.09 -16.42 2.43 0.29 0.19 0.03 -0.06 0.11 0.08 ··· 0.6 28069 F5 1.00 -32.43 -16.68 0.77 0.38 0.54 0.66 ··· ··· ··· 59037 A4V 0.95 -34.99 -15.72 1.03 1.12 0.53 0.74 ··· ··· ··· 1835H G3V 0.82 -35.73 -14.77 0.16 0.67 0.29 0.39 0.07 ··· ··· 127739H F2IV 0.88 -31.09 -15.26 1.49 1.15 0.58 1.21 0.15 ··· ··· 29225H F5V 0.91 -35.42 -16.67 -0.27 1.14 0.68 0.67 ··· ··· ··· 88693 K2IIICN 0.86 -31.26 -16.42 4.22 1.95 0.34 0.30 ··· ··· ··· Gl 669A M4 0.81 -33.30 -15.18 1.11 1.47 0.83 1.30 ··· ··· ··· 210434 K0III-IV 0.76 -32.14 -15.45 -2.26 1.89 0.50 1.34 ··· ··· ··· 6434 G3IV ··· 85.18 -66.96 -2.59 3.00 2.24 0.71 -0.54 −0.55 0.07 ··· 8574 F8 ··· -44.10 -36.76 -30.92 1.23 1.76 0.75 -0.24 ··· ··· 9826 F8V ··· 28.95 -22.67 -14.06 0.17 0.14 0.25 -0.04 0.12GL ··· 10697 G5IV ··· 36.77 -28.22 17.04 0.32 0.21 0.38 0.08 0.16G1 7.8 0.5; 6.0 12661 K0 ··· 51.77 -29.54 2.31 0.65 0.22 0.91 ··· 0.16G1 8 1; 8.4 13445 K0V ··· -97.41 -75.58 -29.54 0.67 0.33 0.14 ··· −0.20 0.06 ··· 16141 G5IV ··· 84.53 -41.26 1.55 2.80 1.92 2.03 -0.02 0.15 0.05 8.5 0.5; 6.7 17051 G3IV ··· -31.18 -16.61 -7.57 0.30 0.64 1.02 0.06 0.25 0.06 1 1; 1.6 25998 F7V 0.97 -32.67 -16.07 -8.36 0.48 0.44 0.12 0.07 ··· ··· 25893 G5 0.94 -32.86 -17.24 -9.38 0.35 0.64 0.15 -0.23 ··· ··· 148786H G8/K0III 0.78 -33.52 -17.65 -9.43 0.48 0.89 0.31 ··· 0.14 0.06T ··· 222143 G5 0.84 -33.73 -15.90 -12.01 0.67 0.70 0.29 -0.02 ··· ··· 27604 A8V+... 0.85 -31.50 -17.45 -7.18 1.15 0.87 0.89 ··· ··· ··· 64379H F3/F5V 0.96 -33.52 -15.99 -5.88 0.29 0.48 0.06 0.10 ··· ··· Gl 494 M2 0.91 -29.19 -17.35 -9.84 0.53 0.43 1.26 ··· ··· ··· 19994 F8V ··· -20.49 -19.50 -6.95 0.14 0.33 0.13 -0.01 0.23 0.06 3 1N 45239 A4V 0.93 -22.59 -20.12 -6.45 1.00 0.83 0.57 ··· ··· ··· 115892 A2V 0.99 -21.85 -20.25 -3.43 0.41 0.44 0.23 ··· ··· ··· 2630 F2/F3V 0.94 -22.04 -19.50 -8.69 0.83 0.91 2.05 -0.23 -0.17S ··· 34045 A9II/III 0.84 -22.25 -18.73 -11.49 1.30 0.96 0.89 ··· ··· ··· 70302 G8/K0III 0.80 -21.00 -20.24 -10.69 1.62 0.73 2.29 ··· ··· ··· 113337 F6V 0.78 -23.97 -19.68 -10.09 0.66 0.68 0.97 0.05 0.07S ··· 123299 A0III 0.82 -20.18 -20.66 -8.07 1.20 0.95 0.95 ··· 0.80S ··· 109141 F3IV/V 0.83 -18.23 -18.47 -8.75 0.62 0.89 0.93 0.25 ··· ··· 22049 K2V ··· -3.39 7.17 -20.41 0.13 0.05 0.15 ··· −0.07 0.06 ··· 70267 F5V 0.97 -2.02 6.10 -19.51 0.17 0.51 0.74 -0.07 ··· ··· 215729 A2V 0.86 -0.46 7.32 -17.03 0.81 0.98 1.19 ··· ··· ··· 105698 F9V 0.96 -2.81 7.87 -22.05 0.60 0.55 2.07 ··· ··· ··· 120602 K0 0.99 -5.45 7.98 -23.01 0.77 0.61 1.10 ··· ··· ··· 91437 G6/G8III 0.99 -0.30 6.82 -17.20 0.24 0.25 1.19 ··· −0.08 0.09T ··· 27442 K2IV ··· 15.14 -22.07 -19.22 0.14 0.37 0.34 ··· ··· ··· 92788 G5 0.98 16.12 -22.27 -20.82 0.51 0.81 0.57 0.29 ··· ··· 28185 G5 ··· -33.58 -34.78 -23.35 0.16 0.76 0.33 0.15 0.24 0.05 ··· 37124 G4IV-V ··· 32.72 -46.09 -43.33 0.38 1.86 1.76 -0.37 -0.41G1 ··· 3.9 38529 G4V ··· -13.50 -25.11 -34.20 0.52 0.53 1.06 0.23 0.39 0.06 3 0.5; 3.7 46375 K1IV ··· 10.38 -19.40 8.91 0.34 0.72 0.35 ··· 0.21G1 4.5 50554 F8 ··· 3.65 -9.99 -11.52 0.04 0.36 0.37 -0.14 ··· ··· 9525 K1/K2III 0.94 4.56 -8.87 -11.11 0.41 0.55 1.17 ··· ··· ··· 195569 K0III 0.82 3.65 -11.19 -8.65 1.00 0.60 0.78 ··· ··· ··· 52619 F3/F5V 1.00 4.48 -9.83 -14.00 0.46 0.37 0.57 -0.06 ··· ··· 66216 K2III 0.75 2.79 -8.77 -16.36 1.08 0.74 0.99 ··· 0.10 0.12T ··· 22663 K0III 0.93 0.54 -9.13 -8.36 0.37 0.67 0.97 ··· ··· ··· Gl 678.1A M1V... 0.78 1.22 -10.53 -8.49 1.65 0.90 0.71 ··· ··· ··· 30610 K0/K1III 0.80 4.13 -8.40 -13.92 0.44 0.34 0.41 ··· ··· ··· 136726 K4III 0.97 0.64 -8.97 -14.52 0.34 0.44 0.45 ··· −0.02 0.08T ··· –15–

Table 2—Continued

a b c d e f Name SpT PKM U VWσVσUσW[Fe/H]ph [Fe/H]spec Ages

52265 G0III-IV ··· -52.28 -20.64 -9.18 0.25 0.31 0.22 0.07 0.22 0.07 2.1 0.3; 4.0 2025 K2V 0.93 -52.38 -21.80 -9.62 1.03 0.44 1.20 ··· ··· ··· 74156 G0 ··· 28.52 -51.85 -18.32 2.22 3.53 1.46 -0.06 ··· ··· 75289 G0Ia0: ··· 20.91 -12.63 -21.74 0.36 0.06 0.36 0.08 0.27 0.06 ··· 75732 G8V ··· -37.07 -18.01 -8.17 0.23 0.14 0.29 0.10 0.45GV ··· 164764 F5V+... 0.78 -33.81 -19.05 -12.43 0.86 0.45 0.46 ··· ··· ··· 159876H F0IIIp 1.00 -39.57 -18.76 -6.25 0.49 0.41 0.20 ··· ··· ··· 120136 F7V 0.86 -33.53 -18.86 -6.86 0.35 0.21 0.49 0.12 ··· ··· 38170 B9/B9.5V 0.81 -39.68 -17.43 -8.07 1.47 0.67 0.59 ··· ··· ··· 113226H G8IIIvar 0.99 -38.01 -17.66 -11.01 0.97 0.58 0.39 ··· 0.04 0.04T ··· 148786 G8/K0III 0.81 -33.52 -17.65 -9.43 0.48 0.89 0.31 ··· 0.14 0.06T ··· 161321 A3m 0.90 -34.94 -17.65 -8.02 1.17 0.92 0.86 ··· ··· ··· 18692H F3V 0.93 -35.85 -17.37 -9.34 1.16 0.76 2.22 0.10 ··· ··· 121164 A7V 0.76 -35.66 -18.94 -4.57 1.73 0.90 1.43 ··· ··· ··· 80606 G5 ··· 6.77 2.81 11.54 3.40 1.32 3.25 0.20 0.43N1 ··· 82943 G0 ··· 10.24 -19.85 -8.90 0.32 0.31 0.31 0.27 0.33 0.06 ··· 83443 K0V ··· 19.88 -30.66 -11.97 0.80 0.08 0.62 ··· 0.39 0.09 ··· 43834 G5V 0.98 18.84 -29.50 -11.50 0.13 0.42 0.24 0.12 0.01S 7.2L 89744 F7V ··· -11.25 -29.58 -13.25 0.41 0.81 0.30 0.13 0.30G1 1.8 0.1; 8.4 25457 F5V 0.91 -8.61 -28.70 -12.45 0.33 0.39 0.25 -0.01 ··· ··· Gl 393 M2 0.82 -7.78 -29.09 -15.23 0.20 0.52 0.55 ··· 0.24 ··· ··· G1 +1.5 92788 G5 16.12 -22.27 -20.82 0.51 0.81 0.57 0.22 0.31 4.2−2.0;6.4 27442 K2IV 0.97 15.14 -22.07 -19.22 0.14 0.37 0.34 ··· ··· ··· 95128 G0V ··· -24.02 -2.42 0.60 0.18 0.04 0.10 ··· 0.01G8 ··· 20630 G5Vvar 0.93 -21.74 -4.33 -4.73 0.16 0.05 0.15 -0.02 ··· ··· 106252 G0 ··· 28.53 -43.62 0.56 0.98 1.32 0.48 -0.13 ··· ··· 108147 F8/G0V ··· -30.31 -11.36 -14.28 0.75 0.42 0.40 -0.02 0.20 0.06 ··· 4128 K0III 1.00 -30.63 -11.46 -13.09 0.73 0.34 0.49 ··· -0.05S ··· 33924 F5 0.93 -30.37 -11.14 -14.88 1.18 0.93 0.76 -0.01 ··· ··· 151288 K7V 1.00 -29.43 -12.26 -16.22 0.17 0.14 0.13 ··· ··· ··· 30606 F8V 0.86 -29.79 -12.53 -16.47 0.84 0.59 0.69 0.04 -0.01S ··· 189118 A4/A5IV 0.90 -27.69 -11.76 -16.31 0.69 0.45 1.08 ··· ··· ··· 164258 A3spe... 0.88 -29.88 -10.65 -17.52 1.06 0.86 1.30 ··· ··· ··· 42341 K2III 0.81 -29.14 -12.02 -8.98 0.92 0.86 0.38 ··· 0.14 0.09T ··· 114762 F9V ··· -82.69 -69.59 58.01 5.31 3.80 0.56 -0.75 ··· ··· 117176 G5V ··· 13.10 -51.83 -4.18 0.18 0.68 0.22 -0.08 -0.03G8 ··· 120136 F7V ··· -33.79 -18.86 -7.76 0.33 0.21 0.21 0.17 0.32GL ··· 62781 F0IV 0.96 -31.54 -18.88 -8.44 0.58 0.86 0.18 ··· ··· ··· Gl 806 M3 0.78 -30.94 -20.13 -10.32 0.57 0.70 0.21 ··· ··· ··· 164764 F5V+... 1.00 -33.81 -19.05 -12.43 0.86 0.45 0.46 ··· ··· ··· 204485H F0V 0.85 -35.71 -20.02 -2.27 0.93 0.49 0.28 ··· ··· ··· 22496H K7V 0.80 -31.48 -20.16 -4.24 0.36 0.73 0.95 ··· ··· ··· 111998H F5V 0.92 -35.80 -19.63 -6.12 0.93 0.77 1.03 0.06 ··· ··· 148786 G8/K0III 0.78 -33.52 -17.65 -9.43 0.48 0.89 0.31 ··· 0.14 0.06T ··· 161321 A3m 0.80 -34.94 -17.65 -8.02 1.17 0.92 0.86 ··· ··· ··· 75732 G8V 0.75 -37.53 -18.15 -7.81 0.23 0.14 0.29 0.10 ··· ··· 121164H A7V 0.85 -35.66 -18.94 -4.57 1.73 0.90 1.43 ··· ··· ··· 121504 G2V ··· -27.84 -51.89 -2.02 1.65 1.52 0.23 -0.02 0.17 0.06 ··· 130322 K0III ··· -9.44 -25.99 -11.00 0.17 1.22 0.13 -0.02 0.05G1 ··· 0.3 –16–

Table 2—Continued

a b c d e f Name SpT PKM U VWσVσU σW [Fe/H]ph [Fe/H]spec Ages

··· G1 +1 134987 G5V -20.66 -40.13 20.64 0.63 0.98 0.47 0.22 0.32 9−3.5;5.8 141937 G2/G3V ··· 2.91 13.34 -8.63 0.22 0.50 0.30 0.24 ··· ··· 140573 K2III 1.00 5.86 13.47 -4.69 0.29 0.23 0.30 ··· 0.10 0.03T ··· 4058 A5V 0.81 0.38 11.85 -12.37 0.38 0.42 0.39 ··· ··· ··· 19656 K1III 0.81 0.79 12.22 -5.99 0.98 0.86 0.49 ··· −0.08 0.06 ··· 4247 F0V 0.84 1.35 14.76 -11.06 0.10 0.29 1.10 -0.29 ··· ··· 143761 G2V ··· 54.31 -35.84 20.75 0.59 0.56 0.11 -0.27 -0.29G8 ··· 145675 K0V ··· 23.84 -12.23 -16.20 0.29 0.05 0.07 ··· 0.50G9 ··· 160691 G5V ··· -13.69 -8.36 -4.08 1.11 0.43 0.26 0.20 ··· ··· 213442 M4III 0.82 -15.48 -9.62 -2.23 0.74 0.59 0.45 ··· ··· ··· 137422 A3II-III 0.88 -15.67 -8.71 -2.15 1.17 0.59 0.42 ··· ··· ··· 219482 F7V 0.84 -15.44 -7.35 -3.44 0.88 0.71 1.42 -0.19 ··· ··· 173650 B9p 0.84 -12.34 -9.16 -7.64 0.87 0.99 0.90 ··· -0.76S ··· 181321 G1/G2V 0.99 -12.97 -8.32 -6.59 1.13 0.34 0.62 -0.20 ··· ··· 21626 G0IV 0.86 -15.16 -7.91 0.57 0.63 0.70 1.01 -0.17 ··· ··· 23258 A0V 0.87 -14.94 -7.41 -3.39 1.17 0.71 0.64 ··· ··· ··· 62857 G5IV 0.94 -14.06 -7.77 -0.52 1.70 0.53 0.84 ··· ··· ··· 188385 A2V 0.81 -16.02 -8.96 -6.58 0.91 0.90 0.77 ··· ··· ··· 210027 F5V 0.82 -14.74 -6.97 -6.34 0.14 0.45 0.22 -0.05 -0.10S ··· 28246 F6V 0.79 -15.32 -7.30 -6.07 0.41 0.81 0.84 0.08 ··· ··· 170384 A3V 0.75 -16.26 -9.15 -0.11 1.26 0.72 0.48 ··· ··· ··· 168443 G5 ··· -29.96 -57.69 -6.67 0.50 1.31 0.20 -0.06 0.10G1 10.5 1.5; 7.4 168746 G5 ··· -28.91 -25.38 -3.37 0.20 0.59 0.21 -0.09 −0.06 0.05 ··· 68290 K0III 0.80 -25.88 -26.11 2.29 0.41 0.49 0.26 ··· 0.04 0.07T ··· 169830 F8V ··· -16.95 1.18 3.83 0.03 0.16 0.20 ··· 0.22 0.05 ··· 4391 G5IV 0.90 -16.08 0.68 8.46 0.29 0.34 1.12 -0.21 ··· ··· 99167 K5III 0.99 -17.47 2.13 5.07 1.48 0.46 0.47 ··· -0.320.08T ··· ··· ··· G1 4 177830 K0 -23.21 -70.44 -7.17 0.69 0.46 0.22 0.36 11−3.5;13.5 178911 G1V ··· -58.44 -19.41 1.06 3.30 1.31 0.82 0.11 ··· ··· 179949 F8V ··· -27.38 -12.86 -11.06 0.75 0.25 0.46 0.062 ··· ··· 64486 A0p... 0.75 -26.36 -14.19 -9.05 1.35 0.91 0.63 ··· ··· ··· 151288 K7V 0.95 -29.43 -12.26 -16.22 0.17 0.14 0.13 ··· ··· ··· 25680 G5V 0.98 -25.11 -13.35 -6.47 0.28 0.25 0.13 -0.02 ··· ··· 42341 K2III 0.89 -29.14 -12.02 -8.98 0.92 0.86 0.38 ··· 0.14 0.09T ··· 186427 G5V ··· 17.63 -30.44 -1.90 0.24 0.20 0.09 0.07 0.07LG ··· 166620W K2V 0.99 16.97 -31.05 0.20 0.19 0.27 0.13 ··· ··· ··· 161797W G5IV 0.99 16.69 -30.82 -5.41 0.26 0.30 0.17 0.17 ··· ··· 187123 G5 ··· 2.60 -15.40 -43.43 0.32 0.06 1.44 0.17 0.16G9 ··· 22484H F9V 1.00 1.55 -15.15 -41.73 0.44 0.15 0.42 -0.22 0.37S 6.51N ;5.2L 190228 G5IV ··· -20.04 -47.03 -35.86 0.16 0.09 1.87 -0.27 −0.24 0.06 ··· 115617 G5V 0.81 -23.29 -47.40 -31.43 0.15 0.33 0.21 0.07 ··· 9.01.4N ;6.6L 192263 K0 ··· -16.48 10.11 19.76 0.22 0.39 0.39 ··· -0.03G1 ··· 0.3 195019 G3IV-V ··· -71.99 -75.60 -37.45 0.96 0.12 1.86 -0.11 ··· ··· 209458 F8 ··· -5.70 -15.61 0.56 0.25 0.18 0.36 -0.17 0.04G1 31;4.3 38385 F3V 0.90 -5.89 -16.73 4.04 0.33 0.66 0.51 -0.06 ··· ··· 208057 B3V 0.78 -8.21 -16.80 2.47 0.75 0.94 0.71 ··· ··· ··· 136359 F7V 0.88 -5.98 -16.55 3.85 0.98 0.87 0.19 -0.19 -0.14S ··· 210277 G0 ··· 3.95 -50.18 -6.24 0.22 0.66 0.37 0.16 0.23 0.05 ··· 81101 G6III 0.92 6.30 -49.41 -11.01 0.20 0.49 0.20 ··· ··· ··· –17–

Table 2—Continued

a b c d e f Name SpT PKM U VWσVσUσW[Fe/H]ph [Fe/H]spec Ages

Gl 876 M5 ··· -12.60 -20.02 -11.39 0.14 0.19 0.14 ··· ··· ··· 139664P F5IV-V 0.91 -15.03 -19.73 -9.85 1.06 0.63 0.22 -0.16 ··· ··· 224617 F4IV 0.85 -12.14 -20.07 -16.78 0.37 0.72 0.63 -0.11 -0.27S ··· 128898P F1Vp 1.00 -10.67 -19.29 -11.02 0.38 0.38 0.11 0.13S ··· ··· 221503P K5/M0V 0.97 -13.23 -20.98 -10.43 0.34 0.53 1.04 ··· ··· ··· 213845P F7V 0.99 -15.30 -20.85 -12.54 0.39 0.41 0.65 -0.00 ··· ··· 38206 A0V 0.88 -13.66 -21.24 -6.15 0.46 0.51 0.37 ··· 0.06S ··· 206860P G0V 1.00 -14.55 -20.99 -11.13 0.19 0.28 0.34 -0.12 ··· ··· 195961 Fm 0.99 -10.96 -19.91 -15.53 0.74 0.69 0.51 1.44 ··· ··· 10830 F2IV 0.83 -12.31 -21.42 -8.92 0.44 0.59 1.66 -0.02 ··· ··· 166P K0V 0.88 -14.95 -21.59 -10.06 0.20 0.29 0.22 ··· ··· ··· 11025 K0III 0.90 -11.96 -20.17 -16.12 1.25 0.97 0.78 ··· ··· ··· 213240 G4IV ··· 25.14 -30.19 23.32 0.84 1.00 0.76 -0.02 ··· ··· 217014 G5V ··· -15.24 -29.64 15.66 0.18 0.04 0.05 0.18 0.21G1 5.5 0.5; 7.1 209960 K4III 0.86 -14.36 -28.24 15.65 0.95 0.59 0.85 ··· −0.03 0.06T ··· 217107 G8IV ··· -1.48 -8.54 10.36 0.07 0.06 0.05 0.28 0.40 0.06 12 1.5; 5.6 145921 K2III 0.98 0.03 -9.43 6.30 0.34 0.59 0.50 ··· ··· ··· 107418 K0III 0.99 0.87 -7.49 12.24 0.25 0.39 0.47 ··· −0.08 0.07T ··· 111239 M4III 0.92 -3.73 -8.19 6.71 0.96 0.96 1.12 ··· ··· ··· 36848 K2/K3III 0.91 2.13 -7.34 10.42 0.23 0.45 0.39 ··· ··· ··· 222582 G5 ··· 36.67 -0.60 -11.05 1.69 0.32 0.10 -0.08 0.02G1 11 1; 5.6

†Stars with planets in bold type. aHenry Draper designations. If star not in HD Catalog, then Gliese Catalog number used. Superscripts indicate that star has been studied as possible members of moving groups: H (Hyades), P (Pleiades), W (Wolf 630). bProbability of kinematic membership with the SWP. Discussed in section 2. cU, V, W space velocities in km s−1 with U directed toward galactic center. dDerived from Schuster & Nissen (1989) for F and G stars only. eMetallicity followed by references: no superscript=Santos, Israelian & Mayor 2001; G1=Gonzalez et al. 2001; G9=Gonzalez 1999; G8=Gonzalez 1998; GL=Gonzalez & Laws 2000; GV=Gonzalez & Vanture 1998; N1=Naef et al. 2001; LG=Laws & Gonzalez 2001; S=Strobel et al. 1997; T=Taylor 1999. The metallicity of Gl393 is given in Eggen (1996). f Ages in 109 yr. Values without superscripts are from Gonzalez et al. (2001) with the ﬁrst value (includes estimate) derived from Schaller et al. (1992) and Schaerer et al. (1993) stellar evolutionary isochrones, and the second value derived from Henry et al. (1996). Other references as superscripts: N = Ng & Bertelli (1998), L = Lauchaume et al. (1999) –18–

Table 3. Kolmogorov-Smirnov Test Results on the Metallicity Distributions

a Sample 1 Sample 2 PKS

SWPs SWP Kinematic Companions† 0.430 SWPs Ref. Sample 1 (Santos et al. 2001) 3.3 × 10−5 SWPs Ref. Sample 2 1.99 × 10−5 SWP Kinematic Companions† Hauck & Mermilliod (1998)† 2.04 × 10−4 SWP Kinematic Companions† Ref. Sample 1 Comp.† 1.28 × 10−2 SWP Kinematic Companions† Ref. Sample 2 Comp.† 2.68 × 10−5 Ref. Sample 1 (Santos et al. 2001) Ref. Sample 1 Comp.† 0.344 Ref. Sample 1 Comp.† Hauck & Mermilliod (1998)† 0.101

aThe probability of the two observed distributions being drawn from the same parent distribution. † −1 Sub-sample derived after (σU ,σV ,σW)<(2,1,3) km s cut-oﬀ.