in WDS, kindly provided by Dr. B. Mason). Furthermore, there are significant differences between the short term (3.25 yr baseline) proper motion measured by HIPPARCOS (van Leeuwen 2007) and the long term proper motion which includes old photographic plates (e.g. Tycho2, Høg et al. 2000). This supports an orbital period of a few years for the SB. In the ASAS photometry, the two components are indistinguishable from HIP 25434 (ASAS 052623-4322.6; 1SWASP+J052622.97-432236.2). We find a significant period $P = 5.34$ d in only one ASAS season and $P = 6.6$ d in the SuperWASP data (only 59 measurements available). These periods are “uncertain” and the component to which they belong is ambiguous. Considering the early spectral type of the primary, they are more likely due to photometric variations of the secondary, HIP 25434. However, they are both inconsistent with secondary’s stellar radius and $v \sin i$, and would imply an age much older than that derived from other methods. Moór et al. (2013) propose membership to the Columba association. The space velocities and association to groups depend sensitively on the adopted proper motion. Using the HIPPARCOS proper motion, the kinematics are only consistent with the Nearby Young Population. Adopting the Tycho2 proper motion results in a high membership probability to the Columba association using the Malo et al. (2013) and Gagné et al. (2014) Bayesian analysis tools. Considering that the HIPPARCOS astrometry is likely biased by the astrometric motion of the additional component orbiting HIP 25436, the Tycho2 proper motion should be preferred. The age indicators are consistent with Columba membership.

TYC 9162-0698-1 = HD 269620 (ASAS 052927-6852.1) The star’s kinematics match Tuc/Hor, Columba, and Carina at <2.0 sigma. The estimated age of the star is also broadly consistent with the ages of these groups, as all age indicators are within the distribution of known members. The Malo et al. (2013) Bayesian analysis predicts an 85% probability of the star being a member of Columba at a distance of 93.5 pc. This is close to the photometric distance estimate of 98.7 pc. Membership to the Columba association was also recently proposed by Moór et al. (2013). On the other hand, Gagné et al. (2014) BANYAN II web tool does not confirm this assignment, suggesting a possible membership to Carina (15%) or the field. The star is projected in front of the LMC. Kiraga (2012) finds a photometric rotation period $P = 2.613$. We also find the same period $P = 2.61$ d either from Lomb-Scargle or Clean analysis.

TYC 5346-0132-1 = BD-8 1195: (ASAS 053835-0856.7) Proposed as a member of Columba by Torres et al. (2008). At the <2.0 sigma level, its kinematics match TWA, Columba, and η Cha. However, the target’s distance and position in the sky are inconsistent with TWA or η Cha membership. The age indicators are also more consistent with Columba than the other groups. Thus, the analysis reinforces the Columba membership assignment. The Malo et al. (2013) tools predict 100% probability of Columba membership at a distance of 80.5 pc. This predicted distance for membership is nearly equal to our photometric distance of 81.2 pc. The Gagné et al. (2014) on line tool yields a probability of 53.6%. ROSAT shows no X-ray counterparts within the adopted matching radius of 30 arcsec, but the bright X-ray source 1RXS J053835.1-085639 lies just above the threshold (angular distance of 32.5 arcsec from the optical source). The position of the X-ray source XMMSL1 J053834.6-085645 is 6 arcsec apart from TYC 5346-0132-1, suggesting that

1RXS J053835.1-085639 is associated to TYC 5346-0132-1. The photometric period $P = 1.983$ d is found by both the Lomb-Scargle and the Clean analysis at high confidence level and in good agreement with the earlier determination by Kiraga (2012).

HIP 30261 = HD 44748: (ASAS 062157-3430.7; 1SWASP+J062157.25-343043.7) This target’s kinematics do not match at the <2.0 sigma level any of the investigated groups and associations. The kinematics are also not consistent with the nearby, young population. The star is estimated to be quite young (60 Myr) based on lithium and estimated to be slightly older than the Pleiades based on other indicators. With either a Scargle-Lomb or Clean analysis, the photometric period $P = 4.16$ d is found in almost all the ASAS seasons and all the SuperWASP data. The same rotation period was also found by Kiraga (2012).

TYC 7617-0549-1 = CD-40 2458: (ASAS 062607-4102.9) Proposed as a 70% probability member of Columba by Torres et al. (2008). At the <1.0 sigma level, its kinematics match both Columba and Carina. However, the target’s X galactic distance is inconsistent with other Carina members, which have a relatively tight distribution. The age of the star is broadly consistent with the Columba association. Thus, the analysis reinforces the Columba membership assignment. The Malo et al. (2013) and Gagné et al. (2014) Bayesian analysis tools predict 100% probability of Columba membership at a distance of 77.5 pc. This predicted distance for membership is nearly equal to our photometric distance of 77.8 pc. Messina et al. (2010) found a rotation period $P = 4.13$ d in ASAS data and $P = 4.14$ d in SuperWASP data (Messina et al. 2011). This was subsequently confirmed by Kiraga (2012).

TYC 9181-0466-1 = HD 47875: (ASAS 063441-6953.1) New close visual binary from our program ($\Delta H = 1.5$ mag at 1.89 arcsec). All indicators are consistent with an age younger than 100 Myr, but there is no previously published association with MGs. The target’s kinematics match Tuc/Hor and TWA at the <2.0 sigma level. However, its position on the sky and estimated age reject it as a TWA member. The Malo et al. (2013) Bayesian analysis predicts a 97% chance of it being a Tuc/Hor member at 65.5 pc, which is not so different from our photometric distance of 77.7 pc (including a correction for binarity). Thus, the star might be a previously unrecognized member of Tuc/Hor. However, the updated BANYAN II web tool does not support the Tuc-Hor membership. With both period search methods, we find $P = 2.77$ d to be the most significant period in most seasons. A second period $P = 1.56$ d has comparable power in several seasons. Considering $v \sin i = 13.5$ km s⁻¹ and stellar radius $R = 1.075 R_⊙$, we infer rotation axis inclination values of $i = 43°$ and $i = 22°$, respectively. The observed maximum light curve amplitude up to $\Delta V = 0.04$ mag is more compatible with the longer period $P = 2.77$ d.

HIP 32235 = HD 49855: (ASAS 064346-7158.6) Proposed as a bona fide member of Carina by Torres et al. (2008) and Malo et al. (2013). Its kinematics match both Columba and Carina at the <2.0 sigma level, and the membership to Carina was fully supported by Gagné et al. (2014) on-line tool. The target’s YZ galactic distances differ slightly from what is expected for Columba. The age is consistent with both Columba and Carina. Thus, the analysis reinforces the Carina membership assignment. Messina et al. (2010) found a rotation period $P = 3.83$ d in ASAS data, which is subsequently confirmed by Kiraga (2012).
HIP 35564 = HD 57852 = HR 2813: (ASAS 072021-5218.7) Fast-rotating early-type star, proposed as a member of Carina-Near moving group by Zuckerman et al. (2006). The target's kinematics match the Carina-Near group at the <1.0 sigma level and show no indication of matching any other group. The age estimates are also consistent with the age of this group. Thus, the Zuckerman et al. membership assignment is confirmed. The RV measurements show a scatter of a few km s⁻¹ when combining data from several sources, indicating it is an SB. The CCF shows a broad profile with no indication of additional components. The star also exhibits non-periodic photometric variability. It has a moderately wide (9 arcsec projected separation) companion HD 57853 = HR 2814, a late F star which is a spectroscopic triple (see Saar et al. 1990; Desidera et al. 2006). The total mass of the close triple was estimated to be about 2.4 M☉ (Saar et al. 1990). The system is therefore a hierarchical quintuple.

TYC 8128-1946-1 = CD-482972 (ASAS 072823-4908.4) Proposed as a 100% probability member of Argus by Torres et al. (2008). At the <1.0 sigma level, its kinematics match both the Argus association and IC 2391 cluster. The age diagnostics support a young age, compatible with Argus membership. The Malo et al. (2013) Bayesian analysis tools with our adopted parameters as input predict 100% probability of Argus membership at a distance of 76.5 pc. On the other hand, membership is rejected by the Gagné et al. (2014) online tool. The FEROS RV by SACY and our measurement made with CORALIE differ from one another by 3.1 km s⁻¹. Considering the large v sin i of the star, we consider it a possible SB. Additional measurements are needed for confirmation of binarity. Messina et al. (2011) report a rotation period P = 1.038 d, subsequently confirmed by Kiraga (2012). HIP 36312 = HD 59659 is an F7 star at 81 arcsec from TYC 8128-1946-1. According to Torres et al. (2008), the proper motions and distances are compatible with a physical association, but no spectroscopy was available to them to confirm this. The RV measured by us on two epochs is consistent with that of TYC 8128-1946-1; the trigonometric distance of HIP 36312 is compatible with the photometric and kinematic ones for TYC 8128-1946-1. The star was not detected in X-ray but it is moderately active and lithium-rich. Taking these indicators' reduced age sensitivity for F stars into account, we consider the age to be compatible with that of TYC 8128-1946-1. Therefore, we classified the two objects as physically associated, adopting the trigonometric distance of HIP 36312 for TYC 8128-1946-1. We also added HIP 36312 to the list of probable members of the Argus association.

HIP 36414 = HD 59704 (ASAS 072931-3807.4) Proposed as a member of Carina-Near moving group by Zuckerman et al. (2006). However, the target's kinematics do not match the Carina-Near group at the <2.0 sigma level. On the other hand, the age of the star is consistent with 200 Myr or older. According to Tokovinin (2011) and Nordström et al. (2004), the star is an SB without an orbital solution ($\sigma_{RV}$ = 1.2 km s⁻¹). Our somewhat discrepant FEROS RV ($\Delta RV$ = 2.6 km s⁻¹ with respect to Nordström et al. 2004) further supports the presence of RV variability. We therefore classify this star as a likely SB, though additional measurements would be required for orbit determination. The system RV is also needed for a better assessment of MG membership. We also found non-periodic photometric variability. The star CCDM J07295-3807B at about 12 arcsec separation is not physically associated (Tokovinin 2011).

HIP 36948 = HD 61005 Proposed as a member of Argus by Desidera et al. (2011). At the <1.0 sigma level its kinematics match only the Argus association. The ages derived for this star are all ~100 Myr, slightly older than the ~40 yr age of the group but compatible with the Argus membership assignment. Malo et al. (2013) also propose this star as a bona fide member of Argus and this is further supported by the Gagné et al. (2014) online tool. In the Spitzer FEPS sample, this star exhibited the largest 24 µm excess with respect to the photosphere (Meyer et al. 2008). The star's disk was first resolved with HST (Hines et al. 2007), indicating the presence of two components: an external one shaped by interaction with the interstellar medium and an internal ring or disk. Observations in the H-band performed as part of our NaCo-LP (Buenzli et al. 2010) enabled the characterization of the inner ring, showing a significant offset of its center with respect to the star and also showing a rather sharp inner rim. These properties might be due to the perturbation by a planetary companion, undetected in the available observations.

HIP 37563 = HD 62850 Proposed as a member of Carina-Near moving group by Zuckerman et al. (2006). The target's kinematics match the Carina-Near group at the <1.0 sigma level and show no indication of matching any other group. Thus, the Zuckerman et al. membership assignment is confirmed. Our Lomb-Scargle and Clean analyses of the ASAS (ASAS 074236-5917.8) timeseries revealed two periods, P = 3.65 d and P = 1.37 d, in seven out of eight seasons and in the complete series. Considering the v sin i = 14 km s⁻¹ and the stellar radius R = 1.055 R☉, we infer rotation axis inclination values of i = 75° and i = 21°, respectively. An observed maximum light curve amplitude never exceeding ΔV = 0.02 mag is observed. The photometric amplitude and longer period are fully compatible with the activity level and age of the star. The shorter period would make the star an outlier in Fig. 6, 7. We therefore adopt P = 3.65 d as the rotation period.

HIP 37923 = HD 63608 Together with its wide (23.1 arcsec projected separation) companion HIP 37918 = HD 63581, HIP 37923 was proposed as a member of the Carina-Near moving group by Zuckerman et al. (2006) and as a member of the IC 2391 cluster by Nakajima & Morino (2012). The target's kinematics match the Carina-Near group at the <1.0 sigma level in V and W velocities but match at 3.2 sigma in the U velocity; HIP 37918 matches at 2.1 sigma in the U velocity. However, the age of the components is consistent with that of the Carina-Near group. The kinematics do not match well with IC 2391. Thus, the membership assignment to Carina-Near is still likely, although not as robust as other proposed members. The difference in Li EW between the components is striking, considering the small difference in temperature.

TYC 8927-3620-1 = HD 77307 (ASAS 085849-6115.3) Fast-rotating star with large lithium abundance, indicating a young age of about 20 Myr. The star was resolved as a very close visual binary (sep 0.1 arcsec) in NaCo-LP (ΔH = 0.50 mag) with an additional bright star at 4.9 arcsec. The latter (2MASS 08584794-6115161 = WDS 08588-6115B) is also included in 2MASS and WDS catalogs, being only 0.5 mag fainter than the central star. There is also an additional object (2MASS 08584777-6115335 = WDS 08588-6115C) listed in WDS at 19 arcsec. It has a different proper motion from TYC 8927-3620-1 in the UCAC4 catalog and, therefore, is not physically associated. A subgiant
luminosity class is reported in SACY. The target's kinematics are only consistent with the young, nearby population. Using both period search methods, we find $P = 0.874$ d in all ASAS seasons. The same period is also found by Bernhard & Bernhard (2010) and Kiraga (2012) from ASAS data.

HIP 46634 = HD 82159B (ASAS 093035+1036.0) Member of a wide pair whose components have similar brightness ($\Delta V = 0.01$ mag). We could not identify the rotation period, as the most significant frequency changed from season to season. No significant period comes out from the HIPPARCOS data analysis. Strassmeier et al. (2012) classified it as a single star based on extensive RV monitoring. Nordström et al. (2004) instead flagged it as being RV variable (rms RV 36 km s⁻¹, *N* = 2). Taking also the measured $v \sin i$ into account, we speculate that the spectroscopic measurements of the two components were exchanged in Nordström et al. (2004). The companion, HIP 46637 = GS Leo = HD 82159A, is a close SB (period = 3.86 days Strassmeier et al. 2012). Strassmeier et al. (2012) report a HIP 46637 rotation period of 3.05 days. Its age indicators, along with the integrated X-ray luminosity, are altered by the fast rotation induced by the close companion. These indicators are therefore not considered for age dating of the system. We note the large difference in lithium EWs in spite of the very similar temperatures of the stars. The lithium EW of HIP 46634 and $\log R_{HK}$ (the latter kindly provided by the SOPHIE Consortium) indicate an age intermediate between that of the Pleiades and Hyades. At the <2.0 sigma level, the kinematics do not match any of the investigated groups and associations. Its kinematics are similar to that of the Hyades. However, the solar metallicity derived by Strassmeier et al. (2012) argues against a physical link with this cluster. The G5 spectral type of HIP 46634 corresponds to an effective temperature warmer than 400 K than the photometric one. As the spectroscopic temperature by Strassmeier et al. (2012) is slightly cooler than the photometric one, we argue that the spectral classification needs to be revised.

HIP 47646 = HD 84199 (ASAS 094251–2257.9; 1SWASP+J094250.81-225755.7) is an F5V star that exhibits non-periodic photometric variability. A low level of chromospheric activity and low lithium content are derived from our FEROS spectra ($\log R_{HK} = -4.83$). The kinematic parameters are distant from the loci of investigated groups and associations. This is consistent with a moderately old age. Taking isochrone fitting and Casagrande et al. (2011) metallicity into account yields an age of $1.156 \pm 0.950$ Gyr. However, the star exhibits common proper motion and astrometric agreement with the K2.5 star HIP 47645 (projected separation of about 1200 AU), which appears to be much younger, based on high chromospheric activity (Gray et al. 2006). The system's integrated X-ray emission ($\log L_X = 29.25$) also supports the younger age. One way to reconcile all these observations would be to conclude that HIP 47645 is a tidally-locked SB, but no existing spectroscopic data confirms this hypothesis.

TWA 21 = HD 298936 Formerly listed by Song et al. (2003) as a candidate member of TWA and classified by Zuckerman & Song (2004) and Mamajek (2005) as a member, it was later rejected as a TWA member by Torres et al. (2008), based on the separation in the Z direction with respect to confirmed members. Viana Almeida et al. (2009) included it as a possible member of the Carina association (age 30 Myr). Our kinematic analysis, which includes the trigonometric parallax recently measured by Weinberger et al. (2013), shows

that this star is consistent with both the TWA and Columba groups at the <2.0 sigma level. The match to Columba in UVW space is actually within 1.0 sigma. The Malo et al. (2013) Bayesian analysis tools predict a 99% probability of Columba membership and only 1% probability of TWA membership. On the other hand, BANYAN II web tool yields a very high membership probability to Carina MG. In contrast to these results, Weinberger et al. (2013) recently showed, using a kinematic trace-back study, that the kinematics of TWA 21 are consistent with the TWA group. The age from isochrone fitting is intermediate between the quoted ages for TWA and Columba. The most probable lithium age is around 15–20 Myr with the sequence of Carina, Columba, and Tucana representing an upper limit. Independently from any membership assignment, we adopt the isochrone age of 17 Myr. Messina et al. (2010) found a rotation period $P = 4.43$ d in ASAS data.

TYC 7188-575-1 (ASAS 102204–3233.4; 1SWASP+J102204.47-323326.9) The star is an SB with a peak-to-valley RV difference of 83 km s⁻¹. The four available RV measurements are spread out over year timeframes and do not allow an estimate of orbital period, which might conclude the possibility of a tidally-locked system. Our FEROS spectrum reveals a complex CCF profile, suggesting a possible SB2 system. However, the comparison with CORALIE spectra shows that the spectral lines have comparable width, while moving tens of km s⁻¹ with respect to the FEROS spectrum. Therefore, the system may be triple or, more likely, the spectral lines are deformed by the presence of starspots, given the exceptionally high activity level (Balmer lines down to $H\epsilon$ were seen in emission). The star has the largest photometric variability (0.28 mag) in our sample. The X-ray emission is also very strong. The Lomb-Scargle and Clean analysis of ASAS and SuperWASP data reveal three major periodicities: $P = 4.27$ d, $P = 1.297$ d, and $P = 0.81$ d, in order of decreasing power. The longest period is listed in ACVS. However, it is not consistent with the $v \sin i = 25$ km s⁻¹ and the stellar radius of a K0V star. Therefore, we adopt $P = 1.297$ d as the rotation period. The extremely high activity level might be due to the interaction between the two stellar components, especially if they have already left the main sequence (RS CVn-type variability). The presence of lithium (comparable to that of Pleiades stars of similar spectral type) would also be consistent with an RS CVn system, as these stars often show a moderate lithium content (Pallavicini et al. 1992), although of still debated origin. Adopting the mean RV from the available measurement and using the photometric distance, assuming a main sequence star, yield kinematic parameters that are compatible with the nearby, young population. However, the center of mass RV is needed for a better assessment.

TYC 6069-1214-1 = BD-19 3018 (ASAS 102737–2027.2; 1SWASP+J102737.33-202710.6) Only SACY spectroscopic data available. The most important photometric period is $P = 3.91$ d ($P = 4.14$ d in SuperWASP data). There also exists a second period, $P = 1.34$ d, in both ASAS and SuperWASP data, as reported by Kiraga (2012). However, the absence of known $v \sin i$ prevents us from distinguishing between the correct one and the alias. At <2.0 sigma, the target's kinematics match only the Carina association. The star's age from multiple youth indicators is intermediate between that of Carina association and of AB Dor MG, making the Carina membership unlikely.
TYC 7722-0207-1 = HD 296790 (ASAS 102204–3233.4; 1SWASP+J103243.90-444055.6) Classified as a possible TWA member by Reid (2003), but our analysis of kinematics and age indicators does not support it. The Lomb-Scargle and Clean analysis of the photometric time series reveal two periods, *P* = 2.01 d and *P* = 1.975 d, of comparable power in almost all seasons. Both may be real, arising from surface differential rotation. These periods are also consistent with the *v sin i* = 27.2 km s⁻¹. A period *P* = 4.29 d is listed in ACVS and reported by Kiraga (2012). Such a value is not consistent with *v sin i* and the stellar radius.

TYC 7743-1091-1 = HD 99409: (ASAS 112558–4015.8; 1SWASP+J112558.28-401549.9) This is a late type star with a moderately strong lithium line, as measured by Wichmann et al. (2003); Weise et al. (2010). Luminosity class II-III is quoted in the Michigan Spectral Survey Catalog (Houk 1982). DDO photometry by Norris (1987) also supports luminosity class III and excludes a dwarf star. Our analysis of a FEROS archive spectrum confirms the giant status of the star. We derived *T*<sub>eff</sub> = 4931 ± 59 using ARES. From this, we concluded log*n*(Li) ~ 1.9 dex. The most important photometric period is *P* = 39 ± 7 d, based on both our methods of period search. The star is found to be a hard X-ray source (HR1 = 0.86 ± 0.08). The RVs from Wichmann et al. (2003) and the FEROS spectrum differ by 4.3 km s⁻¹, making it a suspected SB. HD 99409 is therefore not a bona fide young star but should be rather added to the census of lithium-rich giants. The moderately large *v sin i* (17 km s⁻¹), fast rotation (39 days), and strong X-ray emission are remarkable for a giant star. Similar features have been reported for other lithium-rich giants, and, indeed, the frequency of lithium-rich stars is much larger for fast-rotating giants than for normal giants (Drake et al. 2002). These features might be linked to planet engulfment phenomena (Siess & Livio 1999; Carlberg et al. 2010, 2012), but alternative mechanisms have also been proposed (de la Reza & Drake 2012). The kinematic parameters are inconsistent with all of the groups investigated.

HIP 58240 = HD 103742 (ASAS 115642–3216.1; 1SWASP+J115642.30-321605.3) With its wide companion HIP 58241 = HD 103743 (ASAS 115644–3216.0; 1SWASP+J115643.77-321602.7), HIP 58240 was proposed by Zuckerman et al. (2006) to be a member of the Carina-Near moving group. The kinematics of HIP 58240 match the TWA, Argus, and Carina-Near moving group at the <2.0 sigma level. The age diagnostics measured for this target are inconsistent with the expected ages for the TWA and Argus associations. The kinematics of HIP 58241 match Argus, the Carina-Near moving group, the Hercules-Lyra association, and IC 2391 at the <2.0 sigma level. Considering both components and the age diagnostics, the membership to Carina-Near is likely. For both stars, we could derive the rotation period in neither ASAS nor SuperWASP data; each season showed its own significant periodicity. This may be linked to the blending of the components in ASAS and SuperWASP images. HIP 58241 is a nearly perfect Solar analog (except for multiplicity) at an age of 200 Myr (D’Orazi et al. 2012). This component was not observed in the NaCo-LP, Tokovinin et al. (2010) and Tokovinin (2011) identified an additional source at about 4 arcsec from HIP 52841. Its physical association to HIP 52841 requires confirmation. WDS lists an additional component, CD-31 9365 C, which is an unrelated F2 background star (Torres et al. 2006).

TYC 9231-1566-1 = HD 105923 (ASAS 121138–7110.6) New close visual binary (Δ*H* = 3.02 mag at 1.98 arcsec). It was proposed by Torres et al. (2008) as an 80% probability member of the *ε* Cha association with a kinematic distance of 115 pc and by Mamajek et al. (2002) as a high probability member of LCC with a kinematic distance of 98.5 pc. Mamajek et al. (2002) estimated *A*<sub>V</sub> = 0.48 ± 0.08, while Messina et al. (2011) derived a significantly lower value (E(B − V) = 0.03, *A*<sub>V</sub> = 0.1). This discrepancy originates from the two different spectral classifications in Mamajek et al. (2002) and Torres et al. (2006; G3IV vs. G8V respectively). Our spectroscopic effective temperature (5530 ± 40 K) supports an intermediate value, E(B − V) = 0.08. Adopting this latter value, we infer a photometric distance of 98 pc for an age of 10 Myr. The age indicators clearly point to a very young age, consistent with those of *ε* Cha and LCC. An age younger than *β* Pic MG is likely, thus favoring the *ε* Cha membership. However, considering the uncertainty in the distance and reddening, and the influence of the newly discovered binary companion, we consider 20 Myr to be an upper limit for the stellar age. Messina et al. (2011) report a rotation period of *P* = 5.05 d, which they classified as “confirmed”. This was subsequently also confirmed by Kiraga (2012). The star has no significant RV variations.

TYC 8979-1683-1 = CD-62 657 (ASAS 122825–6321.0): Classified as an LCC member by Song et al. (2012) with a photometric distance of 73 pc. We derived a similar photometric distance of 75.6 pc, assuming no reddening. However, the discrepancy between the photometric (5306 K) and the spectroscopic (5650 ± 145 K) effective temperature, along with the spectral type (G7V), may indicate the presence of some amount of interstellar or circumstellar absorption (E(B − V) ≤ 0.10 mag). This may increase the distance estimate up to about 80 pc, and would imply an even younger age from Li EW. Our analysis indicates that the target’s kinematics match TWA, US, and Corana Australis at <2.0 sigma. The star’s age from multiple youth indicators is also consistent with these young ages. The target’s declination is further south than any known member of TWA, implying that a membership is unlikely. The star may belong to the outskirts of UCL or LCC, in the direction of the Sun, having a photometric distance, which is closer to the mean distances of the ScoCen subgroups. The most important period in the photometric time series is *P* = 3.35 d, which is the same as the one found by Kiraga (2012). However, it is inconsistent with *v sin i* = 31.9 km s⁻¹ and the stellar radius. Using both period search methods, we also find two other important periods of comparable power: *P* = 1.42 d and *P* = 0.76 d in all the seasons and in the complete series. Considering the stellar radius *R* = 1.035 *R*<sub>☉</sub>, we infer rotation axis inclination values of *i* = 60° and *i* = 37°, respectively. An observed maximum light curve amplitude up to Δ*V* = 0.11 mag is observed, suggesting that the star’s rotation period is likely *P* = 1.42 d.

TYC 8989-0583-1 = HD 112245 (ASAS 125609–6127.4) New close visual binary discovered in our program (Δ*H* = 2.6 mag). Classified as an LCC member in Song et al. (2012) with a photometric distance of 68 pc (close to our adopted value of 65 pc). The target’s kinematics match Tuc/Hor, TWA, and UCL at <2.0 sigma. The star’s age from multiple youth indicators is consistent with it being very young and compatible with the ages of Tuc/Hor but likely is younger. The target’s declination is further south than any known member of TWA, implying that it is likely not a member
of this association. The target's photometric distance is also
only half of the distance expected for membership in one of
the ScoCen subgroups. However, it could be part of the pop-
ulation of closer stars linked to these groups, as studied by
Song et al. (2012). We do not have spectra for the derivation
of spectroscopic temperature. From spectral type (K0Ve) and
photometric temperature (4929 K), a small amount of ab-
sorption can not be excluded. The Lomb-Scargle analysis of
the photometric timeseries indicated P = 4.89 d, P = 1.25 d,
and P = 0.83 d as the most important periods. However, the
two longer ones are inconsistent with v sin i = 47 km s⁻¹ and
the stellar radius R = 1.095 R☉. The Clean analysis shows
P = 1.25 d and P = 0.556 d to be the most important. We
adopt P = 0.556 d as the rotation period, which is also re-
ported by Bernhard & Bernhard (2010).

TYC 9245-0617-1 = CD-69 1055 (ASAS 125826-7028.8) The star is a WTTS, as indicated by its strong lithium, filled-in Hα line, strong X-ray emission, and near-IR excess. Torres et al. (2008) proposed it as an 80% probability member of the ϵ Cha association, while Mamajek et al. (2002) and Song et al. (2012) proposed it to be a member of LCC. Kinematic distances of 101 pc and 85 pc were derived by Torres et al. (2008) and Mamajek et al. (2002), respectively, while Song et al. (2012) obtained a photometric distance of 75 pc. Mamajek et al. (2002) estimated A<sub>V</sub> = 0.46 ± 0.12 while Messina et al. (2011) derived a slightly lower value (E(B−V) = 0.11, A<sub>V</sub> = 0.34). Our spectroscopic and photometric temperatures are equal for E(B−V) = 0.09. Adopting this latter value, we infer a photometric distance of 93 pc for an age of 10 Myr, which is supported by the Li EW of 410 mÅ. This is consistent with the Torres et al. (2008) kinematic estimate, and together with our kinematic analysis for this distance it supports the association with ϵ Cha. Messina et al. (2011) and Kiraga (2012) report a rotation period of P = 2.007 and P = 1.989 d, respectively. From the RV data, there is an indication of RV variability on timescales of a few years and amplitude of a few km s⁻¹. Considering the young age and the probable presence of circumstellar material, this might be due to variable obscuration from the circumstellar disk (see, e.g., Schisano et al. 2009, for the case of T Cha) and the presence of a companion. We, therefore, consider the star as a possible SB, but we keep it in the sample for the statistical analysis.

HIP 63862 = HD 113553 (ASAS 130517-5051.4) This target's kinematics do not match any of the groups and associations investigated at the <2.0 sigma level. Its kinematics are also not consistent with the nearby, young population. The star is estimated to be slightly older than 100 Myr. The most important period is *P* = 4.5 d, which is found in almost all seasons and confirms the period *P* = 4.456 d found by Kiraga (2012).

TYC 7796-2110-1 = CD-41 7947 (ASAS 133432-4209.5; 1SWASP+J133431.89-420930.7) was reported as a suspected SB2 in the SACY survey. The photospheric lines appear very broad in our FEROS spectrum; the target might be indeed an unresolved SB2 with fast-rotating (and very active) components. The CORALIE spectrum also shows a complex profile, but we can not confirm the SB2 status from these data (similar line width). Three-epoch RVs show large scatter; however considering the large measurement errors, this is not conclusive for a binary classification. The star was classified as an LCC member in Song et al. (2012) with a photometric distance of 93 pc, which is very similar to our adopted value of 92 pc. The rotation period *P* = 1.022 d is found in both ASAS and SuperWASP data by both period

search methods. The target's kinematics and age are consis-
tent with the young, nearby population at the <2 sigma level,
and with UCL and LCC at the <3 sigma level. We noted a
large difference in Li EW between SACY and Song et al.
(2012) (400 vs. 315 mÅ, respectively). Age indicators are
consistent with LCC, but the very fast rotation and possible
binarity make the parameters uncertain.

TYC 9010-1272-1 = HD 124831 (ASAS 141805-6219.0) New close visual binary (projected separation 0.27 arcsec = 25 AU, ΔH = 1.01 mag). The star is also listed as a possible SB2 in SACY. The analysis of our FEROS spectrum shows a strongly asymmetric CCF, which is likely due to an additional component. Significant RV variations are reported in the literature. Considering the RV difference between the components, ~20 km s⁻¹ in our FEROS spectrum, and the line depth ratio of about 0.7, it is plausible that the newly discovered visual companion is not the main object responsible for the RV variations and spectral contamination. The system might therefore be triple. The period *P* = 1.477 d is the most important period found by either Lomb-Scargle or Clean analysis. This confirms the earlier determination by Kiraga (2012) and is consistent with *v sin i* = 38 km s⁻¹ and the stellar radius. The target kinematics match several groups subgroups at the <2.0 sigma level. Considering the star age, membership to Tuc/Hor or COL, seems plausible, but improved understanding of the multiplicity and of the system RV are needed.

HIP 70351 = HD 125485: (ASAS 142339-7248.5) Young star with an age of about 100 Myr, consistently derived from various indicators. The most important period in the photometric time series is *P* = 3.58 d, but the period *P* = 1.385 d is also present in both Lomb-Scargle and Clean periodograms. No period is found from HIPPARCOS data. The target's kinematics do not match any of the groups and associations investigated at the <2.0 sigma level. Its kinematics are also not consistent with the nearby, young population.

HIP 71908 = GJ 560A = α Cir (ASAS 144230-6458.5) roAp star. Isochrone fitting, carried out using the effective temperature by Bruntt et al. (2008), yields an age of 1.10 ± 0.17 Gyr. Bruntt et al. (2009) report a rotation period *P* = 4.479 d for the primary. No period is derived from ASAS nor from HIPPARCOS data. The wide companion GJ 560B = SAO 252852 is included by López-Santiago et al. (2006) in the list of Her-Lyr members. HIP 71908 is also proposed by Nakajima & Morino (2012) as a member of β Pic MG. The kinematics of the star are consistent with the ϵ Cha moving group and Her-Lyr association at the <1.0 sigma level. BANYAN II web tool yields a very high membership probability to β Pic MG. However, the age measured by comparing isochrones in the HR diagram indicates that the primary has an age around 1 Gyr, making it much older than either of these groups. There are also no indications of young age for the secondary, as the system is not detected with ROSAT; the level of chromospheric activity is low and lithium is not detected in the spectrum. These age estimates rule out kinematic membership in either of these young associations, and the star is therefore likely an older field dwarf interloping in the kinematic space where young stars are concentrated. We adopt the isochrone age of the primary.

HIP 71933 = HD 129181 (ASAS 144244-4848.0) RV measurements from SACY, Nordström et al. (2004), Waite et al. (2011) and our FEROS spectrum show a rather large scatter (4 km s⁻¹), suggesting binarity. Indication of binarity comes also from the astrometric acceleration detected by
HIPPARCOS. The small $v \sin i$ quoted by Nordström et al. (2004) (2 km s⁻¹) is highly discrepant with the fast rotation reported by Waite et al. (2011) and with our own spectrum (70 km s⁻¹). The Nordström et al. (2004) RV measurement should therefore be taken with caution. The broad photospheric lines make the RV measurement rather uncertain, and an SB2 nature cannot be ruled out. However, the deformation of the line profile might also be due to spots. This issue was also discussed by Waite et al. (2011), who favor the star-spot interpretation. We therefore consider this star as only a possible binary. Our analysis of photometric data reveals marginal evidence of a period P = 0.67 d in two ASAS seasons and in the HIPPARCOS data. This star is very active and is also found to be a relatively hard X-ray source (HR1 = 0.58 ± 0.07). The strong lithium EW is consistent with an age between about 30 and 150 Myr. The star is clearly above the main sequence on the color-magnitude diagram with an isochrone age of 16 ± 6 Myr. This is marginally inconsistent with the Li estimate, but the fast rotation makes the Li EW measurement uncertain. The kinematics are fully consistent with UCL when Tycho2 proper motion is adopted (1.9 sigma discrepancy with respect to VL07) and Nordström et al. (2004) RV is excluded. Isochrone age is also fully compatible with UCL but the distance is closer than that of most of its known members. We therefore conclude that this is a truly young star located in front of UCL. It is uncertain whether it is physically related to UCL and/or LCC. It may be a binary with a period of a few years, but this needs confirmation.

HIP 72399 = HD 130260 (ASAS 144810–3647.0; 1SWASP+J144809.66-364702.2) This is a very active K dwarf but without detectable lithium. Four RV determinations (one by SACY and the others ours from HARPS and CORALIE data) show that the star is an SB1. The two CORALIE spectra were taken with a time separation of about one hour and have an RV difference of about 3 km s⁻¹, indicating a short period for the binary orbit. Our analysis of ASAS data confirms the P = 3.897 d period reported by Kiraga (2012). We find the same period in the SuperWASP data as well. The K5V star HIP 72400 = HD130260B at 10 arcsec is a probable wide companion. It has similar proper motion and parallax, but a slightly different RV (which can be understood as being due to our poor sampling of the HIP 72399 binary orbit). Both components have rather large parallax errors. The X-ray emission of the two components is not spatially resolved by ROSAT, but the XMM source reported in Saxton et al. (2008) is much closer to the SB component, suggesting that it is the main X-ray emitter. The lack of lithium in the primary yields an age lower limit of about 300 Myr, which is not consistent with the estimates based on coronal and chromospheric emission and rotation period. The kinematics of HIP 72400 are slightly outside the box of very young stars but fully compatible with a moderately young age. Its slow rotation, as derived from the CORALIE spectrum, argues against a star as active as the primary. All these facts support the hypothesis that the high activity and fast rotation of HIP 72399 is due to tidal locking and not to a young age. However, we can not conclusively demonstrate this without a measurement of the binary's orbital period.

TYC 7835-2569-1 = HD 137059 (ASAS 152517–3845.4; 1SWASP+J152516.99-384526.0) Close visual binary (1.05 arcsec separation, $\Delta V$ = 0.3 mag, $\Delta H$ = 0.1 mag) first discovered by Brandner et al. (1996) and confirmed by NaCo-LP data. The star was found to be SB2 from CORAVEL spectra. Makarov (2007) classified it as a

member of the Lupus association (age 5–27 Myr) with a kinematic distance of 89 pc, but the star is not included in the recent study of the Lupus star-forming region by Galli et al. (2013). Kinematic parameters are consistent with $\beta$ Pic, Cha-Near, CrA and Upper Sco. However, the unresolved binary may imply that the RV measurements used in these analyses are very uncertain, making the kinematic analysis difficult to interpret. Furthermore, lithium EW and X-ray flux are below those of most members of the youngest associations, such as $\beta$ Pic and Tuc-Hor. Rather, the fluxes are more compatible with an age older than those quoted in Makarov (2007) for Lupus and the ages of other groups mentioned above. The star is therefore most likely a moderately young star without associations to known groups. Our kinematic distance, using the AB Dor MG sequence as a reference, and including binary correction, is 70.2 pc. The SuperWASP data analysis gives a period P = 3.69 d. In contrast, the ASAS data analysis gives two periods, P = 2.32 d and P = 1.75 d. Considering the stellar radius $R = 1.009 R_\odot$ and $v \sin i = 17$ km s⁻¹, we infer rotation axis inclination values of i = 50° and i = 36°, respectively. The observed maximum light curve amplitude never exceeds $\Delta V$ = 0.04 mag, suggesting that both rotation periods are possible. The present data do not allow us to be sure about the correct rotation period. The multiple photometric periods might belong to the different components, considering their similar brightnesses.

HIP 76829 = HD 139664 (ASAS 154111–4439.7) Proposed as a member of the Her-Lyra association by López-Santiago et al. (2006). The kinematics of the star are consistent with Her-Lyr at the <2.0 sigma level. Beside kinematics, additional indications of youth are provided by coronal and chromospheric emission and fast rotation, but the sensitivity of these diagnostics for mid-F stars is not so strong. No lithium was detected in our analysis of the HARPS spectra. The age of the star resulting from X-ray and Ca H and K is compatible with Her-Lyr membership. We find marginal evidence of a period P = 0.719 d, which is consistent with $v \sin i$ = 71.6 km s⁻¹ and the stellar radius. However, the measured period is very uncertain. HIP 76829 hosts a debris disk, which was spatially resolved by Kalas et al. (2006) using HST. The disk is oriented nearly edge-on. The emitting material is concentrated on a belt at a separation of about 83 AU.

TYC 6781-0415-1 = CD-24 12231 (ASAS 154131–2520.6; 1SWASP+J154131.21-252036.4) Very young star with a lithium age younger than 10 Myr (from B-V color). Classified by Aarnio et al. (2008) as a probable member of US with a kinematic distance of 109 ± 11 pc. This star is found to be a hard X-ray (HR1 = 0.94 ± 0.03; see Sect. 6.2) and radio (Martí et al. 2004) source. This is consistent with the very young age of US and the age derived from the lithium EW of the star. Martí et al. (2004) quotes the star as RV constant over four consecutive nights but does not provide RV values. Individual RVs from SACY and Aarnio et al. (2008) are also consistent with a single star. We note a highly discrepant effective temperature from B-V and V-K colors (5373 K vs. 4569 K); reddening cannot account for this. The temperature from B-V is consistent with the G9IVe and G8e spectral classifications from SACY and Carpenter et al. (2009) respectively. The high level of activity implies high levels of photometric variability. This would result in significant errors when combining magnitudes taken several years apart. However, from ASAS data, the variability in V band
over 10 years is within 0.18 mag, and thus unable to explain the discrepancy. Alternatively, significant *K* band excess could be due to a circumstellar disk. Using only the *B*–*V* color, since it is consistent with the spectral classification, we derive a photometric distance of 89 pc using the β Pic sequence (upper limit). We derive 106 pc for a 11 Myr age. Within the uncertainties, these distances are compatible with the kinematic distance by Aarnio et al. (2008). The kinematic analysis made with the longer distance supports the association with US. The ASAS data analysis gives two likely periods, *P* = 1.05 d and *P* = 20 d, whereas the SuperWASP data analysis gives a period *P* = 1.05 d as the most significant, although periods of 20d and longer are also present. The rotation period *P* = 1.05 d is compatible with the stellar radius and *v sin i*. The rotation period *P* = 1.05 d is “uncertain”.

TYC 6786-811-1 = HD 140722C (ASAS 154611-2804.4; 1SWASP+J154610.73-280423.3) The star was first resolved into a close visual binary (0.11 arcsec separation) by Köhler et al. (2000). The companion was also detected in our NaCo observations. This star is classified as a US-B (which corresponds to UCL) member (Köhler et al. 2000; Kraus & Hillenbrand 2007). No significant period is found either in ASAS or in SuperWASP photometric data. The tight triple system HIP 77235 = HD 140722 = HR 5856 at 50 arcsec has similar proper motion and radial velocity. The discrepancy, slightly exceeding the quoted errors, may be due to the multiplicity of both the wide components. HIP 77235 is a close triple. AB components have a separation of 0.58 arcsec with A further resolved into a closer pair with 0.20 arcsec projected separation. The integrated spectral type of the triple is F2IV. The trigonometric distance of HIP 77235 is 71.1 ± 5.5 pc, compatible with the photometric distance of TYC 6786-811-1 (which is 78.6 pc including the correction for binarity), and further supporting the physical association. However, the literature contains no indications of youth for the tight triple, and it was not detected in X ray by ROSAT. This may be due to the early spectral type of the components, which should all be F stars based on the magnitude differences with respect to the primary. In the end, we consider this target to be inconclusive. Age indicators (Li and X-ray emission) for HD 140722C support a young age (nominal ages of 60 Myr for Li and 120 Myr for X-ray), but not as young as the UCL age (16 Myr). The derived distance also seems to argue against a membership with the UCL group. Using the HIPPARCOS distance of the wide companion, the UVW velocities of the star is not consistent with any group, within 2.0 sigma. Thus, our kinematic and age analysis make UCL membership unlikely. The star might be an outlier in the kinematic distribution of most nearby young stars. However, an unresolved binarity could make the adopted RV measurements uncertain.

HIP 78747 = HD 143928 = HR 5975 (ASAS 160437-3751.8) Mid F star, originally classified by Gray et al. (2006) as young because of the high log $R_{HK}$. But much lower activity levels are reported in Schröder et al. (2009) and also measured in our FEROS spectrum. The star was also not detected by ROSAT. The isochrone age is 2.357 ± 0.627 Gyr, taking the subsolar metallicity by Casagrande et al. (2011) into account. No period is found either in ASAS or HIPPARCOS data. The target is likely an old star, but with young star kinematics. The companion listed in WDS and CCDM (CD-37 10680B, *V* = 13.0 at about 40 arcsec) is not physically associated.

TYC 6209-0769-1 = BD-19 4341 (ASAS 161414-1939.6) Moderately young star with an age similar to the Pleiades. We find two periods of comparable powers, *P* = 2.14 d and *P* = 1.86 d, using both a Lomb-Scargle and Clean analysis of the ASAS timeseries. The rotation period *P* = 2.14 d is “likely”. The target’s kinematics are consistent with the young, nearby population.

HIP 79958 = HD 146464 (ASAS 161916-5530.3) This is a moderately young star with an age similar to the Pleiades. The period *P* = 2.325 d that we find with both Lomb-Scargle and Clean was also reported by Koen & Eyer (2002) from HIPPARCOS data and by Kiraga (2012) from ASAS data. The rotation period derived from log $R_{HK}$ is much longer than the observed one (Fig. 7). As there are no additional plausible longer period periodicities in the photometric time-series, the discrepancy is likely due to one of the following: (1) the chance observation of low-activity phases on the 3-epoch CORALIE monitoring; or (2) errors in the transformation from *S* Index to log $R_{HK}$, as the color of the star is slightly outside the validity range of the Noyes et al. (1984) prescriptions. At the <2.0 sigma level, the target’s kinematics and age are only consistent with the nearby, young population.

HIP 80290 = HD 147491 = V972 Sco (ASAS 162323-2622.3; 1SWASP+J162322.93-262216.3) Close visual binary observed with NACO (projected separation 3.3 arcsec; $\Delta H$ = 1.9 mag). A source at similar position close to the star is reported in the 2MASS catalog (2MASS 16232272-2622168) but with a magnitude much brighter than our measurement. Yao & Tong (1989) classified it as a $\delta$ Scu variable. This classification was revised by Handler (1995); we confirm it is a BY Dra rotational variable. We find a period *P* = 1.513 d among ASAS, SuperWASP, and HIPPARCOS data, which agrees with the earlier determination by Kiraga (2012). The star is projected close to the globular cluster M4. The star’s kinematics match Corona-Australis at the <2.0 sigma level. The estimated age of the star is quite young and it may have membership consistent with CrA. The star is also kinematically equivalent with the nearby, young population. The star WDS J16234-2622B = 2MASS J16232242-2622230 at a projected separation of about 10 arcsec is likely not physically associated.

HIP 80758 = HD 148440 (ASAS 162920-3057.7; 1SWASP+J162920.16-305739.8) The young age (adopted value of 20 Myr) is derived consistently from various indicators, including isochrone fitting (19 ± 14 Myr). The target’s kinematics is only consistent with the young, nearby population. We find *P* = 3.38 d from ASAS data and *P* = 3.55 d from SuperWASP data. No period is derived from HIPPARCOS data.

TYC 6818-1336-1 = HD 153439 (ASAS 170043-2725.3) This star was classified as a possible member of the Upper Scorpius association (Aarnio et al. 2008), with a kinematic distance of 130 ± 12 pc. There is a severe discrepancy on the star’s spectral type: GOIV according to SACY and F5 according to the Michigan spectral atlas. The latter is adopted by Aarnio et al. (2008). This has a significant impact on the presence of reddening and, therefore, on the distance to the star. Considering the better agreement of photometric temperatures from *B*–*V* and *V*–*K* and the higher spectral resolution of SACY spectra, we adopt the unredened case. The age of the system is also quite uncertain. The star is found to be a relatively hard X-ray source (HR1 = 0.46 ± 0.20), which supports a very young age. Lithium EWs from SACY and Aarnio et al. (2008) differ
by 30 mÅ. Taking these uncertainties into account, ages from 10 to 100 Myr are possible. The most important photometric period is *P* = 1.13 d, which is found in only three seasons. The rotation period *P* = 1.13 d is “uncertain” and does not contribute meaningful age constraints. Adopting an age of 30 Myr, we derive a photometric distance of 89.5 pc. However, if the star is younger than 15 Myr, then the distance would be farther than 100 pc (105 pc using *β* Pic sequence). The star’s kinematics are only consistent with the young, nearby population and Corona-Australis association at the <2.0 sigma level.

TYC 6815-0874-1 = CD-25 11922 (ASAS 170433–2534.3) Fast-rotating star, flagged as a possible SB2 in SACY. There are two spectra from SACY; the line profile changed between the two epochs, but the line width is similar. We thus cannot claim conclusive inference that it is an SB2. From the ASAS photometric data, we find a period *P* = 1.373 d using both Lomb-Scargle and Clean analyses. In a comparison of spectral type vs. photometric effective temperature, there are indications of some amounts of reddening (*E*(*B* − *V*) ~ 0.1 mag). Taking the *β* Pic sequence as reference, we derive a distance of 109 pc. The possibility that the star is an SB2 adds uncertainty to the derivation of stellar properties from photometry. The target’s kinematics and age are only consistent with the young, nearby population. The star position is at the edges of the US group. The UVW velocities all match those of the US group but only at the <3.6 sigma level. The nominal position of the X-ray source RXS J170428.0-253520, which is classified in SACY as the X-ray counterpart of TYC 6815-0874-1, is 93 arcsec apart from that of the optical source, but with a very large position error (41 arcsec). We also noted that the integration time in the ROSAT catalog is significantly smaller than the usual ones. Furthermore, the X-ray source is hard (HR1 = 1.00 ± 0.32), which is unusual for the kind of stars we are investigating. Without additional X-ray observations, we are unable to conclude on the association of the ROSAT source with our target star.

TYC 6815-0084-1 = CD-25 11942 (ASAS 170601–2520.5) is also a fast-rotating suspected SB2 in SACY (no clear signature of binarity in our spectrum). TYC 6815-0084-1 is a possible member of Upper Scorpius association according to Aarnio et al. (2008) with a kinematic distance of 127 pc. Assuming a reddening *E*(*B* − *V*) = 0.08 from the comparison of spectral type and photometric temperatures and adopting as reference the sequence of *β* Pic MG, we obtain a photometric distance of 79 pc, which increases to 92 pc for a 11 Myr age. The lithium EW is compatible with a very young age (10–20 Myr) and then with US membership. The space velocities are also compatible with US, and matching improves increasing distance to 110–130 pc. The sky position is only 0.7 deg outside the formal boundaries of US adopted in Preibisch & Mamajek (2008). We find more photometric periods that persist in different seasons and that are all close or shorter than 1 day, which is expected from the high *v sin i* = 57 km s⁻¹. However, it is difficult to say which is the correct one. One likely period is *P* = 1.243 d, but also *P* = 1.03 d and *P* = 0.507 d may be the rotation periods. A very similar period (1.246d) is also listed in Kiraga (2012). The star has similar kinematic parameters to TYC 6815-0874-1, which is also in our sample. The projected separation of the two stars is about 21 arcmin, a value that is too large for a bound system (≥100 000 AU); however considering the similar ages, a common origin for the

two stars cannot be excluded. The photometric distances are roughly consistent taking the uncertainties due to reddening, age, and possible binarity of both objects into account.

TYC 7362-0724-1 = HD 156097 (ASAS 171658–3109.1) G5V star with large lithium content. Only one SACY measurement is available. We find a photometric period of *P* = 1.92 d. The star’s kinematics match Corona-Australis at the <2.0 sigma level. The estimated age of the star is quite young (about 20 Myr), and it could be consistent with CrA membership. The position on the sky is slightly outside the nominal edges of US and UCL; membership in the US or UCL groups can not be excluded.

TYC 8728-2262-1 = CD-54 7336 (ASAS 172955–5415.8) Proposed by Torres et al. (2008) as a 90% probability member of *β* Pic. At the <2.0 sigma level, its kinematics match *β* Pic, TWA, Chamaleon, and Corona Australis. The target’s position on the sky is inconsistent with the TWA known member distribution. Ages derived from various methods are fully compatible with *β* Pic MG. Thus, the analysis reinforces the *β* Pic membership assignment. The Malo et al. (2013) Bayesian analysis tools predict 100% probability of *β* Pic membership at a distance of 71.5 pc. This predicted distance for membership is consistent with the photometric distance of 70.4 pc. The Gagné et al. (2014) online tool yield only a 19% membership probability. Instead Song et al. (2012) classified the star as a US star with a photometric distance of 72 pc. Messina et al. (2010) and Kiraga (2012) report a rotation period *P* = 1.819 d. However, the secondary period *P* = 0.620 d that is also found in five out of nine seasons may be more consistent with *v sin i* = 35.3 km s⁻¹ and the stellar radius. The rotation period *P* = 0.620 d is “uncertain”.

HIP 86672 = HD 160682 = V2384 Oph (ASAS 174230–2844.9) Our analysis does not reveal evidence of eclipses, although Malkov et al. (2005) listed it in their catalog of eclipsing binaries. Malkov et al. (2005) neither give an orbital period nor find the secondary minimum, which makes their classification questionable. We derive the same period *P* = 3.755 d from either Lomb-Scargle or Clean analyses. This value is similar to the *P* = 3.912 d period found by Kiraga (2012) The star’s kinematics match Corona-Australis at the <2.0 sigma level. The estimated age of the star is young (30 Myr) but is marginally inconsistent with the CrA’s younger proposed age.

HIP 89829 = HD 168210 (ASAS 181952–2916.5) Ultrafast-rotating star (*v sin i* 114 km s⁻¹) that is proposed by Torres et al. (2008) and Malo et al. (2013) as a high-probability member of *β* Pic MG, while membership is rejected by BANYAN II. At the <2.0 sigma level, its kinematics match *β* Pic. The large lithium EW and high levels of activity and photometric variability are consistent with the *β* Pic MG membership assignment. Isochrone fitting further supports the pre-MS status (age of 15 ± 3 Myr). The star resides in a field that is very crowded with fainter stars. We derive the same period *P* = 0.571 d from either Lomb-Scargle or Clean analyses. This period is also reported by Kiraga (2012) and in ACVS. No period is found in the HIPPARCOS data. According to Waite et al. (2011), the star is likely single, with line profile variations most likely due to star spots.

HIP 93375 (ASAS 190106–2842.8) Proposed by Torres et al. (2008) as a high-probability member of AB Dor. The target’s age from various youth indicators is about 100 Myr, which agrees with the range expected for AB Dor members. Thus, the analysis reinforces the AB Dor membership assignment.
Malo et al. (2013) Bayesian analysis tools predict a 91% probability of AB Dor membership at a distance of 63.5 pc. This predicted distance for membership is consistent with the measured distance of 70.4 pc. On the other hand, the membership is formally rejected by the Gagné et al. (2014) online tool. We find no rotation period in either the ASAS data or the HIPPARCOS data. There is another star, WDS J19011-2843B = CD-28 15269B, at 11 arcsec projected separation. TYCHO2 and UCAC give no proper motion measurements for the possible secondary. However, the variations in projected separation, as listed in WDS (from 10.0 to 11.1 arcsec in 23 years), seem to argue against a physical association. When blinking images from different epochs, the candidate secondary also does not appear to exhibit co-movement with the primary.

HIP 94235 = HD 178085 (ASAS 191057-6016.0) New close visual binary ($\Delta H$ = 3.8 mag at 0.51 arcsec). Proposed by Torres et al. (2008) and Malo et al. (2013) as a bona fide member of AB Dor, while the Gagné et al. (2014) online tool yields a membership probability of 33%. At the <1.0 sigma level, its kinematics are only consistent with AB Dor. Age indicators are consistent with youth, reinforcing the AB Dor membership assignment. Messina et al. (2010) report a rotation period $P$ = 2.24 d, which is subsequently confirmed by Kiraga (2012). The most important periods derived from a HIPPARCOS photometric data analysis are $P$ = 4.28 d and $P$ = 2.38 d. Considering the $v \sin i$ = 24 km s⁻¹ and the stellar radius $R$ = 1.085 $R_⊙$, we infer that the only consistent period is $P$ = 2.24 d.

TYC 6893-1391-1 = CD-25 14224 (ASAS 193919-2539.0; 1SWASP+J193918.66-253901.3) Early K-dwarf for which age indicators yield an age slightly older than the Pleiades. Applying both Lomb-Scargle and Clean analyses to ASAS and SuperWASP data, we find a period $P$ = 7.49 d, which confirms the period determination by Kiraga (2012). The target's kinematics are only consistent with the young, nearby population.

TYC 5736-0649-1 = BD-14 5534 (ASAS 194536-1427.9) This star has extremely high $v \sin i$ for a G6V star (206 km s⁻¹). The only period consistent with $v \sin i$ and the stellar radius is $P$ = 0.2516 d. Kiraga (2012) reports a double period $P$ = 0.5077 d, which is too long for the measured $v \sin i$. The star is found to be a relatively hard X-ray source (HR1 = 0.61 ± 0.25). The target's kinematics and age are only consistent with the Corona Australis association. The star was flagged in SACY as a possible SB, having an RV rms of 3.5 km s⁻¹. However, the very large $v \sin i$ makes the RV error large. H and K flux is typically underestimated with such a large $v \sin i$. In our FEROS spectrum, an extra absorption is seen in the core of the Na D doublet. As it has a RV similar to that of the star and is characterized by a single-component very narrow line profile, we favor a circumstellar origin.

HD 189285 = BD-04 4987 = TYC 5155-1500-1 (ASAS 195924-0432.1) Proposed as a 90% probability member of AB Dor by Torres et al. (2008). At the <2.0 sigma level, its kinematics match only AB Dor. The target's age is also consistent with expectations for the AB Dor group, although it does appear slightly older. The analysis is therefore consistent with the AB Dor membership assignment. It should be noted that the Malo et al. (2013) and Gagné et al. (2014) Bayesian analysis tools, using our adopted parameters as inputs, predict only a 6% and <1%, respectively, probability of AB Dor membership at a distance of 83.5 pc. Given the age of the star that results

from age indicators, the AB Dor membership assignment is still possible. Messina et al. (2010) report a rotation period $P$ = 4.85 d.

HIP 98470 = HD 189245 = HR 7631 Fast-rotating F star, proposed by Nakajima & Morino (2012) as a member of the AB Dor moving group. Its kinematics do match any of the considered groups at the <2.0 sigma level. A low membership probability to AB Dor (3.9%) is obtained using the Malo et al. (2013) Bayesian analysis tools. The target's age from lithium, X-ray and Ca H and K appears quite young, comparable to the loci of AB Dor MG and Pleiades. However, considering these methods' limited age sensitivity for F-type stars, an age as old as 200-300 Myr is also possible. Baade & Kjeldsen (1997) flagged the star as SB but without further details. In contrast, Lagrange et al. (2009) found an RV dispersion of only 86 m/s, for 18 epochs over 259 days. The other sparse RV measurements on longer time baselines are consistent with a constant RV within errors. The CCF from our FEROS spectrum does not show signatures of additional components. No period is found in either ASAS or SuperWASP photometric data. A tentative period $P$ = 1.88 d is inferred from the HIPPARCOS photometric data.

TYC 5164-0567-1 = BD-03 4778 (ASAS 200449-0239.2) Proposed by Torres et al. (2008) as a 100% probability member of AB Dor. At the <1.0 sigma level, its kinematics match only AB Dor. The ages derived from various methods are also broadly consistent with the AB Dor group, but Li EW is larger than that of other members of similar color. Malo et al. (2013) Bayesian analysis tools predict a 98.5% probability of AB Dor membership at a distance of 66.0 pc. This predicted distance for membership is consistent with the photometric distance of 63.3 pc. On the other hand, the Gagné et al. (2014) online tool yields a very low membership probability. Messina et al. (2010) report a rotation period $P$ = 4.68 d, which was later confirmed by Kiraga (2012).

HIP 99273 = HD 191089 (ASAS 200905-2613.4; 1SWASP+J200905.21-261326.5) Proposed by Moór et al. (2006), Torres et al. (2008), and Malo et al. (2013) as a bona-fide member of β Pic. At the <1.0 sigma level, its kinematics match only β Pic. The membership is also supported by Gagné et al. (2014) online tool. The age indicators are somewhat ambiguous, as expected for an F-type star. The Lithium EW measured on our FEROS spectrum is compatible with a β Pic age, but also with significantly older ages; chromospheric and coronal emission are rather low. No period is found in ASAS or SuperWASP data. A tentative period $P$ = 0.488 d is derived from the HIPPARCOS data analysis, but this period is absent in the other datasets. We adopt β Pic membership and age, but allow for a maximum age of 200 Myr. Rhee et al. (2007) identify the star as SB, but without further details. The literature RVs show a modest scatter, which seems compatible with measurement errors, considering the early spectral type and the rotational velocity of the star. The star hosts a debris disk, with $T_{\text{dust}}$ = 95 K, $R_{\text{dust}}$ = 15 AU and $M_{\text{dust}}$ = $3.4 \times 10^{-2} M_⊕$ (Rhee et al. 2007). The disk was recently spatially resolved by Churcher et al. (2011).

HD 199058 (ASAS 205421+0902.4) New close visual binary ($\Delta H$ = 2.5 mag at 0.47 arcsec) identified by NaCo-LP observations. It also has a probable wide (245 arcsec projected separation) companion *TYC-1090-0543-1*, having very similar kinematic parameters and indicators supporting a young age. If a physical association is real, the projected separation is about 16000 AU. Both stars are included in the list of
AB Dor members by Torres et al. (2008). At the <2.0 sigma level, the kinematics of HD 199058 match also Tuc/Hor, Carina, and ϵ Cha. However, membership to Tuc/Hor or Carina is unlikely because of the star's northern declination. The star's sky position is inconsistent with ϵ Cha membership. The age indicators of both components are consistent with AB Dor membership. There is a discrepancy in the photometric distances of the two stars (55.0 pc for HD 199058, including binary correction, and 77.2 pc for TYC-1090-0543-1). It should be noted that Malo et al. (2013) Bayesian analysis tools predict only a 6% probability of AB Dor membership at a distance of 55.0 pc. This probability changes to >98% at 74 pc, a distance nearly identical to the photometric distance of TYC-1090-0543-1. On the other hand, Gagné et al. (2014) online tool yields a very low membership probability. We adopt the mean of the photometric distances of the two objects. Applying both Lomb-Scargle and Clean analyses in two seasons, we find an uncertain period P = 3.47 d for HD 199058.

TYC 5206-0915-1 = BD-07 5533 (ASAS 211834-0631.7) In ACVS, the star is listed with a period P = 3.4447 d and classified as a detached/semi-detached eclipsing binary. However, from our analysis of the photometric time-series we did not found convincing evidences for eclipses using this proposed period or their harmonics. Kiraga (2012) reports a period P = 2.37 d, which our analysis retrieves in all the seasons. From CCF in our FEROS spectrum, there are no indications of additional components. The large RV scatter (about 40 km s⁻¹ peak-to-valley) from our FEROS and CORALIE spectra and SACY makes the star a short period spectroscopic binary (SB1). The fast rotational period and large activity levels may be due to youth or due to a tidally locked binary. Lithium EW is consistent with a star of age intermediate between Pleiades and Hyades, but the possibility that this is an RS CVn variable with detectable lithium cannot be ruled out. The target has very large uncertainties in *UVW* velocities because of a large spread in measured RVs. Until a systemic velocity can be established and used to calculate *UVW*, determining group membership is not possible. Overall, age determination remains highly uncertain until the orbital period of the binary can be established.

HIP 105384 = HD 203019 (ASAS 212047-3846.9; 1SWASP+J212046.59-384653.2) The lack of lithium in the spectrum of this star (from SACY) indicates an age older than the Hyades. Coronal and chromospheric activity (the latter based on several independent sources) instead suggest a younger age (about 250 Myr). RV monitoring indicates a single star and the CCF does not show additional components. Therefore, we are not considering a tidally locked binary. No rotation period is detected in our analysis, but the star exhibits non-periodic photometric variability. The kinematics do not match any of the groups and associations investigated at the <2.0 sigma level. The kinematics are also not consistent with the nearby, young population. An age of about 500 Myr might be roughly compatible with the various indicators, considering the observed scatter at fixed age.

HIP 105612 = HD 202732 (ASAS 212327-7529.6) Lithium and chromospheric activity indicate an age similar to the Hyades. X-ray emission suggests a slightly younger age. We find an uncertain period P = 12.9 d in the complete series and in two seasons. The resulting gyrochronology age from this period would be about 1100 Myr, older than the other indicators. The kinematics do not match any of the groups

and associations investigated at the <2.0 sigma level and are also not consistent with the nearby, young population. The CCF does not show additional components and RV suggests a single star. Taking all these indications into account, we adopt an age of 700 Myr.

HIP 107684 = HD 207278 (ASAS 214849-3929.1) New close visual binary (Δ*H* = 2.8 mag at 0.33 arcsec). Proposed by Torres et al. (2008) as a 100% probability member of the AB Dor moving group. At the <2.0 sigma level, its kinematics match only AB Dor. Its estimated age is also consistent with AB Dor membership. Malo et al. (2013) Bayesian analysis tools predict a 92% probability of AB Dor membership at a distance of 81.0 pc. This predicted distance for membership is consistent with the measured distance of 90.2 pc. On the other hand, the Gagné et al. (2014) online tool yields a very low membership probability. Messina et al. (2010, 2011) report a rotation period P = 4.14 d.

HIP 108422 = HD 208233 (ASAS 215751-6812.8) Close visual binary discovered by Chauvin et al. (2003); the physical association of the components was confirmed with our NaCo observations (Chauvin et al. 2015). The star was included as a member of the Tuc association by Zuckerman & Song (2004) but rejected by Torres et al. (2008). Malo et al. (2013) also propose this star as a bona fide member of Tuc/Hor and the analysis based on Gagné et al. (2014) confirms membership. The star is characterized by a very fast rotation, identified both spectroscopically and photometrically. We find the period P = 0.4352 d, which is also reported by Koen & Eyer (2002) from HIPPARCOS data analysis and by Kiraga (2012) from ASAS data analysis. In our analysis, the kinematics match only Tuc/Hor but at the >2.0 sigma level. However, the kinematics might somewhat altered by binarity. The estimated age from lithium is consistent with the ~30 Myr age of Tuc/Hor. The star's isochrone age of 13 ± 3 Myr is formally even younger than the nominal Tuc/Hor group age. Taking all of these facts into consideration, we adopt a Tuc/Hor membership but acknowledge the possibility of an even younger age as suggested by the CMD position.

TYC 8004-0083-1 = CD-40 14901 (ASAS 224633-3928.8; 1SWASP+J224633.48-392845.2) All the age indicators point to a rather young star (best estimate of 90 Myr). However, the kinematics do not match any of the groups and associations investigated at the <2.0 sigma level. The kinematics are also not consistent with the nearby, young population. We find the period P = 3.22 d in all the ASAS and SuperWASP seasons. This period is also reported by Kiraga (2012).

HIP 114046 = HD 217987 = GJ 887 (ASAS 230552-3551.2) is the only M dwarf in our sample. It was included because of the tentative lithium detection in the SACY database (EW = 50 mÅ), which originally comes from de La Reza et al. (1981). However, our higher quality FEROS spectrum shows no lithium. The star is above the main sequence in the M_V vs. B-V color-mag diagram, which would imply a pre-MS star, but the 2MASS magnitudes are most compatible with a main sequence star. Delorme et al. (2012) estimated an isochrone age of 100 Myr–10 Gyr from VJHK photometry. The stellar radius, as derived by Demory et al. (2009) using VLTI, is not anomalous in their mass-radius and luminosity-radius relationships. The star has rather low coronal and chromospheric activity. No rotation period is found in either ASAS (sparse data) or HIPPARCOS data. Using the kinematic population diagnostic by Bensby et al. (2003), we conclude a probable membership of the thick disk. We therefore adopt
a very old age for the star, 8 Gyr. We adopt the stellar mass and metallicity from Neves et al. (2013).

TYC 9338-2016-1 = HD 220054 (ASAS 232153-6942.2) All age indicators are consistent with a young age (10–50 Myr). We find the period *P* = 1.875 d in ASAS and SuperWASP data. The same period was reported in ACVS by Bernhard et al. (2009), and by Kiraga (2012). RV measurements show some scatter (0.8 km s⁻¹ rms in SACY); we consider it as a suspected SB. The star’s kinematics match Tuc-Hor and TWA at the <2.0 sigma level. The star’s estimated age is also quite young. Malo et al. (2013) Bayesian analysis tools predict a very low probability of being a true member of one of those groups at the photometric distance of 99.6 pc. The kinematics are consistent with the nearby, young population.

TYC 9529-0340-1 = CD-86 147 (ASAS 232749-8613.3) Proposed by Torres et al. (2008) as an 85% probability member of Tuc/Hor. At the <1.0 sigma level, its kinematics match only Tuc/Hor. The ages derived from various methods are also consistent with the Tuc/Hor association. The Malo et al. (2013) Bayesian analysis tools predict 100% probability of Tuc/Hor membership at a distance of 64.0 pc. This predicted distance for membership is consistent with the photometric distance of 68.8 pc. The Gagné et al. (2014) online tool yields a 74% membership probability. Messina et al. (2010) report a rotation period *P* = 2.31 d, which they note to be inconsistent with *v sin i* = 73.9 km s⁻¹. A new analysis, also made with the Clean method, reveals a period *P* = 0.7025 d, which confirms the rotation period *P* = 0.6975 d found by Kiraga (2012) and *P* = 0.7024 d found in ACVS.

TYC 9339-2158-1 = CD-69 2101 (ASAS 233101-6905.2) The star shares common proper motion, position, and radial velocity with *HIP 116063 = HD 221231*. Parallax of the companion is adopted for the system. No rotation period is found (likely due to the blending of the components). The age of the components from several diagnostics is estimated to be 300 Myr.

TYC 6406-0180-1 = HD 221545 Lithium EW and X-ray luminosity of this K0 star indicate an age of about 200 Myr. Kinematics derived assuming an MS status are consistent with a moderately young star. Non-typical of a star of this type, a period *P* = 36.271 d is reported by ACVS and confirmed by Kiraga (2012), who reports *P* = 36.34 d. Our analysis of ASAS data reveals two major power peaks in the seasonal periodograms, one at *P* = 36 d and another at *P* = 1.026 d. The first agrees with the mentioned literature values, whereas the latter, with a K-type MS stellar radius and the small *v sin i* value, would imply a very inclined (almost pole-on) star. In the latter case, we would not expect any light rotational modulation, whereas we find a light curve amplitude up to Δ*V* = 0.07 mag. We therefore consider the period *P* = 36 d as “confirmed”. Such a rotation period being consistent with the measured *v sin i* = 5.5 km s⁻¹ requires a stellar radius *R* > 3 *R*₀. Large radii like this are found among subgiant K stars but not in the current *V* class assignation. The long rotation period is also unusual among active main-sequence stars, but typical of evolved stars. There is only one RV measurement in the literature. Therefore, limited inferences on binarity can be made. We adopt the main sequence age but allow for an age of 4 Gyr, which is obtained for an evolved star matching the stellar radius that is most consistent with the rotation period and *v sin i*.

*HIP 116910 = HD 222575 (ASAS 234154-3558.7)* Proposed by Torres et al. (2008) and Malo et al. (2013) as a

<figure><img src="image_15.png" /><figcaption>Fig. C.1. Calibration of the instrumental *S* index measured on FEROS spectra onto the standard Mt. Wilson scale.</figcaption></figure>

high-probability member of AB Dor. The Gagné et al. (2014) online tool yields a membership probability of 36%. At the <1.0 sigma level, the kinematics match only AB Dor. The ages derived from various methods are slightly younger than the proposed age of the AB Dor group; however since the kinematics only match this group and the star is surely young, the analysis reinforces the AB Dor membership assignment. Messina et al. (2011) report a rotation period *P* = 1.787 d, which was subsequently confirmed by Kiraga (2012).

## Appendix C: *S* index calibration for FEROS

The instrumental *S* index was measured on FEROS spectra by integrating the flux over rectangular bandpasses that are 1 Å wide, as in Desidera et al. (2006). For a calibration onto the standard Mount Wilson scale, we used 73 spectra of 42 stars from the lists of Baliunas et al. (1995) and Wright et al. (2004). The relevant calibration stars were observed in the same nights as were our program stars and reduced in the same way. We determined that the inclusion of additional calibration stars from other sources, which are typically characterized by single-epoch measurements (e.g., Henry et al. 1996), increases the scatter of the calibration. A linear fit between FEROS instrumental *S* index and the literature calibrated *S* index was found to be fully adequate (Fig. C.1). The rms of residuals from the calibration is about 5%. To better understand the measurement errors, we plotted the absolute value of the difference between our calibrated *S* index and the literature ones in Fig. C.2. The stars with larger differences are those that are more active and have a small number of measurements in the calibration papers. This indicates that the intrinsic variability of chromospheric activity has a significant impact on our calibration. For the low-activity, low-variability star τ Ceti, the observed rms of the *S* index for 15 spectra is 0.0034 (2%). It should be further noted that the measured *S* index is underestimated for stars with
<figure><img src="image_16.png" /><figcaption>**Fig. C.2.** Absolute value of the difference between calibrated FEROS *S* index and literature values as a function of literature *S* index. Different symbols refer to stars with a different number of measurements available in the literature. The stars with the largest offsets all have small numbers of measurements in the literature, supporting the intrinsic variability of chromospheric emission as the main source of the observed scatter in the calibration.</figcaption></figure>

$v \sin i > 40 \text{ km s}^{-1}$, as part of the H and K emission lies outside the defined integration windows (Desidera et al. 2006). The calibrated *S* index was transformed into the chromospheric flux $\log R_{\text{HK}}$ by following the prescriptions by Noyes et al. (1984).

<figure><img src="image_17.png" /><figcaption>**Fig. D.1.** Example of photometric analysis for the target HIP 79958.</figcaption></figure>

**Appendix D: Details on rotation analysis**

We present here some additional details on the result of our search for rotation periods. For the targets with newly determined rotation periods, or confirmed literature values, we list in Table D.1 the following: (1) the time interval spanned by each segment; (2) the number of *V* magnitude measurements; (3) the brightest *V* magnitude; (4) the light curve amplitude, which is measured as the amplitude of the sinusoid fit to the phased light curve; (5) the photometric accuracy; (6) the ratio of the average residuals from the fit on the light curve amplitude; (7) the rotation period; (8) the rotation uncertainty; (9) the normalized power of the periodogram peak, corresponding to the rotation period, and the power level corresponding to a 1% false alarm probability; and (10) the sequential number of the timeseries segment. The number 1 indicates the complete unsegmented timeseries.

Figure D.1 shows, as an example, the results of our period search for HIP 79958. In the left column, we plot the *V* magnitude time series (complete in the top left panel, and segmented in the other lower panels). In the middle column, we plot the Lomb-Scargle periodograms with an indication of the power level corresponding to the 1% FAP, and the peak corresponding to the rotation period. In the right column, we plot the phased light curve with the rotation period. The initial epoch is the same for all the light curves, whereas the rotation period is the one found in the corresponding season. In the seasons where no period is detected, we used the rotation period found from the whole time series analysis. In the bottom panels, we have multiplied all the periodograms and extracted the most significant periodicities. This represents a different approach to reveal peaks that are low power but persistent in each season. For all the targets that we newly determined, or confirmed, the rotation period, similar plots are available as online material.