The orbits of five single-lined spectroscopic binaries have recently been determined. We now use astrometric measurements that were collected with the Hipparcos satellite to constrain the systems' mass ratios and secondary masses. The barycentric astrometric orbits of three binary systems, HD 140667, HD 158222, and HD 217924, are fully determined and precise estimates of their mass ratios are obtained. Follow-up of these systems with infrared spectroscopy could yield model-independent dynamical masses for all components.

We have determined an improved orbit for the bright, evolved, double lined binary γ Canis Minoris. The system has an orbital period of 389.31 days and an eccentricity of 0.2586. We have revised the secondary to primary mass ratio to 0.987. The spectral types of the primary and secondary are K4 III and K1: III, respectively, and the components have a V magnitude difference of 2.2. Orbital fits to the Hipparcos astrometry are not definitive, but they suggest an orbital inclination of ∼ 66°, which produces masses of 1.88 and 1.85 M⊙ for the components. A comparison with evolutionary tracks results in an age of 1.3 Gyr. STELLA very low amplitude radial velocity residuals of the secondary indicate a period of 278 days. We interpret this as the rotation period of the secondary, detectable because of star spots rotating in and out of view. This period is nearly identical to the pseudosynchronous rotation period of the star. The primary is rotating more slowly than its pseudosynchronous rate. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The extraordinarily short orbital period given for HD 31738 in this Magazine in 2009 was mistaken. The true value, a 1-day(-1) alias of the published one, is even shorter, 0-3102061 days.

Aims. We present a detailed analysis of the star HD 6286 = BE Psc from 16 years of spectroscopic observations and 18 seasons of photometric ones. The star is an evolved, chromospherically active, eclipsing binary, consisting of a K1 giant plus an F6 dwarf/subgiant in a circular orbit with a period of 35.671 days. A faint, close visual companion of spectral type ≈ G0 makes the system triple. The orbital inclination of the eclipsing pair is 81$\fdg$8. Methods. We have obtained simultaneous solutions with our extensive set of radial velocities and $\it BVI$ light curves that include the star spot variability of the K giant, the ellipticity of the K giant, and the eclipses of the spectroscopic binary system. Results. Our spot solutions suggest persistent polar spots, one in each hemisphere, that are cooler than the surrounding photosphere by $810\pm150$ K over the timespan of our observations. The K giant and the F6 dwarf/subgiant have masses of 1.56 $M_{\odot}$ and 1.31 $M_{\odot}$ and mean radii of 12.0 and 1.9 $R_{\odot}$, respectively. The masses have uncertainties of just ≈ 1.5%. No irradiation effect was detected. We compared our results to theoretical evolutionary tracks that suggest an age for the system of ≈ 2.7 Gyr. The modest logarithmic lithium abundance of the primary of 1.30 (upper limit) indicates that the star may have already experienced its first dredge up. The rotation period of the primary is $35.49 \pm 0.01$ days and appears to be synchronized with the orbital period of the eclipsing pair to within 0.5%. Our data are inconclusive as to whether the secondary is synchronized. Conclusions. Circularization of the orbit has taken place, and we conclude that the rapid increase in the size of the K giant, as it evolved across the Hertzsprung gap and up the base of the giant branch, likely caused the orbit to become circular.

We have used new spectroscopic and photometric observations of HD 149420 to obtain an improved orbital element solution and determine some basic properties of the system. This double-lined binary has an orbital period of 3.39430 days, a circular orbit, and a mass ratio of 0.52. The primary is somewhat evolved, with an A9 IV spectral type, while the secondary is estimated to be an F5: dwarf. The secondary may be synchronously rotating, but the primary is rotating substantially slower than its synchronous velocity. Our photometric observations confirm the light variability and period found by Hipparcos. We determine a photometric period of 1.698 days, essentially half the value of the orbital period, with a peak-to-peak amplitude of 0.028 mag in V. In addition to this ellipsoidal light variation, we also detect more rapid, low-amplitude variability with a period of 0.076082 days and a peak-to-peak V amplitude of 0.008 mag, as well as a possible second short 0.059256 day period with a peak-to-peak amplitude of only 0.005 mag. This indicates that the A9 IV primary in HD 149420 is a pulsating δ Scuti variable. Our binary model that best fits both the radial velocity and photometric observations indicates the possibility of extremely shallow grazing eclipses, a circumstance not unexpected given the large minimum masses from the orbital solution, the evolved nature of the primary, and the short orbital period.

Radial velocities from the 2.1 m telescope at McDonald Observatory supplemented with radial velocities from the coudé feed telescope at Kitt Peak National Observatory provide new precise orbits for the double-lined spectroscopic binaries RR Lyn (A3/A8/A6), 12 Boo (F8 IV), and HR 6169 (A2 V). We derive orbital dimensions (a1 sin i and a2 sin i) and minimum masses (m1 i and m2 i) with accuracies of 0.06%-0.9%. The three systems, which have V magnitudes of 5.53, 4.82, and 6.42, respectively, are all sufficiently bright that they are easily within the grasp of modern optical interferometers and so afford the prospect, when our spectroscopic observations are complemented by interferometric observations, of fully determined orbits, precise masses, and distances. In the case of RR Lyn, which is also a detached eclipsing binary with a well-determined orbital inclination (i = 87.°45 ± 0.°11), we are able to determine the semimajor axis of the relative orbit, a = 29.32 ± 0.04 R⊙; primary and secondary radii of 2.57 ± 0.02 and 1.59 ± 0.03 R⊙, respectively; and primary and secondary masses of 1.927 ± 0.008 and 1.507 ± 0.004 M⊙, respectively. Comparison of our new systemic velocity determination, γ = -12.03 ± 0.04 km s-1, with the earlier one of Kondo, γ = -11.61 ± 0.30 km s-1, shows no evidence of any change in the systemic velocity in the 40 yr separating the two measurements, a null result that neither confirms nor contradicts the presence of the low-mass third component proposed by Khaliullin & Khaliullina. Our spectroscopic orbit of 12 Boo is more precise than that of Boden et al. but confirms their results about this system. Our analysis of HR 6169 has produced a major improvement in its orbital elements. The minimum masses of the primary and secondary are 2.20 ± 0.01 and 1.64 ± 0.02 M⊙, respectively. Although all three systems have eccentric orbits, the six components of the systems are either pseudosynchronously rotating or very nearly so.

We have computed, using 17 infrared radial velocities, the first set of orbital elements for the M giant in the symbiotic binary V2116 Ophiuchi. The giant's companion is a neutron star, the bright X-ray source GX 1+4. We rule out the previously proposed period of 304 days and instead find an orbital period of 1161 days, by far the longest of any known X-ray binary. The orbit has a modest eccentricity of 0.10, with an orbital circularization time of ≲5 × 106 yr. The large mass function of the orbit significantly restricts the mass of the M giant. Adopting a neutron star mass of 1.35 M☉, the maximum mass of the M giant is 1.22 M☉, making it the less massive star. Spectrum synthesis analysis of several infrared spectral regions results in slightly subsolar abundances for most metals. Carbon and nitrogen are in the expected ratio resulting from the red-giant first dredge-up phase. The lack of 17O suggests that the M giant has a mass less than 1.3 M☉, consistent with our maximum mass. The surface gravity and maximum mass of the M giant result in a radius of 103 R☉, much smaller than its estimated Roche lobe radius. Thus, the mass loss of the red giant is via a stellar wind. These properties argue that the M giant is near the tip of the first-ascent giant branch. Although the M-giant companion to the neutron star has a mass similar to the late-type star in low-mass X-ray binaries, its near-solar abundances and apparent runaway velocity are not fully consistent with the properties of this class of stars. Thus, in many ways this symbiotic X-ray binary system is unique, and various scenarios for its possible evolution are discussed.

We have obtained spectroscopy and photometry of three chromospherically active, single-lined spectroscopic binaries, HD 37824 (V1149 Ori), HD 181809 (V4138 Sgr), and HD 217188 (AZ Psc). HD 37824 has a circular orbit with a period of 53.57 days. Its primary is a K0 III star, while the secondary is likely a G or K dwarf. HD 181809 has an orbit with a period of 13.04667 days and a low eccentricity of 0.040. The primary has a spectral type of K0 III–IV, and its secondary is probably an M dwarf. The orbit of HD 217188 has a period of 47.1209 days and a moderately high eccentricity of 0.470. The spectral type of the primary is K0 III, while the secondary is likely an M dwarf. All three systems are estimated to have near solar iron abundances. Photometric observations spanning 15–16 years for all three stars yield mean photometric periods of 53.12, 59.85, and 90.89 days for HD 37824, HD 181809, and HD 217188, respectively. Thus, HD 37824 is rotating synchronously with the orbital period, while HD 181809 and HD 217188 are both rotating considerably slower than synchronously. All three stars show long-term variations in mean brightness and photometric amplitude, but no correlations are observed between the seasonal mean brightness, photometric amplitude, and seasonal photometric period in any of the stars. No clear evidence for long-term periodic variations in any of these parameters is present. The circular orbit of HD 37824 and the synchronous rotation of its K giant argue that the star is in the core helium-burning phase of its evolution. The giant components of HD 181809 and HD 217188 are asynchronous rotators, and both systems have eccentric orbits. Thus, those two stars are likely first-ascent giants.

In this paper we present radial velocity curves of AGB variables that exhibit various kinds of anomalies: semiregular variables (SRVs) with typical mira periods, SRVs exceeding the mira 2.5 mag amplitude limit, miras with secondary maxima in their light curves, and a SRV with a long secondary period. The stars with reliable Hipparcos parallaxes from this and from previous studies are plotted in a log P-M-K-diagram. Our objects nicely follow the log P-M-K-relations determined for the LMC. This allows the pulsation mode to be identified. While all miras fall on the fundamental mode sequence, the SRVs fall on both the first overtone and fundamental mode sequences. The SRVs on the fundamental mode sequence occur at both high and low luminosities, some of them being more luminous than larger amplitude miras. This demonstrates observationally that some parameter other than luminosity affects the stability of long period variables, probably mass. First overtone pulsators all show velocity amplitudes around 4 km s(-1). For the fundamental mode pulsators, the velocity amplitude shows a correlation with light amplitude. The two miras R Cen and R Nor, known for their double-peaked light curves, have velocity curves that are quite different. The R Nor velocity curve shows no evidence of the double peaks, meaning that the true pulsation period is the time between alternate minima or maxima. There is slight evidence for a double bump in the R Cen velocity curve. It is suggested that these stars are relatively massive (3 - 5 M-.).

New spectroscopic and photometric observations of HD 144110 have been used to obtain an improved orbital element solution and determine some basic properties of the system. This chromospherically active, double-lined spectroscopic binary has an orbital period of 1.6714012 days and a circular orbit. We classify the components as G5 V and K0 V and suggest that they are slightly metal-rich. The photometric observations indicate that the rotation of HD 144110 is synchronous with the orbital period. Despite the short orbital period, no evidence of eclipses is seen in our photometry.

We have discovered the first example of a star pulsating intrinsically with both γ Doradus and δ Scuti frequencies. The star, HD 8801, is an Am metallic-line star that appears to be single. Since the vast majority of Am stars are members of binary systems with periods less than 1000 days and also do not pulsate, HD 8801 possesses a very unusual, if not unique, combination of physical properties. Our photometry, acquired with an automatic telescope at Fairborn Observatory, resolves six independent pulsation periods between 0.048 and 0.404 days. The two longest periods lie within the range of γ Dor variables, while the four shorter periods are within the range of δ Sct stars. Eleven radial velocities, obtained over an 11 month period, have a mean of 0.8 ± 0.3 km s-1, providing no evidence for a spectroscopic companion. The star is on the main sequence and lies within both the γ Dor and δ Sct instability strips. Pulsation constants computed for the six periods agree with pulsation constants computed for other γ Dor and δ Sct variables. HD 8801 is also the first confirmed case of a metallic-line star pulsating with γ Dor frequencies. Its projected rotational velocity of 55 km s-1 is typical for Am stars, which, as a group, rotate more slowly than normal A stars. HD 8801's slow rotation compared to normal A stars does not appear to arise from either a binary companion or evolutionary expansion and thus remains a puzzle. The coexistence of metallicism and pulsation in several main-sequence stars near the red edge of the δ Sct strip contradicts recent models that predict pulsations only in more evolved stars.

We present near infrared velocity curves for 12 long period variables (LPVs) in the globular cluster 47 Tuc (NGC 104). New light curves are also presented for these variables. Results are compared with the period-luminosity sequences occupied by the LPVs in the LMC. Sequence C variables ( fundamental mode pulsators) have larger velocity amplitudes than sequence B variables ( first overtone pulsators). We show that, at similar luminosities, higher mass loss rates are associated with larger pulsation amplitudes. One variable (V18) does not fit the normal period luminosity sequences and it has an unusually large amount of circumstellar dust, suggesting that it has recently undergone a thermal pulse on the AGB. Finally, we report the discovery of three new long period variable stars in the cluster core, all previously found to have a large infrared excess.

We present new high-dispersion spectroscopic and precise photometric observations to identify 11 new γ Doradus variables. Seven of these new γ Doradus stars appear to be single, three are primaries of single-lined binaries, and one has two distant visual companions; none are double-lined or close visual binaries. Several of the stars show spectroscopic line-profile and low-amplitude radial velocity variability indicative of pulsation. All 11 stars are photometrically variable with amplitudes between 8 and 93 mmag in Johnson B and periods between 0.398 and 2.454 days. One star is monoperiodic; the rest have between two and five independent periods. The variability at all periods approximates a sinusoid, although three of the stars exhibit cycle-to-cycle variation in the level of maximum brightness, similar to the Blazhko effect observed in some RR Lyrae stars. We provide a new tabulation of all 54 γ Doradus stars confirmed to date and list some of their properties. All are dwarfs or subgiants and lie within a well-defined region of the H-R diagram that overlaps the cool edge of the δ Scuti instability strip. Four of the new γ Doradus variables from this paper also lie within the δ Scuti instability strip but do not exhibit the additional higher frequency variability typical of δ Scuti stars. The variability type of several of these stars given in the General Catalog of Variable Stars and in SIMBAD should now be revised.

Two interacting binary systems, V2116 Oph and HR 4049, are discussed. These systems both are evolved and contain disks but are otherwise very different. Both cases illustrate the role the measurement of cosmic abundances can have in understanding the evolutionary history of stellar systems.

The Ninth Catalogue of Spectroscopic Binary Orbits (http://sb9.astro.ulb.ac.be) continues the series of compilations of spectroscopic orbits carried out over the past 35 years by Batten and collaborators. As of 2004 May 1st, the new Catalogue holds orbits for 2386 systems. Some essential differences between this catalogue and its predecessors are outlined and three straightforward applications are presented: (1) completeness assessment: period distribution of SB1s and SB2s; (2) shortest periods across the H-R diagram; (3) period-eccentricity relation.

Projected rotational velocities for 67 B, A, and early-F stars have been determined. Some of these stars are early-type, radial-velocity standard candidates. The spectra of seven stars show metallic lines with composite profiles that consist of a narrow component near the center of a broad component, suggesting that they may be shell stars or binaries.

HD 7205 is a recently discovered visual binary. The primary star is a chromospherically active, single-lined binary, making the system triple. From spectroscopic observations, the orbit of the primary has a period of 18.01335 days and a moderate eccentricity of 0.197. The primary's spectral type is G8 IV-V. The unseen secondary of the short-period binary is likely an M dwarf, while the visual binary secondary is probably a K3 dwarf. From solar-abundance evolutionary tracks, the primary has a mass of similar to1.0 M-circle dot and an age of about 10 Gyr. It has evolved off the main sequence and is approaching the base of the red giant branch. Its rotation period of 21.3 days is significantly different from its pseudosynchronous rotation period of 14.6 days, making it an asynchronous rotator.

The Ninth Catalogue of Spectroscopic Binary Orbits (http://sb9.astro.ulb.ac.be) continues the series of compilations of spectroscopic orbits carried out over the past 35 years by Batten and collaborators. As of 2004 May 1st, the new Catalogue holds orbits for 2386 systems. Some essential differences between this catalogue and its predecessors are outlined and three straightforward applications are presented: (1) completeness assessment: period distribution of SB1s and SB2s; (2) shortest periods across the H-R diagram; (3) period-eccentricity relation.

HD 18955 is a double-lined spectroscopic binary with a period of 43.3214 days and a high eccentricity of 0.761. The spectral types of the components are K0 V and K2–K3 V. The secondary is a typical early K dwarf, although its minimum mass is greater than canonical values. However, this larger mass is consistent with other early K dwarf, spectroscopic binary results. The primary is anomalous, being substantially underluminous for its radius and mass, which are equal to or slightly greater than solar values. A lack of lithium argues that the components are not pre–main-sequence stars. The large minimum masses of both components suggest that the system has a high orbital inclination. Our photometric observations around the times of conjunction show no evidence of eclipses, but considering the uncertainties in the ephemerides, there is only a 50% chance that our photometric observations would have detected the primary eclipse and almost no chance that we covered the secondary eclipse. Hence, eclipses remain a real possibility in this system. Photometric variations with an amplitude of 0.02 mag reveal a period of 7.55 days, which is assumed to be the primary star's rotation period. Thus, given the spectral types of the stars, this system is a BY Draconis type variable. With v sin i values of 5 km s-1 for both components, the two stars are rotating more rapidly than typical K dwarf field stars, but the observed rotation period is still substantially longer than the predicted pseudosynchronous rotation period of 4.6 days for the primary.