Hipparcos Stars Research Articles

Verification of Astrometrically Accelerating Stars from Hipparcos and Gaia. I. Methodology and Application to HIP 44842

A large number of candidate binary stars with apparent acceleration on the sky has emerged from analysis of astrometric data collected by the Hipparcos, Tycho-2, and Gaia space missions. Although the apparent acceleration can serve as a relatively reliable indicator of binarity, it provides scarce information about the orbital and physical parameters of the components. With an emphasis on the search for stellar-mass black holes and neutron stars hidden in binary systems, we start a broader effort to characterize the most promising candidates using follow-up ground-based observations. Accurate quantification of orbital and physical parameters of systems with dim or invisible companions requires combination of Hipparcos, Gaia, and precision spectroscopic measurements. In this paper, we review the necessary steps in this implementation and describe the improved Hipparcos–Gaia sample of long-term astrometric accelerations, which includes correction of sky-correlated systematic errors using the vector spherical decomposition method. As an example, we study one Hipparcos star with a large acceleration, HIP 44842, where the companion is revealed to be a normal main-sequence star.

Stellar and substellar companions from Gaia EDR3

Context. The multiplicity fraction of stars, down to the substellar regime, is a parameter of fundamental importance for stellar formation, evolution, and planetology. The census of multiple stars in the solar neighborhood is however incomplete. Aims. Our study is aimed at detecting companions of HIPPARCOS catalog stars from the proper motion anomaly (PMa) they induce on their host star, namely, the difference between their long-term HIPPARCOS-Gaia and short-term Gaia proper motion vectors. We also aim to detect resolved, gravitationally bound companions of the HIPPARCOS catalog stars (117 955 stars) and of the Gaia EDR3 stars closer than 100 pc (542 232 stars). Methods. Using the HIPPARCOS and EDR3 data, we revised the PMa catalog for the HIPPARCOS stars. In order to identify gravitationally bound visual companions of our sample, we searched the Gaia EDR3 catalog for common proper-motion (CPM) candidates. Results. The detection of tangential velocity anomalies with a median accuracy of σ(ΔvT) = 26 cm s−1 per parsec of distance is demonstrated with the EDR3. This improvement by a factor 2.5 in accuracy, as compared to Gaia DR2, results in PMa detection limits on companions that are well into the planetary mass regime for many targets. We identify 37 515 HIPPARCOS stars presenting a PMa at significant level (S/N > 3), namely, a fraction of 32% (compared to 30% for the DR2) and 12 914 (11%) hosting CPM bound candidate companions. After including the Gaia EDR3 renormalised unit weight error (RUWE > 1.4) as an additional indicator, 50 720 stars of the HIPPARCOS catalog (43%) exhibit at least one signal of binarity. Among the Gaia EDR3 stars located within 100 pc, we find CPM bound candidate companions for 39 490 stars (7.3% of the sample). Conclusions. The search for companions using a combination of the PMa, CPM, and RUWE indicators significantly improves the exhaustivity of the multiplicity survey. The detection of CPM companions of very bright stars (heavily saturated on the Gaia detectors) that are classical benchmark objects for stellar physics provides a useful proxy for estimating their distance with a higher accuracy than with HIPPARCOS.

Latitude observations of the last century to obtain accurate independent latitude stations (INDLS) catalog of μδ for 682 Hipparcos stars and comparison with Gaia DR2

AbstractThe independent latitude stations (INDLS) catalog of proper motion in declination μδ for 682 bright Hipparcos (HIP) stars is presented. It is obtained in the Hipparcos reference frame, and only the Hipparcos mean position at epoch 1991.25 is used for INDLS data to calculate independent μδ (the HIP μδ values are not included in the INDLS data). Catalog comparisons were made in pairs for the four catalogs (HIP, new Hipparcos—NHIP, Gaia DR2, INDLS) to look for possible systematic differences as a function of brightness, color, and position coordinates (α, δ). All catalogs were found to be in agreement, except 0.21 mas year−1 for differences in INDLS–DR2 in line with the brightness; −0.13 and 0.24 mas year−1 for differences in HIP–DR2 in line with the free term and brightness, respectively; and −0.16, 0.23, and 0.13 mas year−1 for differences NHIP–DR2 in line with the free term, brightness, and color, respectively. A slightly better consistency is observed in the cases of INDLS–NHIP and INDLS–DR2 than HIP–DR2 and NHIP–DR2. The systematic error is in line with brightness on the level 0.1 mas year−1 in DR2 and, near 0.1 mas year−1, in line with color. An indication that the bright reference frame of DR2 rotates by about 0.1 mas year−1 relative to the faint quasar frame is in line with a presented sinusoidal curve of differences μδ as a function of α. Its amplitude is A = 0.53 ± 0.11 mas year−1 for INDLS–DR2 (0.26 ± 0.07 for INDLS–NHIP); about 0.2 belongs to DR2. The level of formal errors is near 1.9 mas year−1 for the case INDLS–DR2 and near 1.5 for: INDLS–NHIP, HIP–DR2, and NHIP–DR2. The values μδ of bright DR2 stars could be underestimated; the astrometry is unreliable for G ≤ 6 mag due to detector saturation.

Comparison of proper motions in declination for 387 Gaia DR2 and HIPPARCOS stars from ILS observations over many decades

Context. The second solution of the Gaia catalog, which has been available since April 2018, plays an important role in the realization of the future Gaia reference frame. Since 1997, the reference frame has been materialized by the optical HIPPARCOS positions of about 120 000 stars. The HIPPARCOS has been compared with and linked to the International Celestial Reference Frame (ICRF). The ICRF is materialized by means of the radio positions of extragalactic sources using very large baseline interferometry observations. Both, the HIPPARCOS and Gaia missions belong to the European Space Agency, and it is important to note that the Gaia catalog is going to replace the HIPPARCOS catalog. Aims. It has been shown that the International Latitude Service zenith telescope data pertaining to ground-based surveys that span a time baseline of about 80 yr, and which are also key when measuring proper motions, could be useful for the accurate determination of μδ for 387 ILS stars. Therefore, in this study we aim first to reduce these stars to the HIPPARCOS reference system; second, to made our original catalog of μδ, which we refer to as the ILS catalog, for these 387 bright stars; third, to present comparison results of the four catalogs by pairs (the ILS, HIPPARCOS or HIP, new HIPPARCOS or NHIP, and Gaia DR2); and fourth, to analyze the differences in μδ between pairs of catalogs to characterize the μδ errors for these catalogs with a special focus on the Gaia DR2 and ILS catalogs. Methods. At seven ILS sites around the world at latitude 39.°1, a set of seven telescopes was used to monitor the latitude variation via observations of the same stars for about 80 yr. Here, the inverse task was applied to improve μδ values of the 387 HIPPARCOS stars using the previously mentioned observations. Due to the specific Horrebow-Talcott method of the measured star pair, it is difficult to determine μδ for each single star. However, we achieved this by developing the original method and in combination with the HIPPARCOS data. We used the previously developed least squares method and formula to determine the coefficients, which describe the systematic part of differences in μδ between the pairs of catalogs. Results. We calculated the coefficients with the aforementioned formula (in line with the coordinates, stellar magnitude, and color index of every star) to compare ILS, HIP, NHIP, and Gaia DR2 data of μδ against each other by using the set of 387 stars. The presented differences of μδ show that the systematic errors in the four catalogs are nearly at the same level of 0.1 mas yr−1. This means that the DR2 and ILS μδ values are in good agreement with each other, and with values from the HIPPARCOS and new HIPPARCOS catalogs. Also, the random errors of differences are small ones; they are near 1 mas yr−1 for ILS-HIP and ILS-NHIP, and about 2 mas yr−1 for ILS-DR2, HIP-DR2, and NHIP-DR2. It is important to note that there is a similar level of proper motion formal errors in HIPPARCOS and new HIPPARCOS catalogs.

A catalog of spectroscopic binary candidate stars derived from a comparison of Gaia DR2 with other radial velocity catalogs

AbstractUsing the recently published Gaia second data release that includes measurements of the mean radial velocity of about 7.2 million stars, we performed a systematic comparison with other existing radial velocity catalogs to search for variations in the radial velocity measurements, with the goal that detected differences may indicate that these stars are possibly spectroscopic binary stars with only one visible component (SB1). We present a catalog of spectroscopic binary candidate stars containing 35,246 stars, compiled to encourage follow‐up observations obtaining spectra at different epochs of orbits of these stars to verify their binarity and to study these systems using radial velocity curves. Comparing the Gaia DR2 database with the K‐M dwarf catalog, we found 16 stars that show radial velocity variations. In a comparison with the Pulkovo radial velocity catalog of Hipparcos stars, we identified a total of 539 SB1 candidate stars. In the largest radial velocity catalog available, the radial velocity experiment (RAVE) catalog, we found a total of 34,691 stars that show radial velocity variations when compared to the Gaia DR2 data.

The Hipparcos–Gaia Catalog of Accelerations

Abstract This paper presents a cross-calibrated catalog of Hipparcos and Gaia astrometry to enable their use in measuring changes in proper motion, i.e., accelerations in the plane of the sky. The final catalog adopts the reference frame of the second Gaia data release (DR2) and locally cross-calibrates both the scaled Hipparcos–Gaia DR2 positional differences and the Hipparcos proper motions themselves to this frame. This gives three nearly independent proper motion measurements per star, with the scaled positional difference usually being the most precise. We find that a linear combination of the two Hipparcos reductions is superior to either reduction on its own and address error inflation for both Hipparcos and Gaia DR2. Our adopted error inflation is additive (in quadrature) for Hipparcos and multiplicative for Gaia. We provide the covariance matrices along with the central epochs of all measurements. Our final proper motion differences are accurately Gaussian with the appropriate variances and are suitable for acceleration measurements and orbit fitting. The catalog is constructed with an eye toward completeness; it contains nearly 98% of the Hipparcos stars. It also includes a handful of spurious entries and a few stars with poor Hipparcos reductions that the user must vet by hand. Statistical distributions of accelerations derived from this catalog should be interpreted with caution.

Spectroscopic orbits of nearby solar-type dwarfs – II.

Several nearby solar-type dwarfs with variable radial velocity were monitored to find their spectroscopic orbits. First orbital elements of 15 binaries (HIP 12144, 17895, 27970, 32329, 38636, 39072, 40479, 43004, 73700, 79234, 84696, 92140, 88656, 104514, and 112222) are determined. The previously known orbits of HIP 5276, 21443, 28678, and 41214 are confirmed and updated. The orbital periods range from 2 days to 4 years. There are 8 hierarchical systems with additional distant companions among those 19 stars. The outer visual orbit of the triple system HIP 17895 is updated and the masses of all its components are estimated. We provide radial velocities of another 16 Hipparcos stars without orbital solutions, some of those with long periods or false claims of variability.

The Solar Neighborhood. XXXIX. Parallax Results from the CTIOPI and NOFS Programs: 50 New Members of the 25 parsec White Dwarf Sample

Abstract We present 114 trigonometric parallaxes for 107 nearby white dwarf (WD) systems from both the Cerro Tololo Inter-American Observatory Parallax Investigation (CTIOPI) and the U. S. Naval Observatory Flagstaff Station (NOFS) parallax programs. Of these, 76 parallaxes for 69 systems were measured by the CTIOPI program and 38 parallaxes for as many systems were measured by the NOFS program. A total of 50 systems are confirmed to be within the 25-pc horizon of interest. Coupled with a spectroscopic confirmation of a common proper-motion companion to a Hipparcos star within 25 pc as well as confirmation parallax determinations for two WD systems included in the recently released Tycho Gaia Astrometric Solution catalog, we add 53 new systems to the 25-pc WD sample—a 42% increase. Our sample presented here includes four strong candidate halo systems, a new metal-rich DAZ WD, a confirmation of a recently discovered nearby short-period (P = 2.85 hr) double degenerate, a WD with a new astrometric perturbation (long period, unconstrained with our data), and a new triple system where the WD companion main-sequence star has an astrometric perturbation (P ∼ 1.6 year).

Fundamental parameters and infrared excesses of Tycho–Gaia stars

Effective temperatures and luminosities are calculated for 1,475,921 Tycho-2 and 107,145 Hipparcos stars, based on distances from Gaia Data Release 1. Parameters are derived by comparing multi-wavelength archival photometry to BT-Settl model atmospheres. The 1-sigma uncertainties for the Tycho-2 and Hipparcos stars are +/-137 K and +/-125 K in temperature and +/-35 per cent and +/-19 per cent in luminosity. The luminosity uncertainty is dominated by that of the Gaia parallax. Evidence for infrared excess between 4.6 and 25 microns is found for 4256 stars, of which 1883 are strong candidates. These include asymptotic giant branch (AGB) stars, Cepheids, Herbig Ae/Be stars, young stellar objects, and other sources. We briefly demonstrate the capabilities of this dataset by exploring local interstellar extinction, the onset of dust production in AGB stars, the age and metallicity gradients of the solar neighbourhood and structure within the Gould Belt. We close by discussing the potential impact of future Gaia data releases.

The kinematic signature of the Galactic warp inGaiaDR1

The mechanism responsible for the warp of our Galaxy, as well as its dynamical nature, continues to remain unknown. With the advent of high precision astrometry, new horizons have been opened for detecting the kinematics associated with the warp and constraining possible warp formation scenarios for the Milky Way. The aim of this contribution is to establish whether the first Gaia data release (DR1) shows significant evidence of the kinematic signature expected from a long-lived Galactic warp in the kinematics of distant OB stars. As the first paper in a series, we present our approach for analyzing the proper motions and apply it to the sub-sample of Hipparcos stars. We select a sample of 989 distant spectroscopically-identified OB stars from the New Reduction of Hipparcos, of which 758 are also in Gaia DR1, covering distances from 0.5 to 3 kpc from the Sun. We develop a model of the spatial distribution and kinematics of the OB stars from which we produce the probability distribution functions of the proper motions, with and without the systematic motions expected from a long-lived warp. A likelihood analysis is used to compare the expectations of the models with the observed proper motions from both Hipparcos and Gaia DR1. We find that the proper motions of the nearby OB stars are consistent with the signature of a warp, while those of the more distant stars (parallax<1 mas) are not. The kinematics of our sample of young OB stars suggests that systematic vertical motions in the disk cannot be explained by a simple model of a stable long-lived warp. The Galactic warp may either be a transient feature, or additional phenomena are acting on the gaseous component of the Milky Way, causing systematic vertical motions that are masking the expected warp signal. A larger and deeper sample of stars with Gaia astrometry will be needed to constrain the dynamical nature of the Galactic warp.

FIRST GAIA LOCAL GROUP DYNAMICS: MAGELLANIC CLOUDS PROPER MOTION AND ROTATION

ABSTRACT We use the Gaia data release 1 (DR1) to study the proper motion (PM) fields of the Large and Small Magellanic Clouds (LMC, SMC). This uses the Tycho-Gaia Astrometric Solution (TGAS) PMs for 29 Hipparcos stars in the LMC and 8 in the SMC. The LMC PM in the West and North directions is inferred to be , and the SMC PM . These results have similar accuracy and agree to within the uncertainties with existing Hubble Space Telescope (HST) PM measurements. Since TGAS uses different methods with different systematics, this provides an external validation of both data sets and their underlying approaches. Residual DR1 systematics may affect the TGAS results, but the HST agreement implies this must be below the random errors. Also in agreement with prior HST studies, the TGAS LMC PM field clearly shows the clockwise rotation of the disk, even though it takes the LMC disk in excess of 108 years to complete one revolution. The implied rotation curve amplitude for young LMC stars is consistent with that inferred from line of sight (LOS) velocity measurements. Comparison of the PM and LOS rotation curves implies a kinematic LMC distance modulus , consistent but not yet competitive with photometric methods. These first results from Gaia on the topic of Local Group dynamics provide an indication of how its future data releases will revolutionize this field.

GaiaData Release 1

At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. We summarize Gaia DR1 and provide illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release. Gaia DR1 consists of: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the Hipparcos and Tycho-2 catalogues and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set,consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of ~3000 Cepheid and RR Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas/yr for the proper motions. A systematic component of ~0.3 mas should be added to the parallax uncertainties. For the subset of ~94000 Hipparcos stars in the primary data set, the proper motions are much more precise at about 0.06 mas/yr. For the secondary astrometric data set, the typical uncertainty of the positions is ~10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to ~0.03 mag over the magnitude range 5 to 20.7. Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data.

Warm Debris Disks with WISE and HST

AbstractUsing 22 μm data from the Wide Field Infrared Survey Explorer (WISE), we have completed a sensitive all-sky survey for debris disks in Hipparcos and Tycho catalog stars within 120 pc. This warm excess emission traces material in the circumstellar region likely to host terrestrial planets. Several hundred previously unknown debris disk candidates were identified. We are currently performing follow-up observations to characterize the stars, companions, and circumstellar material in these systems with a variety of facilities including Keck, Herschel, and HST. Thirteen WISE debris disks have been observed to date using HST/STIS coronagraphy. Five of these disks have been detected in scattered light. One is a large and highly asymmetric edge-on disk which appears to be both warped and bifurcated.

Sensitive Identification of Nearby Debris Disks via Precise Calibration of WISE Data

AbstractUsing data from the WISE All-Sky Survey, we have found &gt;100 new infrared excess sources around main-sequence Hipparcos stars within 75 pc. Our empirical calibration of WISE photospheric colors and removal of non-trivial false-positive sources are responsible for the high confidence (&gt;99.5%) of detections, while our corrections to saturated W1 and W2 photometry have for the first time allowed us to search for new infrared excess sources around bright field stars in WISE. The careful calibration and filtering of the WISE data have allowed us to probe excess fluxes down to roughly 8% of the photospheric emission at 22μm around saturated stars in WISE. We expect that the increased sensitivity of our survey will not only aid in understanding the evolution of debris disks, but will also benefit future studies using WISE.

BAYESIAN AGES FOR EARLY-TYPE STARS FROM ISOCHRONES INCLUDING ROTATION, AND A POSSIBLE OLD AGE FOR THE HYADES

We combine recently computed models of stellar evolution using a new treatment of rotation with a Bayesian statistical framework to constrain the ages and other properties of early-type stars. We find good agreement for early-type stars and clusters with known young ages, including beta Pictoris, the Pleiades, and the Ursa Majoris Moving Group. However, we derive a substantially older age for the Hyades open cluster (750+/-100 Myr compared to 625+/-50 Myr). This older age results from both the increase in main-sequence lifetime with stellar rotation and from the fact that rotating models near the main-sequence turnoff are more luminous, overlapping with slightly more massive (and shorter-lived) nonrotating ones. Our method uses a large grid of nonrotating models to interpolate between a much sparser rotating grid, and also includes a detailed calculation of synthetic magnitudes as a function of orientation. We provide a web interface at www.bayesianstellarparameters.info where the results of our analysis may be downloaded for individual early-type (B-V<~0.25) Hipparcos stars. The web interface accepts user-supplied parameters for a Gaussian metallicity prior and returns posterior probability distributions on mass, age, and orientation.

Two estimates of the distance to the Galactic Centre

We use recently updated globular cluster distances to estimate the distance to the Galactic centre, finding 7.4 \pm 0.2|stat \pm 0.2|sys kpc from symmetry considerations. We recalibrate the red clump magnitude from Hipparcos stars, finding a skew distribution and a significant difference between peak and mean magnitudes. We find an estimate from stars in the periphery of the bulge using 2MASS, R0 = 7.5 \pm 0.3 kpc, in agreement with the figure from the halo centroid. We resolve discrepancies in the literature between estimates from the red clump. Our results are consistent with those found by different methodologies after taking systematic errors into account.

The local standard of rest from data on young objects with account for the Galactic spiral density wave

To estimate the peculiar velocity of the Sun with respect to the Local Standard of Rest (LSR), we used young objects in the Solar neighborhood with distance measurement errors within 10%-15%. These objects were the nearest Hipparcos stars of spectral classes O-B2.5, masers with trigonometric parallaxes measured by means of VLBI, and two samples of the youngest and middle-aged Cepheids. The most significant component of motion of all these stars is induced by the spiral density wave. As a result of using all these samples and taking into account the differential Galactic rotation, as well as the influence of the spiral density wave, we obtained the following components of the vector of the peculiar velocity of the Sun with respect to the LSR: (Uo,Vo,Wo)_{LSR}=(6.0,10.6,6.5)+\-(0.5,0.8,0.3) km/s. We have found that components of the Solar velocity are quite insensitive to errors of the distance Ro in a broad range of its values, from Ro=7.5 kpc to Ro=8.5 kpc, that affect the Galactic rotation curve parameters. In the same time, the Solar velocity components(Uo)_{LSR} and (Vo)_{LSR}$ are very sensitive to the Solar radial phase in the spiral density wave.

New distances to RAVE stars

Probability density functions are determined from new stellar parameters for the distance moduli of stars for which the RAdial Velocity Experiment (RAVE) has obtained spectra with S/N>=10. Single-Gaussian fits to the pdf in distance modulus suffice for roughly half the stars, with most of the other half having satisfactory two-Gaussian representations. As expected, early-type stars rarely require more than one Gaussian. The expectation value of distance is larger than the distance implied by the expectation of distance modulus; the latter is itself larger than the distance implied by the expectation value of the parallax. Our parallaxes of Hipparcos stars agree well with the values measured by Hipparcos, so the expectation of parallax is the most reliable distance indicator. The latter are improved by taking extinction into account. The effective temperature absolute-magnitude diagram of our stars is significantly improved when these pdfs are used to make the diagram. We use the method of kinematic corrections devised by Schoenrich, Binney & Asplund to check for systematic errors for general stars and confirm that the most reliable distance indicator is the expectation of parallax. For cool dwarfs and low-gravity giants <pi> tends to be larger than the true distance by up to 30 percent. The most satisfactory distances are for dwarfs hotter than 5500 K. We compare our distances to stars in 13 open clusters with cluster distances from the literature and find excellent agreement for the dwarfs and indications that we are over-estimating distances to giants, especially in young clusters.

YOUNG STARS NEAR EARTH: THE OCTANS-NEAR ASSOCIATION AND CASTOR MOVING GROUP

All cataloged stellar moving groups and associations with ages <100 Myr and within 100 pc of Earth have Galactic space motions (UVW) situated in a "good box" with dimensions ~20 km/s on a side. Torres et al. defined the Octans Association as a group of 15 stars with age "20 Myr?" and located ~140 pc from Earth, but with average V space velocity -3.6 km/s that is well outside of the good box. We present a list of 14 Hipparcos star systems within 100 pc of Earth that we call "Octans-Near"; these systems have UVW similar to those of the much more distant Octans Association. The Octans-Near stars have apparent ages between about 30 and 100 Myr and their relationship to the Octans Association stars is unclear. Six additional star systems have UVW similar to those of Octans-Near stars and likely ages <200 Myr. These six systems include the late-type binary star EQ Peg -- 6.2 pc from Earth with likely age <100 Myr and thus likely to be the nearest known pre-main sequence star system. The UVW of stars in a previously proposed ~200 Myr old Castor moving group are not too dissimilar from the UVW of Octans-Near stars. However, stars in the Castor group -- if it exists at all -- are mostly substantially older than 200 Myr and thus generally can readily be distinguished from the much younger Octans-Near stars.

Calibration of RAVE distances to a large sample of Hipparcos stars

A magnitude-limited population of 18 808 Hipparcos stars is used to calibrate distances for 52 794 RAdial Velocity Experiment (RAVE) stars, including dwarfs, giants and pre-main-sequence stars. I give treatments for a number of types of bias affecting calculation, including bias from the non-linear relationship between the quantity of interest (e.g., distance or distance modulus) and the measured quantity (parallax or visual magnitude), the Lutz–Kelker bias and bias due to variation in density of the stellar population. The use of a magnitude bound minimizes the Malmquist and the Lutz–Kelker bias, and avoids measurement bias resulting from the greater accuracy of Hipparcos parallaxes for brighter stars. The calibration is applicable to stars in 2MASS when there is some way to determine stellar class with reasonable confidence. For RAVE this is possible for hot dwarfs and using log g. The accuracy of the calibration is tested against Hipparcos stars with better than 2 per cent parallax errors, and by comparison of the RAVE velocity distribution with that of Hipparcos, and is found to improve upon previous estimates of luminosity distance. An estimate of the local standard of rest from RAVE data, (U0, V0, W0) = (14.9 ± 1.7, 15.3 ± 0.4, 6.9 ± 0.1) km s−1, shows excellent agreement with the current best estimate from extended Hipparcos compilation. The RAVE velocity distribution confirms the alignment of stellar motions with spiral structure.