PRESIDENT: A.A. Tokovinin
VICE-PRESIDENT: B. Nordström
ORGANIZING COMMITTEE:
D. Dravins,
H. Levato,
T. Mazeh,
N. Morell,
H. Quintana,
M.A. Smith,
L. Szabados,
S. Udry
Commission 30 has 129 members and consultants in 28 countries who are active in the area of radial velocities (RVs). The work of the commission covers a wide range of topics all of which concern the application of the Doppler effect to astronomical objects, including galaxies and the interstellar medium as well as stars, and in all wavelength ranges of the electromagnetic spectrum. Although the commission focusses mainly on stellar and galaxy radial velocities, it is noted that stellar rotation, spectroscopic binaries, extrasolar planets, pulsating stars, asteroseismology and turbulence in stellar atmospheres are also included.
The reader is invited to visit the WEB page of Commission 30 at http://www.ctio.noao.edu/science/iauc30/iauc30.html for detailed information on Commission and its WGs.
Very high measuring precisions, differential lineshifts measured in the same star, and astrometric determinations of radial motion, have required the concept of "radial velocity" to be more stringently defined, in order to permit comparisons between various measurements on accuracy levels of m/s. Relativistic effects, measurements being made inside gravitational fields, and alternative choices of coordinate frames, cause the naive concept of RV being equal to the time derivative of distance, to become ambiguous at accuracy levels around 100 m/s. Following an e-mail discussion in the community during a couple of years, two resolutions for the stringent definition of spectroscopic and astrometric RVs were adopted at the IAU XXIVth General Assembly in Manchester (Rickman 2002, IAU Inf. Bull., 91, 50), while their implications are discussed by Lindegren & Dravins 2002, A&A, submitted.
For precise spectroscopic measurements, the desired result is the barycentric radial-velocity measure, czB, the apparent Doppler shift after correcting for gravitational effects caused by solar-system objects, and effects by the observer's displacement and motion relative to the solar-system barycenter. To first order this coincides with the classical concept of RV and for modest accuracies (0.5 km/s, say), the new definition implies no change of existing procedures. However, the future use of czB will permit to exploit high-accuracy measurements for new classes of astrophysical tasks.
The definitions avoid any discussion of what the "true" RV would be, and a main point is that highly precise observations should be published (also) without the observer first trying to "calibrate" them against "standard" objects. Any subsequent interpretation of observed wavelength shifts in terms of the object's radial and transverse motion and other effects should be made separately. Since the uncertainties in any such modeling are much greater than those now reachable for the wavelength shifts themselves, precise observational data may become corrupted by applying model-dependent "corrections", thus precluding their use for possible more sophisticated analyses in the future. An example of such effects is the detection of small differences in the apparent RVs of different classes of photospheric lines due to convection (Allende Prieto et al. 2002 2002ApJ...567..544A).
The three years covered by this report has seen the coming of age of a new generation of RV surveys of galaxies. These are characterized by one or two orders of magnitude increase in the number of redshifts obtained over previous ones, reaching over 105 galaxies measured. The two most emblematic such massive surveys, now fully underway, are the Sloan Digital Sky Survey (SDSS) and the 2dF Galaxy Redshift Survey (2dFGRS). At present the SDSS has reached a number of new galaxy redshifts of order 2.5 105 (4 105 including all objects), being at about 1/3 of its completion target, and the 2dFGRS has reached 2.2 105,close to its target.
New research fields are being opened with these and future extensive surveys. Now it will be possible to quantitatively study hundreds of thousands of galaxies and to obtain high precision statistical results, from those datasets or from comparison with similar databases at other wavelengths. For the first time, optical data are providing strong constraints on cosmologies. Gone are the days of surveys done by a couple of astronomers and a few telescope nights of observations. Modern surveys require dedicated telescopes and/or spectrographs, years of continuous observations, teams of astronomers (often located in several countries) and substantial research funds.
| Survey | N, 103 | URL, http:// |
| SDSS | 750 | www.astro.princeton.edu/PBOOK/welcome.html |
| 2dFGRS | 250 | www.mso.anu.edu.au/2dFGRS/Public/Survey |
| 2MASS RS | 150 | pegasus.phast.umass.edu |
| 6df | www.mso.anu.edu.au/colless/6dF | |
| DEEP | 1.1 | deep.ucolick.org |
| NOAO deep-wide | www.archive.noao.edu/ndwfs | |
| PSCz | 15 | www-astro.physics.ox.ac.uk/wjs/pscz.html |
| LCRS | 26.418 | manaslu.astro.utoronto.ca/lin/lcrs.html |
| Durham/UKST | 2.5 | star-www.dur.ac.uk/fhoyle/ukst.html |
Other important surveys, though less massive, have been completed or are underway (Table 1). Typically they are producing thousands of galaxy redshifts. As is now customary, all these projects have Web pages, describing the survey parameters and characteristics, sometimes catalogues and/or data are available on-line, complete documentation, including all the papers dealing with the subject and other relevant information for the interested users, is also available. For this reason here we only point the reader to these sources. Among these surveys are: the all-sky NIR selected 2MASS Redshift Survey, the NIR selected 6dF Survey carried out with FLAIR and related to the above, the DEEP - Deep Extragalactic Evolutionary Probe done with Keck and HST, the starting NOAO deep-wide survey for objects at z>1, and several surveys now completed, such as the PSCz Redshift Survey, providing redshifts of IRAS galaxies, the LCRS - Las Campanas Redshift Survey, the CNOC and ENACS cluster surveys, the CFRS, the Durham/UKST survey. We should also mention the Shapley supercluster survey that now reached some 6500 galaxy redshifts (Quintana et al. 2000AJ....120..511Q ), the Southern Abell cluster survey (Muriel et al., in press) with over 6000 velocities in 40 clusters. Furthermore, there are several galaxy redshift efforts in the HDF-S and other pencil beam imaging surveys. In the next few years to come we will see the emergence of large surveys done with multiobject (multislit and fibers) spectrographs at 8 m-class telescopes, e.g. with VIMOS at VLT and with GMOS at Gemini.
The Milky Way is the galaxy for which the most detailed dynamical information can be obtained, from distances, proper motions, and radial velocities of well-defined populations of stars. Because the properties of the Galaxy itself rather than its individual constituents are the subject of study, new surveys and catalogues of many galactic stars are the key resource in Galactic research.
The main such large new radial-velocity studies in the triennium are listed below, even though the main motivation for some of the surveys have been the study of certain types of objects such as extrasolar planet hosts or pulsating stars.
Galactic centre: Near the centre of the Milky Way, Ghez et al. (2000Natur.407..349G ) have measured accelerations for several stars and found strong evidence for a supermassive black hole.
The thin and thick disks: A sample of 39 photometrically selected, very red M dwarfs was studied by Reid et al. (2000MNRAS.316..827R) from Keck/HIRES spectra. The velocity dispersions suggest that this newly-discovered ultra-cool population of M dwarfs is young.
Gilmore et al. (2002ApJ...574L..39G ) redetermined the rotation of the thick disk from radial velocities of some 2000 F/G stars obtained with the 2dF multi-fibre instrument. They find a much slower net rotation (100 km/s) than expected and conclude that a single major merger event took place in the Galaxy some 10-12 Gyr ago.
Space motions for 39 metal-poor giant stars observed by Beers et al. (2002AJ....124..931B ) indicate that the metal-weak thick disk extends to metallicities below [Fe/H] = -1.6.
Population II stars: First radial velocities for a sample of 114 halo stars, including 5 probable binaries, were published by Sperauskas & Bartkevicius (2002AN....323..139S ). A large RV survey of halo stars conducted at CfA produced many spectroscopic orbits (Latham et al. 2002AJ....124.1144L ; Goldberg et al. 2002AJ....124.1132G ).
General: As part of a major effort to search for small-scale velocity variables and potential planet hosts, Nidever et al. (2002ApJS..141..503N ) studied radial velocities for 889 FGKM stars. With almost 90 % of the stars having radial velocity variations of less than 200 m/s, it is suggested that they might form the basis for a future set of standard stars.
A catalogue of mean radial velocities for 20574 stars was published by Barbier-Brossat and Figon (2000A&AS..142..217B ) and available from the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5). The bibliographic catalogue of stellar radial velocities 1991-1994 (Malaroda et al. 2000A&AS..144....1M ) contains 13359 entries for stars in the Milky Way and the Magellanic Clouds. This catalogue is also available from the CDS (130.79.128.5).
This field experienced enormous progress, such as the availability of
high resolution spectroscopy of relatively faint stars, allowing the
study of low-mass cluster members, like PMS and brown dwarfs, the
application of high quality proper motions to the determination of
astrometric radial velocities and the derivation of radial velocities
from IR spectroscopy.
Open clusters:
Radial velocities for PMS candidates have been obtained in IC 4996 (Delgado et al., 1999AJ....118.1759D ), NGC 2264 (Soderblom et al., 1999AJ....118.1301S ), near the center of the lambda Orionis star-forming region (Dolan & Mathieu, 1999AJ....118.2409D ), in the sigma Orionis cluster (Zapatero Osorio et al., 2002A&A...384..937Z ). Most of these studies relie in the lithium 6708 Å absorption as diagnostic of youth. Also Alcalá et al. (2000A&A...353..186A ) present high resolution spectroscopy of ROSAT low-mass lithium-rich probable PMS stars in Orion. Chromospheric activity, lithium abundance and radial velocities of 14 single late-type stars possible members of young moving groups are analysed by Montes et al. (2001A&A...379..976M ).
Barrado y Navascués et al. (2001ApJ...549..452B) reported WIYN/HYDRA spectroscopy of 76 candidate members in the young open cluster M35 providing radial velocities, lithium abundances and rotational velocities.
89 M dwarf members of the Pleiades and Hyades were investigated by Terndrup et al. ( 2000AJ....119.1303T). In a high resolution spectroscopic study of 51 M dwards in the Hyades cluster, Reid & Mahoney (2000MNRAS.316..827R) identified a binary with a candidate brown dwarf companion. A spectroscopic orbit was computed by Basri & Martin (1999AJ....118.2460B) for another brown dwarf binary, member of the Pleiades.
Radial velocities of low mass probable members have been presented for IC 2391 by Barrado y Navascués et al. (1999ApJ...522L..53B), for IC2391 and IC2602 by Randich et al. (2001A&A...372..862R) and for the alpha Per cluster by Stauffer et al. (1999ApJ...527..219S).
Meibom et al. (2002A&A...386..187M) present multiple-epoch radial-velocity observations for 104 stars in the intermediate-age open cluster IC 4651.
The first astrometric and spectroscopic investigation of the old cluster NGC 2355, in the outer part of the galactic disk, was performed by Soubiran et al. (2000A&A...357..484S).
Platais et al. (2001AJ....122.1486P) found that NGC 2451A is undoubtedly a young sparse open cluster, obtaining radial velocities for 34 likely cluster members.
González & Lapasset presented echelle spectroscopic observations of bright probable members of NGC 2516 (2000AJ....119.2296G), NGC 3114 (2001AJ....121.2657G) and NGC 3532 (2002AJ....123.3318G). García & Mermilliod (2001A&A...368..122G) obtained new radial velocities for 37 OB stars in NGC 6231 giving improved orbital elements for binarires.
Glushkova et al. (2000yCat..90250115G) presented 191 individual measurements of radial velocities made with CORAVEL-type spectrometer for 60 stars in NGC 6811.
CORAVEL observations were published by Mermilliod & Mayor (1999A&A...352..479M, 103 F5-K0 stars in Praesepe), and Debernardi et al. (2000A&A...354..881D, Am stars in the Hyades and Praesepe). Radial velocities in Praesepe and Coma Berenices were also obtained by Abt & Willmarth (1999ApJ...521..682A) Those studies present orbital elements for spectroscopic binaries. Coma Berenices has also been studied by Ford et al. (2001A&A...369..871F, radial and rotational velocities and lithium abundances for F,G and K stars) and García López et al. (2000A&A...363..958G, optical investigation of 12 ROSAT discovered candidate members).
Mermilliod et al. ( 2001A&A...375...30M)
present accurate radial velocities and photoelectric UBV photometry for
red-giant candidates in the intermediate-age open
clusters NGC 2324, 2818, 3960 and 6259. They analysed membership
and spectroscopic binaries.
Astrometric radial velocities:
The Lund Observatory group, continued the work on
astrometric radial velocities (precision around 1 km/s),
for stars in nearby open clusters or associations for which
accurate proper motions and trigonometric parallaxes are
available (Dravins et al. 1999A&A...348.1040D,
Lindegren et al., 2000A&A...356.1119L,
Madsen et al., 2002A&A...381..446M).
Open clusters in LMC:
Dieball et al. (2000A&A...358..144D)
obtained ESO-NTT MOS observations of 22 stars in or near the clusters
SL 353 & SL 349. The measured radial velocities
for individual stars (from the CaII triplet near 8500Å)
seem to confirm a common origin for both clusters.
Multislit spectroscopy of stars in the ionising cluster of 30 Dor
presented by Bosch et al. (2001A&A...380..137B)
gives radial velocities for 55 stars.
The high observed velocity disperion (~35 km/s)
compared with numerical simulations suggests a large number of
binaries in the observed sample.
Massey et al. (2002ApJ...565..982M), obtained
the first radial velocity and photometric study of
4 massive early O-type double-lined binaries in the R136 cluster.
The Galactic Center open cluster:
Moderate resolution near-IR spectroscopy
(using CFHT, ESO and Keck facilities)
yields the first radial velocity determinations
for individual stars in the galactic center open cluster
Genzel et al. (2000MNRAS.317..348G), Paumard et al. (2001A&A...366..466P),
Gezari et al. (2002ApJ...576..790G).
Comparison with proper motions are consistent with a spherical
star cluster around Sgr A.
A bibliographic database for stars in open clusters
from which most published data can be retrieved
is maintained by J.-C. Mermilliod:
http://obswww.unige.ch/webda/
Globular clusters
Côté (1999AJ....118..406C) used HIRES on the Keck I to measure the first radial velocities for stars belonging to 11 heavily reddened globular clusters in the direction of the inner Galaxy.
In order to investigate membership in the clusters, Coelho et al. (2001A&A...376..136C) measured radial velocities and atmospheric parameters of 23 stars towards the bulge globular clusters NGC 6528 and NGC 6553 and Idiart et al. (2002A&A...381..472I) obtained radial velocities and metallicities of 17 stars in Terzan 1.
Gebhardt et al. (2000AJ....119.1268G) presented radial velocities in the central region of M15 obtained with CFHT Fabry-Perot spectroscopy plus adaptive optics.
The first radial velocites for six giant stars in the Pyxis globular cluster, proposed to be a LMC cluster captured by the Milky Way, were obtained by Palma et al. (2000PASP..112.1305P).
Radial velocities for 303 giant stars in the globular clusters M3, M13, M15, and M92 were presented by Soderberg et al. (1999PASP..111.1233S).
Moehler et al. (2000A&A...361..937M) presented atmospheric parameters and radial velocities for twelve candidate blue HB stars in 47 Tuc and NGC 362.
The systematic RV search for spectroscopic binaries (SBs) within a large complete sample of more than 1400 high-proper-motion stars has been finally completed (Latham et al. 2002AJ....124.1144L ; Goldberg et al. 2002AJ....124.1132G ), yielding 171 singled-lined binaries (SB1) and 34 double-lined ones (SB2). This rich sample of binaries increased dramatically our knowledge of the characteristics of the SB population with K-type primaries. The Geneva group extended the Duquennoy and Mayor G-type study to K stars (Mayor et al. 2001IAUS..200...45M ). In the meantime, the Geneva and the CfA teams (together with Tel Aviv research group) are monitoring a large sample of >3000 nearby G stars. Although this effort did not yield any new publication in the last three years (see Udry et al. 1998, ASP Conf. Ser. 154, 2148), this survey, when completed, will increase our information about SB with G-type primaries.
A pioneering work is done at the Geneva Observatory to determine the spectroscopic orbits of early-type stars with Elodie and Coralie, their high-precision high-resolution speedometers. They even succeeded to find an orbit of a {delta} Scuti A star, whose orbital variability was masked by the stellar pulsation (Carrier et al. 2002A&A...390.1027C ). This work has the potential of studying barely explored domains of the parameter space of SBs.
In the last three years, dedicated observations to detect secondary spectra and derive their RVs in known SB1s, thus turning them into SB2s, started to yield some interesting results. It has been shown that observations in the infrared (Mazeh et al. 2002ApJ...564.1007) could detect faint secondaries, specially if the binary is in its PMS phase (Prato et al. 2002ApJ...569..863P ).
We have seen recently many studies that combine RV orbits with astrometric/interferometric/photometric data that produce new results on stellar masses. Apart from a classical combination of spectroscopy and photometry for eclipsing SB2s (e.g. Torres et al. 2000AJ....120.3226T; Torres & Ribas 2002ApJ...567.1140T), two approaches are used:
1. Derivation of the secondary masses (or at least upper limits for them) of SB1s, by combining astrometric data from the Hipparcos satellite with RV measurements, when the primary masses are estimated from their spectra (Halbwachs et al. 2000A&A...355..581H; Pourbaix & Arenou 2001A&A...372..935P ; Pourbaix 2001A&A...369L..22P; Zucker & Mazeh 2001ApJ...562..549Z). These works corroborated the suggestion that the populations of planets and stellar secondaries are separated by their masses with the "brown dwarf desert". More results are expected from the next generation of astrometric satellites.
2. Derivation of the masses of the two components of SB2s by combining RVs with astrometric/interferometric data (Torres 2002AJ....124.1716T), specially for PMS binaries (Steffen et al. 2001AJ....122..997S ). A new mass-luminosity relation at the bottom of the main-sequence is derived (e.g. Delfosse et al. 2000A&A...364..217D ), leading to an interesting confrontation with stellar models.
In the last 3 years, the p-mode oscillations in solar-type stars other than Sun have finally been detected, opening a new field of astroseismology that provides direct information on stellar interior structure. After attempts to use various photometric and spectroscopic techniques, a breakthrough has occurred with precise RV measurements clearly detecting many individual acoustic modes in several ordinary stars. The observations, requiring precisions on the m/s level, were made with spectrometers developed primarily for exoplanet searches.
Possibly, the first such significant detection was for Procyon (F5 IV-V) (Martic et al. 1999A&A...351..993M), although the power spectrum was found to be less regular than solar. The p-mode oscillation spectrum in {beta} Hyi (G2 IV) was detected with different instruments by Bedding et al. (2001ApJ...549L.105B) and Carrier et al. (2001A&A...378..142C). Typical frequencies are around 1 mHz (periods ~15 min, three times longer than in the Sun), reflect the larger size and lower surface gravity in this subgiant. Analogous oscillations in the solar near-twin {alpha} Cen A (G2 V) were seen by Bouchy & Carrier (2002A&A...390..205B).
The precise determination of oscillation frequencies requires long observation periods (weeks) and high instrumental stability, especially challenging for the long oscillation periods in giant stars. For {xi} Hya (G7 III), a month-long observing campaign was needed to map out oscillation periods of typically 3 hours (ESO press release, 10/02 2002).
Extensive work on other, "classical" types of pulsating variables done in the past triennium is briefly covered below.
Cepheids. The most extensive observing effort on RVs of cepheids (about 1500 RVs) during the recent 3 years was that of the Moscow team (N.A. Gorynya et al.). These data have been analyzed for detection of new binaries and for properties of the pulsators, with the use of the Fourier-decomposition techniques (P. Moskalik, Warsaw). Pont et al. (2001A&A...376..892P) carried out morphological study of RV curves of outer-disk Cepheids based on new data; no effect of metal abundance on RV curves was found.
Bersier (2002ApJS..140..465B) revealed or confirmed the spectroscopic binary nature of U Car, XX Car, T Cru, WZ Sgr, and SY Nor, while Evans (2000AJ....119.3050E) determined a 5-yr orbit for V1334 Cyg form 30 years of data. The precise RV measurements of Polaris - a Cepheid also belonging to an SB system - show additional intrinsic variation superimposed on the pulsational and orbital effects (Hatzes & Cochran, 2000AJ....120..979H) whose origin has not been clarified yet. It is also important that the pulsational amplitude of Polaris stopped decreasing.
Gamma Doradus type variables. From the newly defined type of pulsating variables, HR 8799 was studied most thoroughly (Zerbi et al. 1999MNRAS.303..275Z): the multi-site photometric campaign was supplemented with a set of RV data.
Mira type and other long-period variables. Alvarez et al. (2001A&A...379..305A) performed envelope tomography for long-period variable stars. Scholz & Wood (2000A&A...362.1065S) calculated model atmospheres for Miras and concluded that they pulsate in the first overtone mode.
The period covered by this report has seen tremendous developments in the exoplanet domain. Mostly resulting from the increase in the baseline of the RV data and the enlargement of the survey samples, the planet list has grown from a merely 20 planets to now more than 100. The variety of planetary characteristics observed with the first candidates is developing further. We have: longer-period candidates, a large planetary mass range from sub-saturnian (Marcy et al. 2000ApJ...536L..43M; Pepe et al. 2002A&A...388..632P) up to masses above 10MJup, and candidates with very high eccentricities up to e=0.92 (Naef et al. 2001A&A...375L..27N). With longer period objects becoming detectable, some planets are now found to resemble our Solar System giant planets. The number of multi-planetary systems reached about 11 today. Several of them are found in resonant configurations like e.g. period ratios of 2:1. In such systems, planet-planet interactions bring further information on the orbital inclinations. Planets orbiting components of wide and spectroscopic binaries have been also detected.
This strong increase in the number of planetary candidates has boosted various new studies that are opening a complete new window into the mechanisms of planetary formation and evolution. The "magic" number of 100, more than having a philosophical meaning, means that we are now able to do significant statistical analyses of the exoplanet properties. These have permitted to confirm former suggested trends, as well as to unveil new ones. The distribution of the planetary mass is found to be steeply rising towards the low mass regime, even when we correct for the orbital inclination effects (Jorissen et al. 2001A&A...379..992J; Zucker & Mazeh 2001ApJ...562.1038Z). The maximum mass of a planet is estimated to be around 10MJup, a limit that does not have anything to do with the deuterium burning limit of 13 MJup.
The study of the orbital period distribution has shown the importance of considering migration processes to explain the observed current configuration of the planetary systems (piling-up of planets with periods around 3 days, rise of the number of massive planets with distance). Also a paucity of high mass companions orbiting in short period trajectories has been pointed out (Zucker & Mazeh 2002ApJ...568L.113, Udry et al. 2002A&A...390..267U). These results bring strong constraints for the migration mechanisms.
Further information comes from the study of the planet hosts themselves. They are found to be particularly metal rich when compared to average field dwarfs (Gonzalez et al. 2001AJ....121..432G; Santos et al. 2001A&A...373.1019S). This tendency, of probable primordial origin, indicates that planet formation is strongly dependent of the metallicity of the cloud of gas and dust that gave birth to the star and planetary system. Some possible evidences of the infall of planetary material (or even planets) were however discovered in HD82943 in the form of an anomalous lithium isotopic ratio (Israelian et al. 2001Natur.411..163I).
The exoplanet research was not restricted to the RVs. The most prominent result is the detection of the transit of a giant planet in front of the star HD209458 (Charbonneau et al. 2000ApJ...529L..45C; Henry et al. 2000ApJ...529L..41H). This detection not only represents an independent confirmation of the nature of the discovered body, but also provides planetary physical properties, like its mass, radius, or mean density. Subsequent studies of this system have permitted to show that the planet around HD209458 is orbiting in the plane of the stellar equator (Queloz et al. 2000A&A...359L..13Q). Furthermore, recent spectroscopic studies have permitted to unveil some details about the composition of the atmosphere of the planet itself (Charbonneau et al. 2002ApJ...568..377C). Although RV methods provide for the moment the more efficient way to search for exoplanets, wide-field photometric planetary transit surveys may open a new era, revealing thousands of transits in a near future.
Members: S. Udry (chair), R. Stefanik, and F. Fekel. The tedious work on RV standards was continued with no new results as yet.
Members: H. Levato (chair) and S. Malaroda, with technical support from M. Grosso, S. Galliani, and A. Rodas. The WG has updated the Bibliographic Catalogue of Radial Velocities during this period at a rate of a new update each semester. At the time of this writing the update up to December 31 2001 has been published and the version 2002.5 will be available before the end of October 2002 at the WEB site www.casleo.gov.ar and at the CDS. The last published version has almost 45000 entries, duplicating this number over the past 5 years.
Members: A. Tokovinin (chair), A. Batten, F. Fekel, W. Hartkopf, D. Latham, H. Levato, B. Mason, N. Morell, D. Pourbaix, S. Udry. This WG was created in 2000 to compile the 9th catalogue of orbits of spectroscopic binaries (SB9), superseding the SB8 of Batten et al. (1989coes.book.....B). SB9 exists in electronic format only; unlike SB8, it contains also individual radial velocities (at least for new orbits where they are available) and is continuously updatable.
The SB9 web site sb9.astro.ulb.ac.be was officially released in summer 2001. It was implemented by D. Pourbaix and provides convenient interface with object search capabilities, output of all data and graphs. Since November 13, 2001, there were 1931 queries to SB9 from 154 different IP addresses, showing a high degree of community interest. SB9 is linked to the web pages of IAU Commissions 30 and 26 as well as to the Besançon database on binary stars, http://bdb.obs-besancon.fr.
As of October 1, 2002, SB9 contained 1707 systems (1469 in SB8) and 1756 orbits (1469 in SB8). A total of 70 papers were added, but most of them not by the WG members, as was planned initially. We still have a list of 304 identified papers whose orbits need to be entered.
A.A. Tokovinin
President of the Commission
Last modified: October 5, 2002 A. Tokovinin