This three-year period has seen considerable activity in the Commission, with a wide range of applications of radial velocities as well as a significant push toward higher precision. The latter has been driven in large part by the exciting research on extrasolar planets. This field is now on the verge of detecting Earth-mass bodies around nearby stars, as demonstrated by recent work summarized below, and radial velocities continue to play a central role.

Bioastronomy: Search for Extraterrestrial Life was established as Commission 51 of the IAU in 1982. The objectives of the commission included: the search for planets around other stars; the search for radio transmissions, intentional or unintentional, of extraterrestrial origin; the search for biologically relevant interstellar molecules and the study of their formation processes; detection methods for potential spectroscopic evidence of biological activity; the coordination of efforts in all these areas at the international level and the establishment of collaborative programs with other international scientific societies with related interests. In 2006, Commission 51 was renamed simply Bioastronomy at the IAU General Assembly in Prague, and approved for the next six years, the default extension for an IAU Commission.

Commission 22 is part of Division III on Planetary System Sciences of the International Astronomical Union. Members of Commission 22 are professional scientists studying bodies in the Solar System smaller than asteroids and comets, and their interactions with planets. The main subjects of interest are meteors, meteoroids, meteoroid streams, interplanetary dust particles, and also zodiacal cloud, meteor trains, meteorites, tektites, etc.

The IAU Commission 46 Program Group International Schools for Young Astronomers (ISYA) was created in 1967 (Gerbaldi 2008). During the period 2006 till August 2008 two ISYAs took place, one in Malaysia and a second one in Turkey.

The Working Group on Binary and Multiple System Nomenclature was formed within Commission 26 following Special Session 3 held during the 2003 Sydney General Assembly. Its purpose is to create the Washington Multiplicity Catalog, a comprehensive database first introduced at a multi-commission meeting at the IAU XXIV General Assembly in Manchester, 2000. Data are being compiled from the US Naval Observatory visual binary catalogs and supplemented with binary and multiple star information from other sources to include but not limited to spectroscopy, photometry, eclipsing and interacting system, as well as extra-solar planets and substellar companions. The goal being creation of a comprehensive hierarchical database and to reduce confusion from multiple nomenclature schemes used by disparate techniques.

Two meetings of interest to close binaries took place during the reporting period: A full day session on short-period binary stars – mostly CV's – (Milone et al. 2008) during the 2006 AAS Spring meeting in Calgary and the very broadly designed IAU Symposium No. 240 on Binary Stars as Critical Tools and Tests in Contemporary Astrophysics in Prague, 2006, with many papers on close binaries [Hartkopf et al. 2007]. In addition, the book by Eggleton (2006), which is a comprehensive summary of evolutionary processes in binary and multiple stars, was published.

A total of 701 comets received names between July 2005 and June 2008. Comets observed only from the SOHO and STEREO missions, as well as further comets recognized from the long-defunct SOLWIND satellite, accounted for 520 of these names.

The Supernova Working Group was re-established at the IAU XXV General Assembly in Sydney, 21 July 2003, sponsored by Commissions 28 (Galaxies) and 47 (Cosmology). Here we report on some of its activities since 2005.

Commission 12 encompasses investigations on the internal structure and dynamics of the Sun, mostly accessible through the techniques of local and global helioseismology, the quiet solar atmosphere, solar radiation and its variability, and the nature of relatively stable magnetic structures like sunspots, faculae and the magnetic network. A revision of the progress made in these fields is presented. For some specific topics, the review has counted with the help of experts outside the Commission Organizing Committee that are leading and/or have recently presented relevant works in the respective fields. In this cases the contributor's name is given in parenthesis.

JPL planetary ephemeris development has been very active assimilating measurements from current planetary missions and supporting future missions. The NASA Mars Science Laboratory (MSL) mission with launch in 2009 requires knowledge of the Earth and Mars ephemerides with 30m accuracy. By comparison, the accuracy of the Mars ephemeris in the widely used DE405 ephemeris was about 3 km. Meeting the MSL needs requires an ongoing program of range and very-long baseline interferometry measurements of Mars orbiting spacecraft. The JPL ephemeris DE421 was released three months before the landing of the Phoenix mission on Mars, and has met the 300m requirement. Continued measurements are planned to support the MSL landing.

The Working Group Archives deals with all aspects of the identification and preservation of astronomical archives. In 2009 the IAU will celebrate its 90th anniversary, and on this occasion the WG is taking action toward preserving the archival materials related with the history of IAU. An institution must keep memory of its own past and, as the centenary of IAU is approaching, for the 2006-2009 triennium the WG Archives has started evaluating the archival collections related to the establishment of IAU, in order to check their extent and the current conditions of preservation and conservation of such documents.

The IAU/IAG Working Group on Cartographic Coordinates & Rotational Elements published its (2006) triennial report containing current recommendations for models for solar system bodies (Seidelmann et al. 2007). P. Kenneth Seidelmann stepped down as chairperson and B. A. Archinal was elected chairperson at the Working Group business meeting that took place at the IAU XXVI General Assembly in Prague in 2006.

As we have noted before, the WG-IR was created following a Joint Commission Meeting at the IAU General Assembly in Baltimore in 1988, a meeting that provided both diagnosis and prescription for the perceived ailments of infrared photometry at the time. The results were summarized in Milone (1989). The challenges involve how to explain the failure to systematically achieve the milli-magnitude precision expected of infrared photometry and an apparent 3% limit on system transformability. The proposed solution was to re-define the broadband Johnson system, the passbands of which had proven so unsatisfactory that over time effectively different systems proliferated although bearing the same JHKLMNQ designations; the new system needed to be better positioned and centered in the atmospheric windows of the Earth's atmosphere, and the variable water vapour content of the atmosphere needed to be measured in real time to better correct for atmospheric extinction.

IAU Division IV organizes astronomers studying the characteristics, interior and atmospheric structure, and evolution of stars of all masses, ages, and chemical compositions.

The main activity of the WG on Abundances in Red Giants has been to propose a JD for the IAU GA in 2009. The increasing evidence for distinct populations within globular clusters is leading to the view that there is a continuum between globular clusters and the smallest of the galaxies. Our JD was designed to investigate this link. However, our JD was incorporated into IAU Symposium No. 266 Star Clusters: Basic Building Blocks throughout Time and Space for the IAU XXVII in Rio de Janeiro, 2009. We will be responsible for organising one session in the Symposium to cover the agenda put forward in our JD proposal.

Division XI connects astronomers using space techniques or particle detectors for an extremely large range of investigations, from in-situ studies of bodies in the solar system to orbiting observatories studying the Universe in wavelengths ranging from radio waves to γ-rays, to underground detectors for cosmic neutrino radiation.

The interplay of the disc and the dark halo resonances governs the secular evolution of disc galaxies, and the properties of their bar component (Athanassoula 2002). Martinez-Valpuesta et al. (2006), Ceverino & Klypin (2007) and Athanassoula (2007b) confirm and extend this work. Ceverino & Klypin (2007) calculate the orbital frequencies of each particle over the whole temporal evolution, and thus find much broader frequency peaks. In all cases, it is the same resonances that come into play, and, as in Athanassoula 2002, the angular momentum is emitted by near-resonant material in the bar region and absorbed by near-resonant material in the halo and the outer disc. The relative importance of each resonance, however, varies from one case to another. Furthermore, the second and third of the above mentioned studies examine the location of resonant orbits in configuration space and find compatible results.

Division VII gathers astronomers studying the diffuse matter in space between stars, ranging from primordial intergalactic clouds, via dust and neutral and ionized gas in galaxies, to the densest molecular clouds and the processes by which stars are formed.

Division III's activities focus on a broad range of astronomical research on bodies in the solar system (excluding the Sun), on extrasolar planets, and on the search for life in the Universe.

The Working Group Galactic Center was created following a Business Meeting meeting of Division VII Galactic Systems, held with the concurrence of Division VIII Galaxies and the Universe, at the IAU XXVI General Assembly in Prague, 2006. The objective of the meeting was to highlight both recent progress on understanding the Galactic Center as well as to illustrate the way in which the center of the Milky Way Galaxy serves as a laboratory for understanding other galactic nuclei.