Radar is a uniquely powerful source of information about near-Earth asteroid (NEA) physical properties and orbits. This review consists largely of edited excerpts from Ostro and Giorgini (2004).

Classical theories of turbulence do not describe accurately inertial range scaling laws in turbulent convection and notably fail to model the shape of the turbulent spectrum of solar photospheric convection. To understand these discrepancies, a detailed study of scale-by-scale budgets in turbulent Rayleigh-Bénard convection is presented, with particular emphasis placed on anisotropy and inhomogeneity. A generalized Kolmogorov equation applying to convection is derived and its various terms are computed using numerical simulations of turbulent Boussinesq convection. The analysis of the isotropic part of the equation shows that the third-order velocity structure function is significantly affected by buoyancy forcing and large-scale inhomogeneities. Anisotropic contributions to this equation are also shown to be comparable to their isotropic counterpart at moderate to large scales. Implications of these results for convection in the solar photosphere, mesogranulation and supergranulation are discussed.

We are studying the molecular clouds in the region around G333.6-0.2 in a number of 3-mm transitions from different molecular species, to probe, among other things, the turbulent properties. The observations are being made by on-the-fly mapping with the 22-m diameter single-dish Mopra radio telescope. See Bains et al. (2006) and Cunningham et al. (2006 in these proceedings) for more details. During 2004 and 2005 we obtained 13 CO (1 – 0), C18O, CS (2 – 1) and C34S data. Using the different molecular tracers gives complementary information about the gas density structure, due to the different critical densities, and different isotopomers allows correction for optical depth effects.

The SIM (Planet Quest) mission is a space-based long-baseline stellar interferometer designed for ultra-precise astrometry. This paper describes how SIM can be used for double star research. There are several regimes of operation. For binary stars separated by more than 1″.5, SIM treats these as distinct objects. Double stars less than ∼10 milliarcsec in separation are seen as a single object and SIM measures the photocenter of the composite object. Between 10 mas and 1″.15, SIM is able to see the double star as two distinct objects, but because photons from both stars are detected there is the possibility of increased noise and measurement bias. This paper describes how double stars are observed with SIM and what information can be derived.

The Spacewatch Project at the University of Arizona uses a 0.9-meter and a 1.8-meter telescope to search for new Near-Earth Objects (NEOs) and make astrometric followup measurements of known ones. Among the presently operational asteroid astrometry programs, Spacewatch is uniquely suited to support discoveries by the planned deep all-sky surveys. The Spacewatch 1.8-meter telescope is the largest in the world that is used exclusively for observations of asteroids and comets. Since 2003 January 1, Spacewatch has made ~2400 separate-night detections (discoveries plus followup) of NEOs with absolute magnitude H≤ 22, including 117 fresh discoveries of NEOs with H≤22 and ~900 separate-night detections of Potentially Hazardous Asteroids (PHAs). Objects have been recovered at V=23 and at elongations less than 60 degrees from the Sun. Spacewatch followup observations have contributed to the removal of 137 objects from JPL's impact risk website. Examples of notable recoveries by Spacewatch include the extension of orbital arcs from one month to multi-opposition orbits, and a successful targeted search for a large PHA (1990 SM) with 80 degrees of uncertainty. Spacewatch has been making as many observations of PHAs with H≤22 and V>21 as all other followup stations combined. Followup of NEOs while they are not near Earth provides better leverage on orbital elements and will be well suited to follow up some of the discoveries by the larger-scale, deeper sky surveys: both ground- and space-based. Spacewatch is collaborating with the Panoramic Survey Telescope and Rapid Response System (PS) of the University of Hawaii's Institute for Astronomy. Each lunation, Spacewatch sends its listings of point sources detected in survey images for PS's moving object detection team to test their software. Spacewatch is also prepared to follow up objects of special interest, fast motion, or less than three nights of observations by PS itself. Spacewatch's current equipment is only a few years old, but there is still room to improve limiting magnitude & time efficiency.

Many clues about the galaxy assembly process lurk in the faint outer regions of galaxies. Although quantitative study of these parts has been severely limited in the past, breakthroughs are now being made thanks to the combination of wide-area star counts, deep HST imagery and 8-m class spectroscopy. I highlight here some recent progress made on deciphering the fossil record encoded in the outskirts of our nearest large neighbours, M31 and M33.

We study fossil galaxy groups, their hot gas and the galaxy properties. Fossils are more X-ray luminous than non-fossil groups, however, they fall comfortably on the conventional L-T relation of galaxy groups and clusters indicating that their X-ray luminosity and temperature are both boosted, arguably, as a result of their early formation. The central dominant galaxy in fossils have optical luminosity comparable to the brightest cluster galaxies (BCGs), however, the isophotal shapes of the central galaxy in fossils are non-boxy in contrast to the isophotes of majority of the BCGs.

The Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) at the University of Hawaii's Institute for Astronomy is a funded project to repeatedly survey the entire visible sky to faint limiting magnitudes (mR ~ 24). It will be composed of four 1.8m diameter apertures each outfitted with fast readout orthogonal transfer Giga-pixel CCD cameras. A single aperture prototype telescopes has achieved first-light in the second half of 2006 with the full system becoming available a few years later. Roughly 60% of the surveying will be suitable for discovery of new solar system objects and it will cover the ecliptic, opposition and low solar-elongation regions. In a single lunation Pan-STARRS will detect about five times more solar system objects than the entire currently known sample. Within its first year Pan-STARRS will have detected 20,000 Kuiper Belt Objects and by the end of its ten year operational lifetime we expect to have found 107 Main Belt objects and achieve ~90% observational completeness for all NEOs larger than ~300m diameter. With these data in hand Pan-STARRS will revolutionize our knowledge of the contents and dynamical structure of the solar system.

We have found photometric indications that Interacting Eclipsing Binaries of early to mid F spectral type (and possibly A) have strong magnetic activity which would arise from convective atmospheres. Light curve solutions and periodicity studies revealing spots, magnetic breaking and magnetic cycles are presented in XZ CMi, V965 Cyg and V963 Cyg.

A recent analysis of HST optical images of 34 nearby early-type active galaxies and of a matched sample of 34 inactive galaxies – both drawn from the Palomar survey – shows a clear excess of nuclear dusty structures (filaments, spirals and disks) in the active galaxies. This result supports the association of the dusty structures with the material which feeds the supermassive black hole (hereafter SMBH). Among the inactive galaxies there is instead an excess of nuclear stellar disks. As the active and inactive galaxies can be considered two phases of the “same” galaxy, the above findings and dust morphologies suggest an evolutionary scenario in which external material (gas and dust) is captured to the nuclear region where it settles and ends up feeding the active nucleus and replenishing the stellar disk – which is hidden by the dust in the active galaxies – with new stars. This evolutionary scenario is supported by recent gas kinematics of the inner few hundred parsecs of NGC 1097, which shows streaming motions (with velocities ∼50 km s−1) towards the nucleus along spiral arms. The implied large scale mass accretion rate is much larger than the one derived in previous studies for the nuclear accretion disk, but is just enough to accumulate one million solar masses over a few million years in the nuclear region, thus consistent with the recent finding of a young circumnuclear starburst of one million solar masses within 9 parsecs from the nucleus in this galaxy.

We summarize findings from imaging surveys of 143 early-type galaxies in the Virgo and Fornax Clusters. Using deep HST images in the F475W (g) and F850LP (z) band-passes obtained with the Advanced Camera for Surveys (ACS), we have examined the central structure of the program galaxies, finding clear evidence for a compact stellar nucleus in ∼ 75% of the sample. The formation of early-type galaxies of low- and intermediate-mass is often – but not always – accompanied by the formation of a compact stellar nucleus.

We list below a few problems whose resolution might bring new lights on the impacts of the first stellar generations on the early phases of the evolution of the galaxies.

The Arecibo Galaxy Environment Survey (AGES, Auld et al. 2006) will map ~200 square degrees over the next years using the ALFA feed array at the 305-m Arecibo Telescope. AGES is specifically designed to investigate various galactic environments from local voids to interacting groups and cluster of galaxies. AGES will map 20 square degrees in the Coma-Abell1367 supercluster including the Abell cluster 1367 and its outskirts (up to ~2 virial radii). In Spring 2006 we nearly completed the observations of 5 square degrees in the range 11:34< RA< 11:54, 19:20<Dec<20:20 covering all the cluster core and part of its infalling region reaching a 5 sigma detection limit of M(HI)~4×108M⊙ (assuming a velocity width ~200 km~s−1) at the distance of Abell1367 (~92 Mpc). An HI selected sample has been extracted from the datacube obtaining a catalogue of fluxes, recessional velocities, positions and velocity widths. We present a preliminary analysis of the properties of the HI sources and report the discovery of HI diffuse features within interacting groups at the periphery of Abell1367.

The Minimum Orbit Intersection Distance (MOID) between two confocal Keplerian orbits is a useful tool to know if two celestial bodies can collide or undergo a very close approach. We describe some results and open problems on the number of local minimum points of the distance between two points on the two orbits and the position of such points with respect to the mutual nodes. The errors affecting the observations of an asteroid result in uncertainty in its orbit determination and, consequently, uncertainty in the MOID. The latter is always positive and is not regular where it vanishes; this prevents us from considering it as a Gaussian random variable, and from computing its covariance by standard tools. In a recent work we have introduced a regularization of the maps giving the local minimum values of the distance between two orbits. It uses a signed value of the distance, with the sign given to the MOID according to a simple orientation property. The uncertainty of the regularized MOID has been computed for a large database of orbits. In this way we have searched for Virtual PHAs, i.e. asteroids which can belong to the category of PHAs (Potentially Hazardous Asteroids) if the errors in the orbit determination are taken into account. Among the Virtual PHAs we have found objects that are not even NEA, according to their nominal orbit.

We present our recent work on the conditions under which star formation occurs in a metal-poor environment, the Large Magellanic Cloud ([Fe/H] ~ −0.4). Water masers are used as beacons of the current star formation in H II regions. Comparing their location with the dust morphology imaged with the Spitzer Space Telescope, and additional Hα imaging and groundbased near-infrared observations, we conclude that the LMC environment seems favourable to sequential star formation triggered by massive star feedback (Oliveira et al. 2006). Good examples of this are 30 Doradus and N 113. There are also H II regions, such as N 105A, where feedback may not be responsible for the current star formation although the nature of one young stellar object (YSO) suggests that feedback may soon start making an impact. The chemistry in one YSO hints at a stronger influence from irradiation effects in a metal-poor environment where shielding by dust is suppressed (van Loon 2005).

The solar magnetic field and its associated atmospheric activity exhibits periodic variations on a number of time scales. The 11-year sunspot cycle and its underlying 22-year magnetic cycle are, besides the 5-minute oscillation, the most widely known. Amplitudes and periods range from a few parts per million (ppm) and 2–3 minutes for p-modes in sunspots, a few 10 ppm and 10 minutes for the granulation turn around, a few 100 ppm and weeks for the lifetime of plages and faculae, 1000 ppm and 27 days for the rotational signal from spots, to the long-term cycles of 90 yr (Gleissberg cycle), 200 - 300 yr (Wolf, Spörer, Maunder minima), 2,400 yr from 14C tree-ring data, and possibly in excess of 100,000 yr.

A sample of potential massive starforming regions identified at 170 m by ISO was observed in the submillimeter and millimeter regime. These observations allow us to infer physical properties of the molecular cloud cores. Two sources are presented in detail: ISOSS J23053+5953 and J183640221 show viable candidates for massive protocluster cores. Our analysis shows very low temperatures and low levels of turbulence of the major mass fraction in the molecular cloud cores besides active star formation at an early evolutionary stage. These conditions seem similar to the low mass case and may precede phases of luminous infrared emission observed towards young massive protostars.

We have performed numerical simulations which were designed to further our understanding of the turbulent interstellar medium (ISM). Our simulations include a multi-phase thermodynamic model of the ISM, magnetic fields, and sheared rotation, allowing us to study the effects of the magnetorotational instability (MRI) in an environment containing high density cold clouds embedded in a warm, low density, ambient medium. These models have shown that the MRI is indeed a significant source of turbulence, particularly at low mean densities typical of the outer regions of the Milky Way, where star formation rates are low, but high levels of turbulence persist. Here, we summarize past findings, as well as our most recent models which include vertical stratification, allowing us to self-consistently model the vertical distribution of material in the disk.

Thermal convection occurs in most objects that populate our Universe, whenever radiation is insufficient to transport the heat because the medium is too opaque. In astrophysical objects convection involves a wide range of spatial and temporal scales - experts call this turbulence - which makes it rather difficult to model. For this reason convection remains one of the major uncertainties when modeling stars and planets, and this is partly true also for accretion disks. However, substantial progress has been achieved during the past years, both in the numerical simulation of convective regions and in the observation of convective flows by various new techniques.