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We still do not understand how planets form or why extrasolar planetary systems are so different from our own Solar System. However, the past few years have dramatically changed our view of the disks of gas and dust around young stars. Observations with the Atacama Large Millimeter/submillimeter Array and extreme adaptive-optics systems have revealed that most—if not all—disks contain substructure, including rings and gaps1–3, spirals4–6, azimuthal dust concentrations7 and shadows cast by misaligned inner disks5,8. These features have been interpreted as signatures of newborn protoplanets, but the exact origin is unknown. Here we report the kinematic detection of a few-Jupiter-mass planet located in a gas and dust gap at 130 au in the disk surrounding the young star HD 97048. An embedded planet can explain both the disturbed Keplerian flow of the gas, detected in CO lines, and the gap detected in the dust disk at the same radius. While gaps appear to be a common feature in protoplanetary disks2,3, we present a direct correspondence between a planet and a dust gap, indicating that at least some gaps are the result of planet–disk interactions.Pinte et al. report the kinematic detection of a few-Jupiter-mass planet orbiting at 130 au from the young star HD 97048. The radial position of the planet coincides with a gap in both the gas and dust components of the protoplanetary disk, showing that at least some gaps can be linked to the presence of planets.

The AGATA and GRETA spectrometers are large arrays of highly segmented HPGe detectors that use the technique of gamma ray tracking to reconstruct the scattering path of gamma rays interacting within the active material. A basic requirement is a precise reconstruction of the individual interaction locations within the detectors. This is possible through the use of pulse shape analysis which has to be conducted in real time due to the high data rates generated by the spectrometer. The methodologies that have been evaluated to perform this for AGATA are discussed along with the approaches used to calculate the pulse shape databases required by these algorithms. Finally, the performance and limitations of the existing approaches are reviewed.

The AGATA collaboration has a long-standing leadership in the development of front-end electronics for high resolution γ -ray spectroscopy using large volume high purity germanium detectors. For two decades, the AGATA collaboration has been developing state-of-the-art digital electronics processing with high resolution sampling ADC, high-speed signal transfer and fast readout to a high throughput computing (HTC) farm for on-line pulse shape analysis. The collaboration is presently addressing the next challenge of equipping a 4 π array with more than 6000 channels in high resolution mode, generating approximately 10 MHz of total trigger requests, coupled to a large variety of complementary instruments. A next generation of front-end electronics, presently under design, is based on industrial products (System on Module FPGA’s), has higher integration and lower power consumption. In this contribution, the conceptual design of the new electronics is presented. The results of the very first tests of the pre-production electronics are presented as well as future perspectives.

The explosion that results in a cosmic γ-ray burst (GRB) is thought to produce emission from two physical processes: the central engine gives rise to the high-energy emission of the burst through internal shocking 1 , and the subsequent interaction of the flow with the external environment produces long-wavelength afterglows 2 , 3 , 4 . Although observations of afterglows 5 continue to refine our understanding of GRB progenitors and relativistic shocks, γ-ray observations alone have not yielded a clear picture of the origin of the prompt emission 6 nor details of the central engine. Only one concurrent visible-light transient has been found 7 and it was associated with emission from an external shock. Here we report the discovery of infrared emission contemporaneous with a GRB, beginning 7.2 minutes after the onset of GRB 041219a (ref. 8 ). We acquired 21 images during the active phase of the burst, yielding early multi-colour observations. Our analysis of the initial infrared pulse suggests an origin consistent with internal shocks.

By virtue of their young age and intermediate mass, Herbig AeBe stars represent a cornerstone for our understanding of the mass-dependency of both the stellar and planetary formation processes. In this contribution, I review the current state-of-the-art multiplicity surveys of Herbig AeBe stars to assess both the overall frequency of companions and the distribution of key orbital parameters (separation, mass ratio and eccentricity). In a second part, I focus on the interplay between the multiplicity of Herbig AeBe stars and the presence and properties of their protoplanetary disks. Overall, it appears that both star and planet formation in the context of intermediate-mass stars proceed following similar mechanisms to lower-mass stars.

We present a review of the interplay between the evolution of circumstellar disks and the formation of planets, both from the perspective of theoretical models and dedicated observations. Based on this, we identify and discuss fundamental questions concerning the formation and evolution of circumstellar disks and planets which can be addressed in the near future with optical and infrared long-baseline interferometers. Furthermore, the importance of complementary observations with long-baseline (sub)millimeter interferometers and high-sensitivity infrared observations is outlined.

Directly detecting thermal emission from young extrasolar planets allows measurement of their atmospheric compositions and luminosities, which are influenced by their formation mechanisms. Using the Gemini Planet Imager, we discovered a planet orbiting the ∼20-million-year-old star 51 Eridani at a projected separation of 13 astronomical units. Near-infrared observations show a spectrum with strong methane and water-vapor absorption. Modeling of the spectra and photometry yields a luminosity (normalized by the luminosity of the Sun) of 1.6 to 4.0 × 10–6 and an effective temperature of 600 to 750 kelvin. For this age and luminosity, \"hot-start\" formation models indicate a mass twice that of Jupiter. This planet also has a sufficiently low luminosity to be consistent with the \"cold-start\" core-accretion process that may have formed Jupiter.

Edge-on, optically thick circumstellar disks have been previously imaged at subarcsecond resolution around about a dozen nearby young stellar objects. In these systems the central star is occulted from direct view, bright star image artifacts are absent, and the disk reflected light is clearly seen. Comparison of Hubble Space Telescope (HST) edge-on disk images with scattered light models has allowed key disk structural parameters and dust grain properties to be determined. Edge-on disks have been systematically undercounted to date: while 10% of young stars should statistically be occulted by their disk, the observed frequency is much less. Thus there is a significant potential for discovering and imaging new examples. Spitzer Space Telescope legacy science programs have provided the first good spectral energy distribution (SED) measurements for the previously known edge-on disks. These can be used as templates to identify new candidates in far-infrared survey datasets. We report on the results of our HST program to image twenty-one edge-on disk candidates mostly selected from their SEDs. Eleven are well-resolved with radii ranging from 30-400 AU, nine for the first time and six showing highly collimated jets. Outstanding individual sources include a large and symmetric new template object, a highly flattened disk not accreting onto its central star, and an asymmetric disk with a misaligned jet which likely traces tidal perturbations in a binary system. Follow-up work to obtain ancillary data and perform scattered light modeling of the most symmetric disks is now being pursued. The results of this program will guide a new round of searches for these rare but important snapshots of protoplanetary disk evolution.

We present new high-resolution observations and modeling of SSTtau J042021+ 281349, a 400 AU-radius edge-on protoplanetary disk. We have gathered visible and near-infrared scattered light images of the system with the Hubble Space Telescope and Keck adaptive optics system, as well as a 1.3 mm continuum map with CARMA. Compared to the well-known HH 30 disk, this new system is remarkable because of its spectacular bipolar jet and the high degree of lateral symmetry of the disk. Indeed, we argue that this system is a “cleaner” prototype for edge-on disks. In addition, the apparent achromaticity of dust properties (most notably the almost grey opacity law) from the visible to the near-infrared in this disk suggests that it is in an advanced stage of dust evolution.