The Sunrise balloon-borne solar observatory consists of a 1 m aperture Gregory telescope, a UV filter imager, an imaging vector polarimeter, an image stabilization system, and further infrastructure. The first science flight of Sunrise yielded high-quality data that revealed the structure, dynamics, and evolution of solar convection, oscillations, and magnetic fields at a resolution of around 100 km in the quiet Sun. After a brief description of instruments and data, the first qualitative results are presented. In contrast to earlier observations, we clearly see granulation at 214 nm. Images in Ca ii H display narrow, short-lived dark intergranular lanes between the bright edges of granules. The very small-scale, mixed-polarity internetwork fields are found to be highly dynamic. A significant increase in detectable magnetic flux is found after phase-diversity-related reconstruction of polarization maps, indicating that the polarities are mixed right down to the spatial resolution limit and probably beyond.

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The first science flight of the balloon-borne Sunrise telescope took place in June 2009 from ESRANGE (near Kiruna/Sweden) to Somerset Island in northern Canada. We describe the scientific aims and mission concept of the project and give an overview and a description of the various hardware components: the 1-m main telescope with its postfocus science instruments (the UV filter imager SuFI and the imaging vector magnetograph IMaX) and support instruments (image stabilizing and light distribution system ISLiD and correlating wavefront sensor CWS), the optomechanical support structure and the instrument mounting concept, the gondola structure and the power, pointing, and telemetry systems, and the general electronics architecture. We also explain the optimization of the structural and thermal design of the complete payload. The preparations for the science flight are described, including AIV and ground calibration of the instruments. The course of events during the science flight is outlined, up to the recovery activities. Finally, the in-flight performance of the instrumentation is discussed.

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How and where are coronal loops rooted in the solar lower atmosphere? The details of the magnetic environment and its evolution at the footpoints of coronal loops are crucial to understanding the processes of mass and energy supply to the solar corona. To address the above question, we use highresolution line-of-sight magnetic field data from the Imaging Magnetograph eXperiment instrument on the Sunrise balloon-borne observatory and coronal observations from the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory of an emerging active region. We find that the coronal loops are often rooted at the locations with minor small-scale but persistent oppositepolarity magnetic elements very close to the larger dominant polarity. These opposite-polarity smallscale elements continually interact with the dominant polarity underlying the coronal loop through flux cancellation. At these locations we detect small inverse Y-shaped jets in chromospheric Ca ii H images obtained from the Sunrise Filter Imager during the flux cancellation. Our results indicate that magnetic flux cancellation and reconnection at the base of coronal loops due to mixed polarity fields might be a crucial feature for the supply of mass and energy into the corona.

The properties of the evolution of solar granulation have been studied using an 80 minute time series of high spatial resolution white-light images obtained with the Swedish Vacuum Solar Telescope at the Observatorio del Roque de los Muchachos, La Palma. An automatic tracking algorithm has been developed to follow the evolution of individual granules, and a sample of 2643 granules has been analyzed. To check the reliability of this automatic procedure, we have manually tracked a sample of 481 solar granules and compared the results of both procedures. An exponential law gives a good Ðt to the distribution of granular lifetimes, T . Our estimated mean lifetime is about 6 minutes, which is at the lower limit of the ample range of values reported in the literature. We note a linear increase in the timeaveraged granular sizes and intensities with the lifetime. T \ 12 minutes marks a sizeable change in the slopes of these linear trends. Regarding the location of granules with respect to the meso-and supergranular Ñow Ðeld, we Ðnd only a small excess of long-lived granules in the upÑows. Fragmentation, merging, and emergence from (or dissolution into) the background are the birth and death mechanisms detected, resulting in nine granular families from the combination of these six possibilities. A comparative study of these families leads to the following conclusions : (1) fragmentation is the most frequent birth mechanism, while merging is the most frequent death mechanism ; (2) spontaneous emergence from the background occurs very rarely, but dissolution into the background is much more frequent ; and (3) di †erent granular mean lifetimes are determined for each of these families ; the granules that are born and die by fragmentation have the longest mean lifetime (9.23 minutes). From a comparison of the evolution of granules belonging to the most populated families, two critical values appear for the initial area in a granular evolution : 0.8 Mm2 and 1.3 Mm2 These values mark limits charac-77). terizing the birth mechanism of a granule, and predict its evolution to some extent. The Ðndings of the present work complement the earlier results presented in this series of papers and reinforce with new inputs, as far as the evolutionary aspects are concerned, the conclusion stated there that granules can be classiÐed into two populations with di †erent underlying physics. The boundary between these two classes could be established at the scale of d g \ 1A .4.

A 90 minute time series of high spatial resolution white-light images of solar granulation, obtained at the Swedish Vacuum Solar Tower (Observatorio del Roque de los Muchachos, La Palma), was analyzed to study how the physical properties of the granules changed with size. The observational material was corrected for global motions and for the instrumental proÐle, and a subsonic Ðlter was applied. A deÐni-tion of granular border was adopted using the inÑection points of the intensity of the images, and the granular cells were deÐned as areas including, in addition to the granules, one-half of their surrounding intergranular lanes. Using time series to investigate the average behavior of solar granulation has three strong advantages : the Ðrst is the possibility of removing the acoustic waves ; second, the possibility of estimating the e †ect of the variability of seeing on our results ; and, third, the opportunity to attain high statistical signiÐcance in the analysis as a result of the large number of extracted granules (61,138).It is shown that the granules of the sample can be classiÐed according to their mean and maximum intensities and their fractal dimension into two regimes, with diameters smaller than and larger than 1A .4, respectively. A broad transition region in which both regimes coexist was found. The resolved internal brightness structure of both the granules and the intergranular lanes shows a linear increase of the number of substructures with the granular and intergranular areas. The diameters of these substructures range between our e †ective resolution limit and with preferential sizes at and (D0A .3) D1A .5, 0A .65 0A .55, respectively. Moreover, it seems that large and small granules are unevenly distributed with respect to the large-scale vertical Ñows. Thus smaller granules are more concentrated along downdrafts whereas larger ones preferentially occupy the updrafts. Finally, a physical scenario compatible with the existence of these two granular populations is discussed.

Aims. We study the recently discovered twisting motion of bright penumbral filaments with the aim of constraining their geometry and the associated magnetic field. Methods. A large sunspot located 40• from disk center was observed at high resolution with the 1-m Swedish Solar Telescope. Inversions of multi-wavelength polarimetric data and speckle reconstructed time series of continuum images were used to determine proper motions, as well as the velocity and magnetic structure in penumbral filaments. Results. The continuum movie reveals apparent lateral motions of bright and dark structures inside bright filaments oriented parallel to the limb, confirming recent Hinode results. In these filaments we measure upflows of ≈ 1.1 km/s on their limbward side and weak downflows on their centerward side. The magnetic field in them is significantly weaker and more horizontal than in the adjacent dark filaments. Conclusions. The data indicate the presence of vigorous convective rolls in filaments with a nearly horizontal magnetic field. These are separated by filaments harbouring stronger, more vertical fields. Because of reduced gas pressure, we see deeper into the latter. When observed near the limb, the disk-centerward side of the horizontal-field filaments appear bright due to the hot wall effect known from faculae. We estimate that the convective rolls transport most of the energy needed to explain the penumbral radiative flux.