The second flight of the SUNRISE balloon-borne solar observatory: overview of instrument updates, the flight, the data and first results

The SUNRISE balloon-borne solar observatory, consisting of a 1~m aperture telescope that provided a stabilized image to a UV filter imager and an imaging vector polarimeter, carried out its second science flight in June 2013. It provided observations of parts of active regions at high spatial resolution, including the first high-resolution images in the Mg~{\sc ii}~k line. The obtained data are of very high quality, with the best UV images reaching the diffraction limit of the telescope at 3000~\AA\ after Multi-Frame Blind Deconvolution reconstruction accounting for phase-diversity information. Here a brief update is given of the instruments and the data reduction techniques, which includes an inversion of the polarimetric data. Mainly those aspects that evolved compared with the first flight are described. A tabular overview of the observations is given. In addition, an example time series of a part of the emerging active region NOAA AR~11768 observed relatively close to disk centre is described and discussed in some detail. The observations cover the pores in the trailing polarity of the active region, as well as the polarity inversion line where flux emergence was ongoing and a small flare-like brightening occurred in the course of the time series. The pores are found to contain magnetic field strengths ranging up to 2500~G and, while large pores are clearly darker and cooler than the quiet Sun in all layers of the photosphere, the temperature and brightness of small pores approach or even exceed those of the quiet Sun in the upper photosphere.Comment: Accepted for publication in The Astrophysical Journa

Biodegradable DFADs: Current status and prospects

Until recently, dFAD structure, materials and designs have remained quite rudimentary and virtually the same since their discovery, characterized by the increase of the dimensions and prevailing heavy use of plastic components. Biodegradable materials are called to be an important part of the solution, as they can faster degrade in the environment, free of toxins and heavy metals, reducing their lifespan, and preventing them from accumulating in sensitive areas once they are abandoned, lost or discarded. During last decades, regulatory measures at tRFMOs have advanced in the gradual implementation of biodegradable materials in dFAD constructions together with other measures limiting the number of active dFADs and the use of netting materials. However, more clarity is needed starting with a standardised definition of biodegradable dFADs among tRFMOs, to provide operational guidance. Research with those natural and synthetic materials is required, along with updated data collection for monitoring standards, as well as alternative and complementary actions need to be explored to contribute to minimising dFAD adverse effects on environment. Acknowledging the current difficulties for the implementation of fully biodegradable dFADs a stepwise process towards the implementation of fully biodegradable dFADs should be considered.Postprin

Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) for Sunrise III: Thermal-Vacuum Test of the SCIP Optical Unit

Ground-based and airborne instrumentation for astronomy IX (2022), Montreal, jul 17-22, 2022.--Proceedings of SPIE - The International Society for Optical Engineering vol. 12184 Article number 121842BThe Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) is an instrument for the third flight of the Sunrise balloon-borne solar observatory planned for 2022. To verify the high spatial and spectral resolutions required in the balloon flight, the SCIP optical unit was subjected to a thermal-vacuum test in which the SCIP optical unit was installed in a vacuum chamber and was exposed to the thermal vacuum environment expected in the balloon flight. We verified the heater control performance and the temperature distribution in the SCIP optical unit in hot and cold conditions created by the shrouds in the vacuum chamber. We confirmed the optical performance, such as spatial and spectral resolution, and an air-to-vacuum difference of the optics by injecting the laser and white lights through a vacuum window.The Sunrise III balloon project is funded in Japan by the ISAS/JAXA Small Mission-of-Opportunity program for novel solar observations and JSPS KAKENHI Grant Number 18H05234 (PI: Y. Katsukawa). We would also thank the significant technical support given by the Advanced Technology Center (ATC), NAOJ. The Spanish contribution to Sunrise III has been supported by the Spanish Ministry of Science and Innovation through projects and ESP-2016-77548-C5-1-R and RTI2018-096886-B-C51 by "Centro de Excelencia Severo Ochoa" Program under grant SEV-2017-0709. D.O.S. also acknowledges financial support through the Ramon y Cajal fellowship. The German contribution to Sunrise III is funded by the Max Planck Foundation, the Strategic Innovations Fund of the President of the Max Planck Society (MPG), the Deutsches Zentrum fur Luft und Raumfahrt (DLR), and private donations by supporting members of the Max Planck Society, which is gratefully acknowledged.Peer reviewe

Anisotropy studies around the galactic centre at EeV energies with the Auger Observatory

Data from the Pierre Auger Observatory are analyzed to search for anisotropies near the direction of the Galactic Centre at EeV energies. The exposure of the surface array in this part of the sky is already significantly larger than that of the fore-runner experiments. Our results do not support previous findings of localized excesses in the AGASA and SUGAR data. We set an upper bound on a point-like flux of cosmic rays arriving from the Galactic Centre which excludes several scenarios predicting sources of EeV neutrons from Sagittarius $A$. Also the events detected simultaneously by the surface and fluorescence detectors (the `hybrid' data set), which have better pointing accuracy but are less numerous than those of the surface array alone, do not show any significant localized excess from this direction.Comment: Matches published versio

Intensity contrast of solar network and faculae close to the solar limb, observed from two vantage points

The brightness of faculae and network depends on the angle at which they are observed and the magnetic flux density. Close to the limb, assessment of this relationship has until now been hindered by the increasingly lower signal in magnetograms. This preliminary study aims at highlighting the potential of using simultaneous observations from different vantage points to better determine the properties of faculae close to the limb. We use data from the Solar Orbiter/Polarimetric and Helioseismic Imager (SO/PHI), and the Solar Dynamics Observatory/Helioseismic and Magnetic Imager (SDO/HMI), recorded at $\sim60^\circ$ angular separation of their lines of sight at the Sun. We use continuum intensity observed close to the limb by SO/PHI and complement it with the co-observed $B_{\rm LOS}$ from SDO/HMI, originating closer to disc centre (as seen by SDO/HMI), thus avoiding the degradation of the magnetic field signal near the limb. We derived the dependence of facular brightness in the continuum on disc position and magnetic flux density from the combined observations of SO/PHI and SDO/HMI. Compared with a single point of view, we were able to obtain contrast values reaching closer to the limb and to lower field strengths. We find the general dependence of the limb distance at which the contrast is maximum on the flux density to be at large in line with single viewpoint observations, in that the higher the flux density is, the closer the turning point lies to the limb. There is a tendency, however, for the maximum to be reached closer to the limb when determined from two vantage points. We note that due to the preliminary nature of this study, these results must be taken with caution. Our analysis shows that studies involving two viewpoints can significantly improve the detection of faculae near the solar limb and the determination of their brightness contrast relative to the quiet Sun

The ratio of horizontal to vertical displacement in solar oscillations estimated from combined SO/PHI and SDO/HMI observations

In order to make accurate inferences about the solar interior using helioseismology, it is essential to understand all the relevant physical effects on the observations. One effect to understand is the (complex-valued) ratio of the horizontal to vertical displacement of the p- and f-modes at the height at which they are observed. Unfortunately, it is impossible to measure this ratio directly from a single vantage point, and it has been difficult to disentangle observationally from other effects. In this paper we attempt to measure the ratio directly using 7.5 hours of simultaneous observations from the Polarimetric and Helioseismic Imager on board Solar Orbiter and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. While image geometry problems make it difficult to determine the exact ratio, it appears to agree well with that expected from adiabatic oscillations in a standard solar model. On the other hand it does not agree with a commonly used approximation, indicating that this approximation should not be used in helioseismic analyses. In addition, the ratio appears to be real-valued.Comment: Accepted for publication in Astronomy & Astrophysics. 8 pages, 8 figure

Management and Outcome of Cardiac and Endovascular Cystic Echinococcosis

Cardiac and vascular involvement are infrequent in classical cystic echinococcosis (CE), but when they occur they tend to present earlier and are associated with complications that may be life threatening. Cardiovascular CE usually requires complex surgery, so in low-income countries the outcome is frequently fatal. This case series describes the characteristics of cardiovascular CE in patients diagnosed and treated at a Tropical Medicine & Clinical Parasitology Center in Spain. A retrospective case series of 11 patients with cardiac and/or endovascular CE, followed-up over a period of 15 years (1995–2009) is reported. The main clinical manifestations included thoracic pain or dyspnea, although 2 patients were asymptomatic. The clinical picture and complications vary according to cyst location. Isolated cardiac CE may be cured after surgery, while endovascular extracardiac involvement is associated with severe chronic complications. CE should be included in the differential diagnosis of cardiovascular disease in patients from endemic areas. CE is a neglected disease and further studies are necessary in order to make more definite management recommendations for this rare and severe form of the disease. The authors propose a general approach based on cyst location: exclusively cardiac, endovascular or both

The Mars Environmental Dynamics Analyzer, MEDA. A Suite of Environmental Sensors for the Mars 2020 Mission

86 pags., 49 figs., 24 tabs.NASA’s Mars 2020 (M2020) rover mission includes a suite of sensors to monitor current environmental conditions near the surface of Mars and to constrain bulk aerosol properties from changes in atmospheric radiation at the surface. The Mars Environmental Dynamics Analyzer (MEDA) consists of a set of meteorological sensors including wind sensor, a barometer, a relative humidity sensor, a set of 5 thermocouples to measure atmospheric temperature at ∼1.5 m and ∼0.5 m above the surface, a set of thermopiles to characterize the thermal IR brightness temperatures of the surface and the lower atmosphere. MEDA adds a radiation and dust sensor to monitor the optical atmospheric properties that can be used to infer bulk aerosol physical properties such as particle size distribution, non-sphericity, and concentration. The MEDA package and its scientific purpose are described in this document as well as how it responded to the calibration tests and how it helps prepare for the human exploration of Mars. A comparison is also presented to previous environmental monitoring payloads landed on Mars on the Viking, Pathfinder, Phoenix, MSL, and InSight spacecraft.This work has been funded by the Spanish Ministry of Economy and Competitiveness, through the projects No. ESP2014-54256-C4-1-R (also -2-R, -3-R and -4-R) and AYA2015-65041-P; Ministry of Science, Innovation and Universities, projects No. ESP2016-79612-C3-1-R (also -2-R and -3-R), ESP2016-80320-C2-1-R, RTI2018-098728-B-C31 (also -C32 and -C33) and RTI2018-099825-B-C31; Instituto Nacional de Técnica Aeroespacial; Ministry of Science and Innovation’s Centre for the Development of Industrial Technology; Grupos Gobierno Vasco IT1366-19; and European Research Council Consolidator Grant no 818602. The US co-authors performed their work under sponsorship from NASA’s Mars 2020 project, from the Game Changing Development program within the Space Technology Mission Directorate and from the Human Exploration and Operations Directorate

Coronal voids and their magnetic nature

Context: Extreme ultraviolet (EUV) observations of the quiet solar atmosphere reveal extended regions of weak emission compared to the ambient quiescent corona. The magnetic nature of these coronal features is not well understood. // Aims: We study the magnetic properties of the weakly emitting extended regions, which we name coronal voids. In particular, we aim to understand whether these voids result from a reduced heat input into the corona or if they are associated with mainly unipolar and possibly open magnetic fields, similar to coronal holes. // Methods: We defined the coronal voids via an intensity threshold of 75% of the mean quiet-Sun (QS) EUV intensity observed by the high-resolution EUV channel (HRIEUV) of the Extreme Ultraviolet Imager on Solar Orbiter. The line-of-sight magnetograms of the same solar region recorded by the High Resolution Telescope of the Polarimetric and Helioseismic Imager allowed us to compare the photospheric magnetic field beneath the coronal voids with that in other parts of the QS. // Results: The coronal voids studied here range in size from a few granules to a few supergranules and on average exhibit a reduced intensity of 67% of the mean value of the entire field of view. The magnetic flux density in the photosphere below the voids is 76% (or more) lower than in the surrounding QS. Specifically, the coronal voids show much weaker or no network structures. The detected flux imbalances fall in the range of imbalances found in QS areas of the same size. // Conclusions: We conclude that coronal voids form because of locally reduced heating of the corona due to reduced magnetic flux density in the photosphere. This makes them a distinct class of (dark) structure, different from coronal holes