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WWW, its interfaces and tools, can represent a big opportunity to solve some historical problems of the astronomers. After a description of the state of the Italian Astronomy and Astrophysics environment, with special emphasis to the network usage and to the development of two challenging new technology telescopes, some of the more important (for us) topics are discussed. Several of the major points described in this paper have been outlined and exposed by several authors during a recent Workshop devoted to the first experiments with WWW in the Italian Astronomical Observatories. The application to a very promising field, the astronomical archives, and its fall-out on the organization of the work in observational astronomy is finally discussed.

We study the effect of neutrino flux regeneration by neutral current on the Standard Model prediction for the recently proposed observable angular α_SM(E). This observable has a weak dependence with the initial flux through the regeneration term in the transport equation. We want to know the impact of the initial flux uncertainties on the mentioned observable.

Everyone knows Galileo Galilei as an astronomer, physicist and writer of books that changed our perception of the world. Few people know that Galileo also wrote poetry in elegant XVI century Italian. In 1590, aged 26, Galileo was a lecturer of mathematics at the University of Pisa, the poorest paid of the faculty. He dutifully taught Euclid, but quickly ran into trouble: he despised and openly challenged Pisa's strict academic traditions. Especially the rule by which all professors had to wear their gown at all times, under penalty of a stiff fine. To chastise and mock such rule, he wrote his longest poem, the 301-line Capitolo "Against the Donning of the Gown".

Since its completion in 2008, ANTARES is the largest neutrino telescope operating in the Northern hemisphere. High-energy muon-neutrinos originating from galactic and extra-galactic sources cross the earth and produce up-going muons by charged current interaction in the medium just below the bottom of the sea or in the water around it. These muons travel through the water with the emission of Cerenkov light detected by a three-dimensional array of photomultipliers tubes (PMT). The performances and the first results of the telescope will be discussed.

In this paper, we present the historical background of the Thirty-Meter Telescope at Mount Mauna Kea and a few facts regarding scientific advancement. However, we will not focus on any politically motivated matters and ethical issues, rather our sincere concern is to highlight the overall history, philosophy, science and technology which have prevailed for any civilized advancement of the society.

The Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLASTPol) was a suborbital experiment designed to map magnetic fields in order to study their role in star formation processes. BLASTPol made detailed polarization maps of a number of molecular clouds during its successful flights from Antarctica in 2010 and 2012. We present the next-generation BLASTPol instrument (BLAST-TNG) that will build off the success of the previous experiment and continue its role as a unique instrument and a test bed for new technologies. With a 16-fold increase in mapping speed, BLAST-TNG will make larger and deeper maps. Major improvements include a 2.5-m carbon fiber mirror that is 40% wider than the BLASTPol mirror and ~3000 polarization sensitive detectors. BLAST-TNG will observe in three bands at 250, 350, and 500 μm. The telescope will serve as a pathfinder project for microwave kinetic inductance detector (MKID) technology, as applied to feedhorn-coupled submillimeter detector arrays. The liquid helium cooled cryostat will have a 28-day hold time and will utilize a closed-cycle ³He refrigerator to cool the detector arrays to 270 mK. This will enable a detailed mapping of more targets with higher polarization resolution than any other submillimeter experiment to date. BLAST-TNG will also be the first balloon-borne telescope to offer shared risk observing time to the community. This paper outlines the motivation for the project and the instrumental design.

For the first time to our knowledge, we experimentally demonstrate a clock signal transmission using a counter-propagating Raman pump as a transmitter and concurrently utilize the same pump to amplify a data signal. A 1548nm vertical cavity surface emitting laser (VCSEL) was modulated with a pseudorandom bit sequence (2${}^7-1$) and coupled into an optical fiber. A 1448nm Raman pump in the backward scheme was also modulated with a 10kHz clock and used to boost the VCSEL data signal so as to improve the reach of the transmission. Clock distribution in a telescope network such as the Square Kilometre Array (SKA) is essential for the proper operation of the digitizers as well as dish synchronization. In the SKA phase 1, long transmissions involving baselines extending up to 100km may need amplification. We propose the use of counter-Raman configuration to amplify the signal carrying received astronomical data while transmitting a clock to the receptors. This is a cost-effective bi-directional transmission suited for telescope network applications.

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a heavily modified Boeing 747SP aircraft, accommodating a 2.7m infrared telescope. This airborne observation platform operates at flight altitudes of up to 13.7km (45,000ft) and therefore allows a nearly unobstructed view of the visible and infrared universe at wavelengths between 0.4μm and 1600μm. The Focal Plane Imager (FPI+) is SOFIA’s main tracking camera. It uses a commercial, off-the-shelf camera with a thermoelectrically cooled EMCCD. The back-illuminated sensor has a peak quantum efficiency greater than 95% at 550nm and the dark current is as low as 0.001 e-/pix/sec. Since 2015, the FPI$+$ has been available to the community as a Facility Science Instrument (FSI), and can be used as a high speed photometer for events in the visual wavelength range.

This paper presents a detailed overview of the design and optical configuration of the FPI+. Different settings and specifications of the camera are explained and the focal plane sensor is described. The camera’s performance in regards to sensitivity and frame rate is shown. The operation of the instrument is described as well as the support for guest observers throughout the process from proposing to data analysis. To date, SOFIA has conducted multiple FPI+ observations of stellar occultations, e.g. occultations by Pluto in 2011 and 2015, the occultation by 2014MU69 in July 2017 and the occultation by Triton in October 2017. Additionally, multiple observations of exo-planet transits have been observed with the FPI+. Throughout these observations, the FPI+ has proven to be an excellent photometer for astronomical events that have challenging requirements for sensitivity and temporal resolution.

The SOFIA telescope is a 2.5m class Cassegrain telescope with Nasmyth focus. It is the largest telescope ever integrated into an aircraft. The telescope is exposed to the stratospheric environment during the observations and the fact that the telescope’s foundation, which is a Boeing 747 SP, is vibrating and moving in all degrees of freedom (DoF) requires a highly specialized and sophisticated design. Based on the telescope of its predecessor, the Kuiper Airborne Observatory (KAO), the SOFIA telescope design had to evolve to accommodate a telescope 2.5 times the size of KAO. In several hundred successful observation flights, the telescope proved that it performs not only as specified, but is also extremely reliable. Nevertheless, the telescope’s software and hardware are continuously upgraded to optimize its performance without interfering with the observation schedules to reach even more ambitious image size and pointing jitter goals to enable additional science cases. In addition, manufacturing of the line-replaceable units is in process to ensure that the SOFIA telescope can perform without any major interruptions for the envisioned 20 year lifetime. Some of the main features of the SOFIA telescope are its suspension assembly (SUA), which decouples the telescope from SOFIA’s fuselage with air springs and a spherical oil bearing, the extremely stiff Nasmyth tube (NT), which connects cavity and cabin mounted components of the dumbbell design, and the Secondary Mirror Assembly (SMA), which is used for chopping and fast pointing corrections. This paper aims to give an overview of these and all other major telescope subsystems in operation today. In addition, some of the upgrades, either implemented recently or slated for implementation shortly, are introduced.

Focal ratio degradation (FRD), the decrease of light’s focal ratio between the input into an optical fiber and the output, is important to characterize for astronomical spectrographs due to its effects on throughput and the point spread function. However, while FRD is a function of many fiber properties such as stresses, microbending, and surface imperfections, angular misalignments between the incoming light and the face of the fiber also affect the light profile and complicate this measurement. A compact experimental setup and a model separating FRD from angular misalignment was applied to a fiber subjected to varying stresses or angular misalignments to determine the magnitude of these effects. The FRD was then determined for a fiber in a fiber positioner that will be used in the Subaru Prime Focus Spectrograph (PFS). The analysis we carried out for the PFS positioner suggests that effects of angular misalignment dominate and no significant FRD increase due to stress should occur.

This paper studies about the 130-cm Devasthal Fast Optical Telescope (DFOT) at Devasthal, India that has been in operation for more than 10 years and is the main workhorse for the photometric observations for a wide range of scientific programs carried out at ARIES, Nainital. Having a $2\mathrm{\text{k}}\times 2\mathrm{\text{k}}$ pixel imager mounted on the prime focus of the telescope, DFOT provides a field of view of about $18\times 18$ arcmin² in the sky. Another frame transfer CCD imager of $512\times 512$ pixel size enables monitoring transient sources with millisecond temporal resolution. DFOT is equipped with a filter assembly having eight filters, an auto-guider, an All Sky Camera, and GPS-enabled weather monitoring system to support the observations in the most optimum way. The telescope is capable of producing sub-milimag photometric stability which has allowed us to detect many small-scale photometric variations.