The current status of the Watcher robotic telescope is presented in the light of a recenthardware and software upgrade. The latest gamma-ray burst rapid follow-up observations arediscussed, with particular reference to GRB 120711A.

The gamma-ray bursts (GRB) Swift satellite was launched at the end of2004 and is funded until 2014. Its γ-ray, X-ray, and optical-UVinstruments discover and localize about 100 GRBs per year. We report on the success ofthis mission by counting the number of papers with Swift data and theirimpact (i.e., number of citations to those papers) for the publicationyears 2005 to 2011. In the first year, the number of papers was 24, and it steadilyincreased to 287 in the year 2011, reaching Keck. If this trend continues, before the endof the mission Swift may be approaching XMM-Newton and Chandra, with ~400 publications. Science topics of Swift publications have widened over time, andin 2011 almost 3/4 of all publications were about other energetic targets, such as AGN,novae, supernovae, X-ray binaries, pulsars, massive and stellar black holes.

Networked projects e.g. Gamma-Ray Burst follow up optical observationsrequire dense worldwide coverage. We are investigating potentially interesting sites forobservatories in Central Asia where coverage by observatories is still poor. One of themost important parameter of a site is a number of clear night hours. We present firstresults of direct parameter measurements gathered with weather stations and our ownobservations in different sites of Mongolia.

One of the unexplored domains in the study of gamma-ray bursts (GRBs) is the early timephase of the optical light curve. We have proposed Ultra-Fast Flash Observatory (UFFO) toaddress this question through extraordinary opportunities presented by a series of smallspace missions. The UFFO is equipped with a fast-response Slewing Mirror Telescope thatuses a rapidly moving mirror or mirror array to redirect the optical beam rather thanslewing the entire spacecraft or telescope to aim the optical instrument at the GRBposition. The UFFO will probe the early optical rise of GRBs with sub-second response, forthe first time, opening a completely new frontier in GRB and transient studies. Its fastresponse measurements of the optical emission of dozens of GRB each year will provideunique probes of the burst mechanism and test the prospect of GRB as a new standardcandle, potentially opening up the z > 10 universe. We describe the current limit inearly photon measurements, the aspects of early photon physics, our soon-to-be-launchedUFFO-pathfinder mission, and our next planned mission, the UFFO-100.

The UFFO pathfinder mission will attempt to locate the optical afterglow of a GRB withinseconds of its detection and location by a wide field X-ray imager. It will be mounted onthe Lomonosov spacecraft for launch in 2013 and consists of a coded mask X-ray imager UBATto detect a GRB and estimate a direction vector which will be passed to the SMT opticalsystem which will rotate a moveable mirror to lock onto the GRB and direct the opticalafterglow to a camera with a  ~17′ wide aperture. We present the design geometry ofthe UBAT instrument only, with results of simulations for a range of GRB types to showprobable photon integration times to be expected to extract a significant FOV imagereconstruction and GRB location.

One of the key aspects of the upcoming Ultra-Fast Flash Observatory (UFFO) pathfinder forGamma Ray Bursts (GRBs) identification is the UFFO Burst Alert & Trigger Telescope(UBAT). The scientific propose of UBAT is to detect and locate as fast as possible theGRBs in the sky. This is achieved by using a coded mask aperture camera scheme with a widefield of view (FOV) and selecting a X-ray detector of high quantum efficiency and largedetection area. This X-ray detector of high quantum efficiency and large detection area iscalled the UBAT detector. The UBAT detector consists of 48 × 48 Yttrium Oxyorthosilicate(YSO) scintillator crystal arrays and Multi Anode Photomultiplier Tubes (MAPMTs), analogelectronics equipped with ASIC chips, digital electronics equipped with Field ProgrammableGate Array (FPGA) chips, and a mechanical structure that supports all components of theUBAT detector. The total number of the pixels in the UBAT detector is 2304, and the totaleffective detection area is 191 cm2. We will present the design andconstruction, and performance of the UBAT detector including the responses of the UBATdetector to X-ray sources.

The UFFO (Ultra-Fast Flash Observatory) is a GRB detector on board the Lomonosovsatellite, to be launched in 2013. The GRB trigger is provided by an X-ray detector,called UBAT (UFFO Burst Alarm & Trigger Telescope), which detects X-rays from the GRBand then triggers to determine the direction of the GRB and then alerts the Slewing MirrorTelescope (SMT) to turn in the direction of the GRB and record the optical photon fluxes.This report details the calibration of the two components: the MAPMTs and the YSO crystalsand simulations of the UBAT. The results shows that this design can observe a GRB within afield of view of ±35° and can trigger in a time scale as short as 0.2 – 1.0 safter the appearance of a GRB X-ray spike.

The Ultra-Fast Flash Observatory (UFFO) aims to detect the earliest moment of Gamma-RayBursts (GRBs) which is not well known, resulting into the enhancement of GRB mechanismunderstanding. The pathfinder mission was proposed to be a scaled-down version of UFFO,and only contains the UFFO Burst Alert & Trigger Telescope (UBAT) measuring theX-ray/gamma-ray with the wide-field of view and the Slewing Mirror Telescope (SMT) with arapid-response for the UV/optical photons. Once the UBAT detects a GRB candidate with theposition accuracy of 10 arcmin, the SMT steers the UV/optical photons from the candidateto the telescope by the fast rotatable mirror and provides the early UV/optical photonsmeasurements with 4 arcsec accuracy. The SMT has a modified Ritchey-Chrètien telescopewith the aperture size of 10 cm diameter including the rotatable mirror and the imagereadout by the intensified charge-coupled device. There is a key board called the UFFOData Acquisition system (UDAQ) that manages the communication of each telescope and alsoof the satellite and the UFFO overall operation. This pathfinder is designed and builtwithin the limited size and weight of  ~20 kg and the low power consumption up to ~30 W. We will discuss the design and performance of the UFFO-pathfinder, and itsintegration to the Lomonosov satellite.

The number of experiments on-board Lomonosov spacecraft are preparing now at SINP MSU inco-operation with other organisations. The main idea of Lomonosov mission is to studyextreme astrophysical phenomena, such as cosmic gamma-ray bursts and ultra-high energycosmic rays. These phenomena connect with processes occurred in very distant astrophysicalobjects of the Early Universe and give us information about first stages of Universeevolution. Thus, the Lomonosov mission scientific equipment includes several instrumentsfor gamma-ray burst observation in optics, ultra-violet, X-rays and gamma-rays and thewide aperture telescope for ultra-high energy particle study by detection of ionisationlight along its tracks in the atmosphere. The main parameters and a brief description ofthese instruments are presented.

The study of GRB prompt emission (PE) is one of the main goals of the Lomonosovspace mission, which is being prepared at Moscow State University. The GRBmonitor (BDRG) and the wide-field optical cameras (SHOK) are intended for detection of GRBprompt emission as well as optical counterparts. The BDRG instrument consists of threeidentical NaI(Tl)/CsI(Tl) (13.0 × 2.0cm ) phoswich detectors, whose axes determine theCartesian coordinate system. This allows to localize any GRB source on the sky by means ofthe count rate seen by each detector with an accuracy of ~2 deg. The SHOKinstrument consists of two identical wide-field cameras (WFC) directed in such a way thatthe field of view (FOV) of each WFC overlaps by the corresponding BDRG FOV, which producesa trigger on the WFC in case of a GRB detection. With this setup, the GRB prompt lightcurve will be obtained in the visible without any delay with respect to gamma-rays, whichis crucial for a GRB central engine understanding.

The Slewing Mirror Telescope (SMT) is the UV/optical telescope of UFFO-pathfinder. TheSMT optical system is a Ritchey-Chrétien (RC) telescope of 100 mm diameter pointed bymeans of a gimbal-mounted flat mirror in front of the telescope. The RC telescope has a17 × 17arcmin2 in Field of View and 4.3 arcsec resolution (full width halfmaximum of the point spread function) The beam-steering mirror enables the SMT to access a35 × 35degree region and point and settle within 1 sec. All mirrors were fabricated toabout 0.02 wavelengths RMS in wave front error (WFE) and 84.7% average reflectivity over200 nm ~ 650 nm. The RC telescope was aligned to 0.05 wavelengths RMS in WFE (testwavelength 632.8 nm). In this paper, the technical details of the RC telescope and slewingmirror system assembly, integration, and testing are given shortly, and performance testsof the full SMT optical system are reported.

The Ultra-Fast Flash Observatory (UFFO) Pathfinder for Gamma-Ray Bursts (GRBs) consistsof two telescopes. The UFFO Burst Alert & Trigger Telescope (UBAT) handles thedetection and localization of GRBs, and the Slewing Mirror Telescope (SMT) conducts themeasurement of the UV/optical afterglow. UBAT is equipped with an X-ray detector, analogand digital signal readout electronics that detects X-rays from GRBs and determines thelocation. SMT is equipped with a stepping motor and the associated electronics to rotatethe slewing mirror targeting the GRBs identified by UBAT. First the slewing mirror pointsto a GRB, then SMT obtains the optical image of the GRB using the intensified CCD and itsreadout electronics. The UFFO Data Acquisition system (UDAQ) is responsible for theoverall function and operation of the observatory and the communication with the satellitemain processor. In this paper we present the design and implementation of the electronicsof UBAT and SMT as well as the architecture and implementation of UDAQ.

The Ultra-Fast Flash Observatory (UFFO) is a space observatory for optical follow-ups ofgamma ray bursts (GRBs), aiming to explore the first 60 seconds of GRBs optical emission.UFFO is utilized to catch early optical emissions from GRBs within few sec after triggerusing a Gimbal mirror which redirects the optical path rather than slewing entirespacecraft. We have developed a 15 cm two-axis Gimbal mirror stage for the UFFO-Pathfinderwhich is going to be on board the Lomonosov satellite which is to be launched in 2013. Thestage is designed for fast and accurate motion with given budgets of 3 kg of mass and 3Watt of power. By employing stepping motors, the slewing mirror can rotate faster than 15deg/sec so that objects in the UFFO coverage (60 deg × 60 deg) can be targeted in~1 sec. The obtained targeting resolution is better 2 arcmin using a close-loopcontrol with high precision rotary encoder. In this presentation, we will discuss detailsof design, manufacturing, space qualification tests, as well as performance tests.

The Ultra-Fast Flash Observatory (UFFO), which will be launched onboard theLomonosov spacecraft, contains two crucial instruments: UFFO BurstAlert & Trigger Telescope (UBAT) for detection and localization of Gamma-Ray Bursts(GRBs) and the fast-response Slewing Mirror Telescope (SMT) designed for the observationof the prompt optical/UV counterparts. Here we discuss the in-space calibrations of theUBAT detector and SMT telescope. After the launch, the observations of the standard X-raysources such as pulsar in Crab nebula will provide data for necessary calibrations ofUBAT. Several standard stars will be used for the photometric calibration of SMT. Thecelestial X-ray sources, e.g. X-ray binaries with bright optical sourcesin their close angular vicinity will serve for the cross-calibration of UBAT and SMT.

Gamma-ray bursts (GRBs) triggered by the death of the first stars promise to provide apowerful probe into the state of the high-redshift universe. I will review the basicphysics of how the first stars formed, evaluating whether they are suitable GRBprogenitors. After providing estimates of the high-redshift GRB number density, I willdiscuss the utility of such bursts in probing the ionization state, and the degree ofmetal enrichment, of the early intergalactic medium. The prospects for these studies arebright, provided that we can fly a dedicated mission that combines a gamma-ray detectorwith on-board near-infrared capabilities.

The possibility to divide GRBs in different subclasses allow to understand better thephysics underlying their emission mechanisms and progenitors. The induced gravitationalcollapse scenario proposes a binary progenitor to explain the time-sequence in GRBs-SNe.We show the existence of a common behavior of the late decay of the X-ray afterglowemission of this subclass of GRBs, pointing to a common physical mechanism of their lateemission, consistent with the IGC picture.

Polarimetry is expected to play a major role as a diagnostic tool for GRBs. Techniquesand methods for X/Gamma ray polarimetry are reviewed including the specific problemsrelated to the transient nature of the sources. Optical data do not encourage optimisticpredictions on polarimetry of afterglows. I review some of the existing and proposedexperiments for the prompt and discuss the existing results.

A large majority of GRBs exhibit X-ray emission. In addition, a dedicated separate groupof GRB, the XRFs, exists which emission dominates in the X-ray spectral range. And thethird group of GRB related objects (yet hypothetical) are the group of off-axis observedGRBs (orphan afterglows). These facts justify the consideration of an independentexperiment for monitoring, detection and analyses of GRBs and others fast X-ray transientsin X-rays. We will present and discuss such experiment based on wide-field X-raytelescopes of Lobster Eye type. We show that the wide field and fine sensitivity ofLobster Eye X-ray All-Sky Monitor make such instruments important tools in study ofGRBs.

LOFT (Large Observatory For X-ray Timing) is one of the four candidate missions currentlyunder assessment study for the M3 mission in ESAs Cosmic Vision program to be launched in2024. LOFT will carry two instruments with prime sensitivity in the 2–30 keV range: a 10m2 class large area detector (LAD) with a <1° collimated field of viewand a wide field monitor (WFM) instrument. The WFM is based on the coded mask principle,and 5 camera units will provide coverage of more than 1/3 of the sky. The prime goal ofthe WFM is to detect transient sources to be observed by the LAD. With its wide field ofview and good energy resolution of <500 eV, the WFM will be an excellent instrumentfor detecting and studying GRBs and X-ray flashes. The WFM will be able to detect~150 gamma ray bursts per year, and a burst alert system will enable thedistribution of ~100 GRB positions per year with a ~1 arcmin locationaccuracy within 30 s of the burst.

The small mission A-STAR (All-Sky Transient Astrophysics Reporter) aims to locate theX-ray counterparts to ALIGO and other gravitational wave detector sources, to study thepoorly-understood low luminosity gamma-ray bursts, and to find a wide variety of transienthigh-energy source types, A-STAR will survey the entire available sky twice per 24 hours.The payload consists of a coded mask instrument, Owl, operating in the novel low energyband 4−150 keV, and a sensitive wide-field focussing soft X-ray instrument, Lobster,working over 0.15−5 keV. A-STAR will trigger on ~100 GRBs/yr, rapidlydistributing their locations.