Journey into space

James Machell, Chris Tallon and Dan Hedges outline the particular objectives and achievements of the Bradford Robotic Telescope.     

Digging for SALT

Mark Bailey reports from South Africa on the ground-breaking ceremony for the Southern African Large Telescope on 1 September 2000.     

Beyond Einstein NASA office

At the Paris Air Show in June, NASA and ESA formally signed their agreement to work on the James Webb Space Telescope.     

Refinements and revelations

Peter Bond summmarizes recent discoveries about Martian radiation, possible new forms of matter and a sooty black comet – not to mention the nearly new Hubble Space Telescope.     

Telescope400 at Syon Park

Teresa Grafton, on behalf of the Telescope400 Committee, reports on the successful celebration of 400 years since Thomas Harriot's lunar observations, an IYA2009 event that appealed to young and old.     

Spitzer: the first 30 months

In his George Darwin Lecture, Michael Werner celebrates the achievements of the Spitzer Space Telescope, an observatory that owes much of its success to the fact that it is cool by design.     

The Bullerwell Lecture 2008

A new adaptive optics system at the Palomar Observatory makes use of random atmospheric fluctuations to get high-resolution astronomical images from the surface of the Earth – twice as sharp as Hubble Space Telescope images.     

Solar system summer

It's one thing to picture weather on other planets in the solar system, quite another to get any idea of conditions on planets orbiting other stars, but that is what researchers using the Spitzer Space Telescope have done.     

Global telescope networks for astronomy education

Ever wanted to give school students or the public a closer look at the stars, without worrying about the vagaries of the UK weather? Paul Roche and Rachel Dodds from the Faulkes Telescope Project explain how you can do just that – without even leaving the classroom!     

GAMA: towards a physical understanding of galaxy formation

Simon P Driver, Peder Norberg, Ivan K Baldry, Steven P Bamford, Andrew M Hopkins, Jochen Liske, Jon Loveday, John A Peacock and the GAMA Survey Team (Galaxy and Mass Assembly) review progress on the latest large galaxy redshift survey now underway on the 3.9 m Anglo-Australian Telescope.     

Possibilities for the application of adaptive optics at solar telescopes

Possibilities for the application of adaptive optics at solar telescopes are studied. A modified correlation tracker to measure the image motion at the first focus of the Big Solar Vacuum Telescope (BSVT) at the Baikal Astrophysical Observatory of the Institute for Solar-Terrestrial Physics, the Siberian Branch of the Russian Academy of Sciences, has been investigated experimentally.     

Sigmoid CME source regions at the Sun: some recent results

Identifying coronal mass ejection (CME) precursors in the solar corona would be an important step in space weather forecasting, as well as a vital key to understanding the physics of CMEs. Twisted magnetic field structures are suspected of being the source of at least some CMEs. These features can appear sigmoid (S or inverse-S) shaped in soft X-ray (SXR) images. We review recent observations of these structures and their relation to CMEs, using SXR data from the Soft X-ray Telescope (SXT) on the Yohkoh satellite, and EUV data from the EUV Imaging Telescope (EIT) on the SOHO satellite. These observations indicate that the pre-eruption sigmoid patterns are more prominent in SXRs than in EUV, and that sigmoid precursors are present in over 50% of CMEs. These findings are important for CME research, and may potentially be a major component to space weather forecasting. So far, however, the studies have been subject to restrictions that will have to be relaxed before sigmoid morphology can be used as a reliable predictive tool. Moreover, some CMEs do not display a SXR sigmoid structure prior to eruption, and some others show no prominent SXR signature of any kind before or during eruption.     

The story of galaxy evolution in full colour

A Holy Grail of modern astronomy is understanding the origin of Edwin Hubble's morphological sequence of galaxy types. What made some collapsing gas clouds turn into elegant spiral systems like our own Milky Way, whereas others became smooth, featureless ellipticals? More fundamentally, does the taxonomic scheme introduced by Hubble in the 1920s have any physical relevance? The Space Telescope that bears Hubble's name is providing answers to these and other questions in the context of modern theories of structure formation.
Richard S Ellis, Roberto G Abraham, Jarle Brinchmann and Felipe Menanteau show how modern telescopes producing colourful images are pointing the way to understanding galaxy evolution.     

硬X射线调制望远镜直接解调成像方法快速实现

针对硬X射线巡天望远镜具有的18个探测器的设计,本文给出了直接解调成像方法快速实现的两个途径。一是根据点扩展函数值中有大量零元的事实,给出了基于点扩展函数值的非零元的Lucy迭代计算和存储方法：二是将直接解调成像方法中Lucy迭代改为观测数据按一定方式分组排序的Lucy迭代。数据实验表明,本文方法大幅度提高了直接解调成像的速度。     

Observations of interplanetary scintillation during the 1998 Whole Sun Month: a comparison between EISCAT, ORT and Nagoya data

Observations of interplanetary scintillation (IPS) allow accurate solar wind velocity measurements to be made at all heliographic latitudes and at a range of distances from the Sun. The data may be obtained with either single, double or multiple antennas, each requiring a different method of analysis. IPS data taken during the 1998 whole sun month (30th July–31st August 1998) by EISCAT, the ORT (Ooty Radio Telescope), India, and the Nagoya IPS system, Japan, allow the results of individual methods of analysis to be compared. Good agreement is found between the velocity measurements using each method, and when combined an improved understanding of the structure of the solar wind can be obtained.On leave from the Physical Research Laboratory, Ahmedabad 380 009, India     

Observations of the solar radio emission with the Callisto spectrometer

In the framework of the program for setting the Callisto spectrometer network into operation, the spectral measurements were carried out at the sites of spectrometer locations in India and Russia in winter 2006. The results achieved at Badary, the site where the Siberian Solar Radio Telescope (SSRT) is located, are presented. The measurements were performed using a broadband log-periodic antenna connected to the Callisto spectrometer developed at the Institute of Astronomy (Zurich). The results of these measurements should explain whether spectral studies at frequencies below 1 GHz can be performed using such antennas or new antennas should be developed. The presented results are compared with the similar results obtained in Switzerland in the frequency intervals of interest for radio astronomy. Concerning electromagnetic noise, Badary is a better site for observing the Sun in the 50–800 MHz frequency range as compared to observatories in Switzerland.     

ULYSSES observations of energetic particle acceleration and the superposed CME and CIR events of November 1992

During November 1992, a series of forward and reverse shocks passed the ULYSSES spacecraft. Spectral and anisotropy measurements are reported for protons and alpha particles between 0.28 and 6 MeV observed by the Energetic Particle Composition Experiment, data recorded by the Magnetometer Experiment and the high-energy (2.7-300 MeV) proton data from the Kiel Electron Telescope. An analysis of energetic particle, plasma and magnetometer data from ULYSSES has allowed a unique study of the corresponding arrival of fare particles, particles within a corotating interaction region and particles transported with a coronal mass ejection. We present an analysis of these data in terms of possible diffusive shock acceleration but conclude that this is likely to be incompatible with the short transit time of the particles. Shock drift acceleration of particles with energies 0.3 MeV/nucleon or solar acceleration followed by particle trapping behind the shock front are alternative possibilities.     

Diagnostics of turbulent and fractal properties of photospheric plasma outside active regions of the Sun

Results of analysis of multi-scale and turbulent properties of observed photospheric granulation patterns in undisturbed solar photosphere are presented. Data were obtained with the New Solar Telescope at Big Bear Solar observatory. Different types of magnetic environment were explored: a coronal hole (CH) area, a quiet sun (QS) intranetwork area, a QS/network area, and an area with small pores. The property of multifractality was revealed for granulation patterns in all environments on scales below 600 km. The degree of multifractality tends to be stronger as the magnetic environment becomes weaker. Analysis of turbulent diffusion on scales less than 1000–2000 km revealed the regime of super-diffusivity for all data sets. Super-diffusion becomes stronger from the QS/network to the QS/intranetwork to the CH. Both multifractality and super-diffusivity on very small scales are associated with the fast turbulent dynamo action. The results show that the most favorable conditions for the fast turbulent dynamo are met outside the network, inside vast areas of weakest magnetic fields, which supports the idea of nonlocal, deep turbulent dynamo.     

Studying the solar corona above active regions from microwave observations during solar flares recorded by CORONAS-F satellite

In 2001–2003, 45 flares of hard X ray (HXR) and gamma ray radiation, identified with a particular active region (AR) that produced each event, were recorded during the experiments onboard the Russian Solar Observatory CORONAS-F using the SONG (solar neutrons and gamma ray quanta) instrument. The solar corona structure and dynamics above these ARs is studied on the basis of the microwave observations with two Russian radio telescopes RATAN-600 and Siberian Solar Radio Telescope (SSRT). The results are illustrated using the active region NOAA 9601 and flare of September 5, 2001 (～ 1430 UT) as an example. The flare is interesting because the energy of its gamma radiation exceeded 1 MeV, while its power was only M6.0 in soft X rays. Such a combination of the event characteristics is not too frequent, which indicates that the spectrum of the studied event was rather hard. The type of the source of microwave radiation above NOAA 9601 has been determined. Some properties of this-type sources of a diagnostic value for detecting ARs capable of producing HXR and gamma radiation are indicated.     

The vorticity of Solar photospheric flows on the scale of granulation

We employ time sequences of images observed with a G-band filter (λ4305Å) by the Solar Optical Telescope (SOT) on board of Hinode spacecraft at different latitude along solar central meridian to study vorticity of granular flows in quiet Sun areas during deep minimum of solar activity. Using a feature correlation tracking (FCT) technique, we calculate the vorticity of granular-scale flows. Assuming the known pattern of vertical flows (upward in granules and downward in intergranular lanes), we infer the sign of kinetic helicity of these flows. We show that the kinetic helicity of granular flows and intergranular vortices exhibits a weak hemispheric preference, which is in agreement with the action of the Coriolis force. This slight hemispheric sign asymmetry, however, is not statistically significant given large scatter in the average vorticity. The sign of the current helicity density of network magnetic fields computed using full disk vector magnetograms from the Synoptic Optical Long-term Investigations of the Sun (SOLIS) does not show any hemispheric preference. The combination of these two findings suggests that the photospheric dynamo operating on the scale of granular flows is non-helical in nature.