Archivi tag: stars

Making ‘your own’ Universe at home

An image of a simulated cluster of galaxies captured when the Universe was half its present age, as seen through the TAO virtual telescope module. Credit: TAO

La Swinburne University of Technology ha ideato un programma virtuale di astronomia che permetterà agli scienziati di ricostruire una serie di visualizzazioni complesse, e a piacere, dell’Universo. Tutto ciò si potrà fare da casa con il proprio computer.

The Theoretical Astrophysical Observatory (TAO), funded by the Australian Government’s $48 million NeCTAR project, draws on the power of Swinburne’s gSTAR GPU supercomputer to allow astronomers to simulate the Universe and see how it would look through a wide range of telescopes. “TAO lets researchers take the data from massive cosmological simulations and map it onto an observer’s viewpoint, to test theories of how galaxies and stars form and evolve”, TAO project scientist, Swinburne Associate Professor Darren Croton, said. “TAO makes it easy and efficient for any astronomer to create these virtual universes. It’s the culmination of years of effort that is now at the fingertips of scientists around the world. Using TAO it might take a few minutes to create a mock catalogue of galaxies, versus months or even years of development previously“. Swinburne worked with eResearch company Intersect Australia Ltd, who designed the web interface with simplicity and user-friendliness in mind. Associate Professor Croton said that “it was important to create a service that could be used by any astronomer regardless of their area of expertise, because that accelerates the pace of science and boosts the chance of breakthroughs”. As new survey telescopes and instruments become available, they can be modelled within TAO to maintain an up-to-date set of observatories. “TAO could be especially useful for comparing theoretical predictions against observations coming from next-generation survey telescopes, like the Australian Square Kilometre Array Pathfinder (ASKAP) in Western Australia, and the SkyMapper Telescope run by the Australian National University (ANU). These will cover large chunks of the sky and peer back into the early stages of the Universe and are tasked with answering some of the most fundamental questions know to humankind”.

Swinburne University: Creating virtual universes with Swinburne's Theoretical Astrophysical Observatory

Third BCool Meeting

According to dynamo models, the variable magnetic field of the Sun is the consequence of the interplay between two main ingredients. The first ingredient is the radial and latitudinal differential rotation that succeeds at generating a large-scale toroidal magnetic field from an initial poloidal field. The second ingredient is still a matter of debate, with models invoking either the cyclonic convection in the convection zone or the transport of decaying active regions by meridional circulation as possible processes to regenerate the poloidal magnetic component. When acting together, both effects succeed at building continuously a large-scale magnetic field that oscillates with time, giving rise to the 22 yr period of the solar cycle. Despite considerable progress in this field since the very first solar dynamo models, there are still many aspects of solar magnetism that the current models cannot reproduce or did not thoroughly explore.

Our understanding of the solar dynamo can benefit from the observation of solar-type stars, where dynamo types marginal or inactive in the Sun can be observed, either because these analogues of the Sun are caught by chance in an unfrequented activity state (similar, e.g., to the Maunder minimum) or because their physical properties (in particular their mass and rotation rate) differ sufficiently from the Sun’s to lead to a different dynamo output. Using spectropolarimetric observations, the magnetic fields of cool stars can now be directly characterized from the polarized signatures they produce in spectral lines, and the associated field geometries can be reconstructed using tomographic imaging techniques, like Zeeman-Doppler-Imaging.

More info: http://bcool2014.sciencesconf.org/

Astronomy in the TMT Era

TMT-J invites you to join us for a two-day workshop “Astronomy in the TMT Era” in Tokyo, Japan to explore the potential of TMT in astronomy. TMT is an international project to build and operate a 30 meter telescope located on Mauna Kea. The program will consist of talks and discussions exploring TMT science with first-light and future instruments. We anticipate a broad range of topics on new results, new interpretation and theory, discussing with clear implication the best usage of TMT “in the TMT era”. The second half of Day 2 will focus on the 2nd generation instruments, which will further bring exciting TMT capabilities to meet diverse scientific needs. Each section will open with one or two invited reviews, followed by contributed talks. This workshop followed by the TMT SAC meeting on Oct. 18. is an opportunity to bring together the Japanese astronomical community to the TMT project and promote the development of international collaborations of science and instrumentation.

Topics:

  • – Cosmology
  • – Galaxy formation & evolution, AGN
  • – Nearby galaxies
  • – Stars, exoplanets & star formation
  • – Time domain & polarimetry sciences
  • – 2nd generation instrumentation

Massive Stars: From alpha to Omega

The ‘Massive Stars’ meetings (poster) have enjoyed more than 40 years of startling success since the first meeting in Argentina in 1971. Held every 4 to 5 years, these meetings aim to encapsulate the current state-of-the-art of our understanding of the physics of Massive Stars and their role in the Universe. For this 10th meeting in the Massive Stars series the Institute of Astronomy, Astrophysics, Space Applications and Remote Sensing of the National Observatory of Athens, invites you to the island of Rhodes, once home to one of the greatest astronomers of antiquity, Hipparchos, who is generally acknowledged as the founder of trigonometry, discoverer of precession and publisher of the first star catalog around 135 BC.

The conference will build on results from ongoing large-scale multi-wavelength surveys of massive stars which are being coupled with new theoretical advances dealing with stellar evolution and the processes which affect that evolution: mass-loss, rotation, convection, magnetic fields, multiplicity and environment. It will tackle important problems from birth, through main sequence evolution and until core collapse. There will be a strong focus on relating the major theoretical uncertainties afflicting stellar evolution through these phases to the current observational picture. The impetus for this focus is derived from the realization that our understanding of massive star evolution is severely challenged by new observations powered largely by technological advances in telescopes and instrumentation. This has enabled new ways of looking at old long-standing problems enabling large-scale high-quality surveys of resolved stellar populations. As theoretical approaches try to keep pace with this increase in information the cracks in our assumptions concerning stellar evolution have become more apparent, even glaring. Whereas before it might have been possible to understand some of the stars some of the time it is now clear that understanding stellar populations is a considerable challenge and will require substantial efforts to resolve. This is an exciting time as observations have revealed large gaps in understanding of the formation and evolution of massive stars. The huge impact that massive stars have on their immediate environment, parent galaxies, and through the Universe, demands better understanding of massive star evolution from alpha to Omega.

CASCA 2013

The Canadian Astronomical Society (CASCA) will be having its annual meeting for 2013 at the University of British Columbia in Vancouver, BC, hosted by UBC Physics & Astronomy. The conference runs Tuesday May 28 through Thursday May 30. There is no specific theme for this CASCA meeting but it will feature new and exciting results from many areas of astronomical research!! Everyone is welcome. There will be general sessions on solar system, compact objects, stars, ISM, galaxies, instrumentation and education. General conference information (including the schedule, maps, restaurant information, and more) is available for download here. Your conference package will contain a hard copy of a shortened version of this document

New advances in stellar physics

This meeting aims to gather stellar astrophysicists interested in microscopic and macroscopic processes in stars, and throw new light on their interdependence and consequences for stellar structure and evolution. Stellar modelling is faced with the drastic improvement of observational data, including precise spectroscopy, astrometry, interferometry and asteroseismology. In this context, it is important to recognize that the chemical abundances observed in stellar surfaces are not the original ones, and that they continuously evolve inside stars, with important consequences on the stellar structure.

This meeting is in honour of Sylvie Vauclair, who has devoted a large part of her scientific career to the study of both microscopic and macroscopic processes in stars. She was among the first few astrophysicists during the 70’s who were involved in the fruitful scientific adventure of considering diffusion processes in chemically peculiar stars, and she opened further important directions of research. She also has had a prominent role in teaching physics in Paris and Toulouse universities, and in supervising a number of PhD students. She is deeply involved in popularizing astrophysics through numerous media.

Fifty Years of Seismology of the Sun and Stars

In the last 50 years, helioseismology has made significant contributions to the knowledge of the Sun’s interior physics and has led the way to asteroseismology. We have now reached an era where more sophisticated questions are being asked to understand the subtle properties of the Sun and other stars due to the synoptic and high-resolution observations available from BISON, GONG and space missions such as SOHO, SDO, CoRot and Kepler. On this occasion, a workshop on the theme of “Fifty Years of Seismology of the Sun and Stars” is being organized to discuss the advances, reflect on the progress that has been made, and address new challenges. We plan to bring together helio- and asteroseismologists, theorists and observers in a journey that will take us from the interior of the Sun and its magnetism towards the structure of distant stars and activity cycles.

Topics include:

  • Historical perspective
  • Advances in observational technique
  • Solar structure and dynamics
  • Stellar activity and variability
  • Local helioseismology and helioseismic imaging
  • Numerical simulations of convections and waves
  • Seismology of the solar atmosphere
  • Requirements for future instrumentation
  • Prospects for future missions

The Next Generation CFHT: A 10m, Wide-Field, Spectroscopic Telescope for the Coming Decade

For over 30 years the Canada-France-Hawaii Telescope and its international community have developed innovative capabilities to support advanced research. CFHT was among the first on Mauna Kea to develop a facility class adaptive optics system, multi-object and integral field spectrographs, and wide field panoramic imagers. Today we look to a future that builds upon our past, including the possibility of replacing the current 3.6 m telescope with a 10 m facility dedicated to wide field spectroscopy. If pursued, the next-generation CFHT (ngCFHT) would re-use the existing facility except for the telescope and dome, which would be replaced. While this concept is in infancy from a technical development perspective, considerable work has been completed in defining the science objectives for such a facility and we look forward to hosting members of the international astronomy community in Hawaii to discuss ngCFHT.

More information on ngCFHT is available at: The Next Generation CFHT, A Study