Found 3 talks width keyword flare stars
Meeting ID: 868 2664 6040
On the Sun, the presence of magnetic flux at the photosphere is closely linked to (1) steady heating of the overlying atmosphere and (2) transient brightenings, the largest of which are flares. I will discuss statistical properties of both phenomena, with an emphasis on aspects of each that might apply to other astrophysical objects, such as other stars or stellar remnants, and perhaps AGNs. Regarding heating, power-law scalings have been found to relate magnetic flux with steady coronal emission in both soft X-ray (SXR) and EUV ranges. A key observation is that the details of magnetic structure (field strengths and their spatial gradients, including measured electric currents) appear not to affect heating rates. Similar SXR scalings have been reported for G,K, and M dwarfs and classical T-Tauri stars. Departures from such scalings, whether on the Sun, other stars, or other objects, might reveal important aspects of the heating mechanisms that drive steady emission, and should be sought. Regarding flaring, again a power-law scaling between magnetic flux and flare SXR emission has been found, but with a different exponent. Differences in these scalings suggest that steady heating fundamentally differs from flare heating, disfavoring the “nanoflare” hypothesis (i.e., that steady coronal heating arises from many weak, unresolved flares that are essentially scaled-down versions of larger flares). Analogous differences in the scalings of steady vs. flaring luminosities with magnetic flux on other objects could constrain processes driving each type of emission. Another key property of flares is that they extract energy from the magnetic field, which in the solar case leads to measurable changes in field strengths after flares – photospheric field strengths tend to increase, coronal fields tend to decrease. It is possible that analogous changes could be observed on other stars or objects (via, e.g., Zeeman or synchrotron methods).
AbstractThe 3.8m optical and infrared telescope, which is Japan's first segmented mirror telescope, is now being constructed using the world's first super high precision, high speed grinding technology and the world's first truss structure drive system. This is the joint project between Kyoto University, Nagoya University, National Astronomical Observatory, and Nano-Optonics Energy (private company) with the budget of the Nnao-Optonics Energy and Dr Hiroshi Fujiwara (CEO of the Nano-Optonics Energy). The telescope will be completed in 2012 and installed in Okayama, and will become the biggest optical and infrared telescope in east Asia. The technologies for making this telescope such as (1) grinding technology, (2) segmented mirror, and (3) truss structure drive system are also basic technologies for the future extremely large telescope such as the 30m telescope. The scientific objective of the telescope is the search for the transient objects (gamma ray bursts, black hole binaries, stellar flares) and the extra solar planets. How this project has emerged and developed will be discussed in detail, including also the discussion about the possible future international collaboration.
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