Previous Article Next Article Table of Contents
Infrared Tools for Solar Astrophysics: What's Next? (1Dec94) (from NSO, NOAO Newsletter No. 40, 1 December 1994) An extremely varied group of scientists attended the 15th Annual NSO/Sac Peak Workshop. The goal of the workshop was to investigate new ways that infrared tools can be used to study the Sun, and to see where the major future efforts should be. Studying the solar corona at infrared wavelengths is a new application; this was discussed at length during the first two days. After solid reviews of the current state of coronal heating theories (Zirker and Cargill), exciting optical observations of interacting coronal loops (Airapetian) and coronal density variations (November) were presented. Infrared line calculations were discussed by Chang and Castner: a new prediction of a forbidden Fe XII line near 2 um (Chang), and a chromospheric O II emission at 1.1 um (Castner). Penn reviewed new efforts to measure such lines, concentrating on new observations of the Fe XIII line pair at 1.1 um and the Si X line at 1.4 um. Several speakers discussed the IR camera systems that are in current use by commercial or astronomical users, after which several speakers showed how such detectors are being used in scientific instruments. Kuhn discussed new measurements of the coronal magnetic field. Simons reviewed an operating imaging FFT spectrometer and showed results of studies of planetary nebula. Jones discussed the new NSO/Kitt Peak He I 1083 nm narrow-band filter system, which promises exciting new views of the chromospheric magnetic field. Several night-time astronomers were invited to summarize the infrared coronagraphic science currently being done with post-focus coronagraphs. Jewitt reviewed recent work on the well-known dust disk around þ Pictoris. Fort reviewed new techniques for finding dark matter concentrations by using the lensing effects such concentrations have on the distant background of blue galaxies. Finally, Morgan discussed solar system observations using true coronagraphs; he has investigated the lunar atmosphere and suggests that the Mercurian atmosphere is another good target. Ayres discussed new observations of the CO molecule in the solar atmosphere. Schmidt presented new time-series observations of sunspot magnetic fields which show that oscillations in the magnetic field intensity, if they exist at all, must be at a very low level. Chromospheric oscillations using the He I 1083-nm absorption line were discussed by Bocchialini and Fleck. Ruedi presented new measurements of the chromospheric magnetic field and compared them with simultaneous photospheric observations to measure the vertical gradient of the field. The last day of the workshop was devoted to a discussion of the scientific uses for a large reflecting coronagraph. Workshop participants had earlier submitted mock observing proposals for a proposed 2-4m reflecting coronagraph; these proposals served as a basis for discussion about the science that could be done with such an instrument. Significant solar science led the discussion, from multi-wavelength observations of solar flux tubes on the disk to direct and detailed measurements of the coronal magnetic field. Planetary applications for such a telescope seem to abound, from weak planetary atmospheres to asteroid and comet observations. Also, such a telescope appears to be useful for some gravitational lensing questions. The plethora of scientific applications proposed for a large reflecting coronagraph suggests that it would certainly operate 24 hours a day. Matt Penn, Jeff Kuhn
Previous Article Next Article Table of Contents