The Atmospheric Imaging Assembly (AIA) provides multiple simultaneous highresolution full-disk images of the corona and transition region up to 0.5 R above the solar limb with 1.5-arcsec spatial resolution and 12-second temporal resolution. The AIA consists of four telescopes that employ normal-incidence, multilayer-coated optics to provideThe Solar Dynamics Observatory

The Interface Region Imaging Spectrograph (IRIS) small explorer spacecraft provides simultaneous spectra and images of the photosphere, chromosphere, transition region, and corona with 0.33 -0.4 arcsec spatial resolution, two-second temporal resolution, and 1 km s −1 velocity resolution over a field-of-view of up to 175 arcsec × 175 arcsec. . IRIS is sensitive to emission from plasma at temperatures between 5000 K and 10 MK and will advance our understanding of the flow of mass and energy through an interface region, formed by the chromosphere and transition region, between the photosphere and corona. This highly structured and dynamic region not only acts as the conduit of all mass and energy feeding into the corona and solar wind, it also requires an order of magnitude more energy to heat than the corona and solar wind combined. The IRIS investigation includes a strong numerical modeling component based on advanced radiative-MHD codes to facilitate interpretation of observations of this complex region. Approximately eight Gbytes of data (after compression) are acquired by B. De Pontieu (B) ·Harvard-Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138, USA

The X-ray Telescope (XRT) of the Hinode mission provides an unprecedented combination of spatial and temporal resolution in solar coronal studies. The high sensitivity and broad dynamic range of XRT, coupled with the spacecraft’s onboard memory capacity and the planned downlink capability will permit a broad range of coronal studies over an\ud extended period of time, for targets ranging from quiet Sun to X-flares. This paper discusses in detail the design, calibration, and measured performance of the XRT instrument up to the focal plane. The CCD camera and data handling are discussed separately in a companion paper

No abstract

We describe a high-throughput optical spectrograph that has been in operation at the Cassegrain focus of the 1.5-m Tillinghast reflector since 1994 January. FAST has a 3Ј-long slit and is typically operated at resolutions between 1 and 6 Å . With a collimated beam diameter of ∼100 mm, FAST (with a 300 lines mm Ϫ1 grating and a 1Љ .5-wide slit) offers 4000 Å of spectral coverage at 3 Å resolution. FAST's optics are primarily reflective, are adequately sized to prevent vignetting, and use high-performance coatings. The high measured system peak efficiency of 26% (fraction of light incident on the primary detected at the CCD) demonstrates that the throughput of reflective optics can be quite competitive with that of refractive optics. FAST's structure is constructed from graphite-epoxy composite panels, which have an excellent stiffness-to-weight ratio and low thermal expansion, resulting in low flexure and excellent focus stability.