Context. The red dwarf star K2-22 is transited every 9.14 h by an object which is best explained by being a disintegrating rocky exoplanet featuring a variable comet-like dust tail. While the dust is thought to dominate the transit light curve, gas …
Highly-multiplexed Bragg gratings for optically adding spectral lines
Context. The atmospheric and surface characterization of rocky planets is a key goal of exoplanet science. Unfortunately, the measurements required for this are generally out of reach of present-day instrumentation. However, the planet Mercury in our …
Context. Ground-based high-dispersion (R ~ 100 000) spectroscopy (HDS) is proving to be a powerful technique with which to characterize extrasolar planets. The planet signal is distilled from the bright starlight, combining ral and time-differential …
We report the detection of the 2s$^2$2p$^2$$^3$P$_1-->0$ line of Si IX using the McMath-Pierce telescope on Kitt Peak. Observations were made of the solar disk and at various heights above the limb between 2002 May 13 and 17, under nonideal sky …
Recent instrumental developments in imaging polarimetry allow array detectors to reach a polarimetric sensitivity of 1 × 10$^-4$ of the intensity. New instrumental effects appear at these levels of sensitivity and generate spurious polarization …
We present the principles of a new device that combines a high-resolution spectrometer (0.001nm spectral resolution, 10nm bandwidth) with maximum efficiency, a large detector (pixel size 1μm by 1μm, overall size 2cm by 2cm), and a very high density …
Spectroscopic studies of extended astronomical sources at optical wavelengths are hampered by the two-dimensional nature of current photon detectors. Most photons of interest are not utilized because a spectrometer must scan in the spatial or …