The Telescopio Nazionale Galileo (TNG) hosts, starting in April 2012, the visible spectrograph HARPS-N. It is based
on the design of its predecessor working at ESO's 3.6m telescope, achieving unprecedented results on radial velocity
measurements of extrasolar planetary systems. The spectrograph's ultra-stable environment, in a temperature-controlled
vacuum chamber, will allow measurements under 1 m/s which will enable the characterization of rocky, Earth-like
planets. Enhancements from the original HARPS include better scrambling using octagonal section fibers with a shorter
length, as well as a native tip-tilt system to increase image sharpness, and an integrated pipeline providing a complete set
Observations in the Kepler field will be the main goal of HARPS-N, and a substantial fraction of TNG observing time
will be devoted to this follow-up. The operation process of the observatory has been updated, from scheduling
constraints to telescope control system. Here we describe the entire instrument, along with the results from the first
The atmospheres of planets orbiting other stars may be studied by the technique of transit spectroscopy. This technique needs a very high SNR, so large space telescopes are needed, and bright target stars must be found. This paper uses planetary atmosphere models to discuss the SNR performance required to achieve specific science goals for both giant Jupiter-like planets and for small Earth-like planets. It discusses the space telescopes to survey bright stars to find suitable target stars, and the designs of large space telescopes to perform the transit spectroscopy.
We discuss technologies for micro-arcsec echo mapping of black hole accretion flows in Active Galactic Nuclei (AGN). Echo mapping employs time delays, Doppler shifts, and photoionization physics to map the geometry, kinematics, and physical conditions in the reprocessing region close to a compact time-variable source of ionizing radiation. Time delay maps are derived from detailed analysis of variations in lightcurves at different wavelengths. Echo mapping is a maturing technology at a stage of development similar to that of radio inteferometry just before the VLA. The first important results are in, confirming the basic assumptions of the method, measuring the sizs of AGN emission line regions, delivering dozens of black hole masses, and showing the promise of the technique. Resolution limits with existing AGN monitoring datasets are typically approximately 5 - 10 light days. This should improve down to 1 - 2 light days in the next-generation echo mapping experiments, using facilities like <i>Kronos</i> and <i>Robonet</i> that are designed for and dedicated to sustained spectroscopic monitoring. A light day is 0.4 micro-arcsec at a redshift of 0.1, thus echo mapping probes regions 10<sup>3</sup> times smaller than with VLBI, and 10<sup>5</sup> times smaller than with <i>HST</i>.