The planetary nebula M94–20 in the Large Magellanic Cloud was serendipitously observed with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope as part of the Hubble Space Telescope Archival Pure Parallel Program. We present spatially resolved imaging and spectral data of the nebula and compare them with ground based data, including detection of several emission lines f...

pt5m is a 0.5 m robotic telescope located on the roof of the 4.2 mWilliam Herschel Telescope (WHT) building, at the Roque de los Muchachos Observatory, La Palma. Using a five-position filter wheel and CCD detector, and bespoke control software, pt5m provides a high-quality robotic observing facility. The telescope first began robotic observing in 2012, and is now contributing to transient follo...

We present a long range planning (LRP) system, the Spike Plan Window Scheduler, which has been in use for observations on the Hubble Space Telescope (HST) for the past four years and which is being adapted for the Space Infrared Telescope Facility (SIRTF) and Next Generation Space Telescope (NGST) orbiting astronomical observatories. Due to the relatively underconstrained nature of this domain,...

TELESCOPE ENVIRONMENT FOR THE ESO VLT Fionn Murtagh Space Telescope { European Coordinating Facility { European Southern Observatory (A liated to Astrophysics Division, Space Science Department, European Space Agency) and Marc Sarazin European Southern Observatory, D-85748 Garching, Germany November 21, 1995 ABSTRACT We use extensive seeing and low-atmosphere meteorological data obtained at the...

Atmospheric dispersion is a wavelength-dependent effect that affects astronomical observations performed using ground-based telescopes. The of atmospheric for 4-meter telescope analyzed and an corrector (ADC) system was designed its adaptive optical system. With the help line fit method, science images can be conveniently used to measure control ADC correct dispersion, thus full-width at half-m...

Ultrashort, high-power laser pulses propagating vertically in the atmosphere have been observed over more than 20 km using an imaging 2-m astronomical telescope. This direct observation in several wavelength bands shows indications for filament formation at distances as far as 2 km in the atmosphere. Moreover, the beam divergence at 5 km altitude is smaller than expected, bearing evidence for w...

The effects of atmospheric differential refraction on astronomical measurements are much more important than is generally assumed, In particular, it is shown that relative line and coritinuum intensities in spectrophotometric work may be erroneous if this phenomenon is neglected, To help observers minimize these errors, the relation between object position and optimal slit or aperture orientati...

The new astronomical technique of gravitational microlensing enables measurements of high precision to be made in certain circumstances. Useful advances have been made in the fields of galactic astronomy, stellar astronomy and planetary science. The technique is best suited to the southern sky, and several observations have been made from Australasia. A sample of these observations is described...

PALM-3000 is proposed to be the first visible-light sodium laser guide star astronomical adaptive optics system. Deployed as a multi-user shared facility on the 5.1 meter Hale Telescope at Palomar Mountain, this state-of-the-art upgrade to the successful Palomar Adaptive Optics System will have the unique capability to open the visible light spectrum to diffraction-limited scientific access fro...

Current optical interferometers are affected by unknown turbulent phases on each telescope. In the field of radio-interferometry, the self-calibration technique is a powerful tool to process interferometric data with missing phase information. This paper intends to revisit the application of self-calibration to Optical Long Baseline Interferometry (OLBI ). We cast rigorously the OLBI data proce...