The SX Phe stars

A systematic photometry study of SX Phe stars together with high amplitude Sct stars have been carried out. Theuvbyß indices are obtained and the physical parameters are determined. The results obtained by using the pulsation and evolution theories independently are compared. A good agreement is found.Partially based on observations collected at European Southern Observatory, La Silla, Chile and by using the 1.5 m telescope from the Observatorio Astronómico Nacional (I. G. N.) at Calar Alto Observatory, Almería, Spain.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

Ultraviolet to near-infrared continuum flux distribution in the active binary RS canum venaticorum

We present multifrequency observations of the active binary RS CVn. Ultraviolet observations were obtained from the IUE data bank. Optical observations were made at the Observatorio del Roque de los Muchachos (La Palma), while the infrared observations were obtained at the Observatorio del Teide (Tenerife).The continuum of RS CVn shows that both components behave in good agreement with normal values for their spectral type and luminosity class, when observed data are corrected for small spot effects. No significant circumstellar reddening is detected.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

NGC 985: Interactions and the origin of AGNs

Observations of the Seyfert galaxy NGC 985 have revealed large-scale extended ionized zones, covering a large fraction of the ring-shaped structure of this galaxy. These ionized regions are a major contributor to the total far-infrared emission of this object. An interaction driven starburst is proposed to explain the main features of this galaxy.Based on observations obtained at the Observatorio de El Roque de los Muchachos, La Palma, Spain.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

The CMC15, the last issue of the series “Carlsberg Meridian Catalogue,La Palma”

CMC15 is the last of the series “Carlsberg Meridian Catalogue, La Palma” and comprises all the observations made between March 1999 and March 2011 with the Carlsberg Automatic Meridian Circle in El Roque de los Muchachos Observatory on the island of La Palma (Spain). The catalogues CMC12, CMC13, and CMC14 are superseded by this one. It contains more than 122 million observations of right ascension, declination, and magnitude of stars in the magnitude range of 9^m < r′ < 17^m and declination range of –40° < δ < +50°. The catalogue internal errors in astrometry are below 30 mas in both coordinates for stars brighter than r′ = 13, reaching 60 mas for r′ = 16. The internal magnitude error is below 0.020 mag for stars brighter than r′ = 13, and about 0.090 mag for r′ = 16. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Photometry and spectroscopy of the solar granulation along the polar axis and equator

From high-resolution CCD images of granulation obtained at the Swedish Solar Tower of the Observatorio del Roque de los Muchachos at different positions on the solar disk, mean bi-dimensional spatial power spectra have been obtained at each position and restored following the method proposed by Rodríguez Hidalgoet al. (1990). The variation with latitude of the power spectrum, of the granular brightness contrast and of the mean wave number of the power spectrum are presented. The analysis is completed with spectroscopic observations obtained at the Gregory Coudé Telescope of the Observatorio del Teide. The centre-to-limb and latitudinal variation of the bisectors, residual intensities and equivalent widths are shown for several photometric lines.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

The tidal origin of angular momentum in galaxies

We present the results of numerical simulations of relaxing protogalaxies under the tidal action of other similar systems and also clusters of galaxies. It is found that the bimodal behaviour of the observed angular momentum of galaxies can be explained under the assumption of different initial dynamical conditions induced by the evolving structure of the Universe expected in the adiabatic picture.Observatorio Astronómico, Córdoba, Argentina.CONICET, Buenos Aires, Argentina.     

The Hei D 3 5876 Å line as an activity and structural indicator in F-type Hyades stars

We give the first results of a study in F-type MS stars using the Hei D ₃ absorption feature at 5876 Å as an indicator of stellar activity and structure. The observations were obtained with the QUB echelle spectrograph at the Cassegrain focus of the 4.2 m William Herschel telescope, and have spectral resolution /6×10⁴, and signal-to-noise ratios 200. We chose as a first sample 17 F-stars of the Hyades Main Sequence. It was found that Hei D ₃ and X-ray emission appear aroundB-V 0.3, indicating the onset of sub-surface convection zones. Below this value, in stars withB-V0.42–0.44 the behaviour of the Hei D ₃ equivalent width against Rossby number is different from that observed in later type stars, indicating that the presence of nonradiative mechanisms other than dynamo must be important in heating the chromospheres of these hotter stars.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.Based on observations made with the William Herschel telescope, operated on the island of La Palma by the Royal Greenwich Observatory, in the Spanish Observatorio del Roque de Los Muchachos of the Instituto de Astrofisica de Canarias.     

Fried's parameter derived from observations of granulation outside the disk centre

A new method has recently been developed to obtain the Fried's parameter from observations of granulation outsude the disk centre, based on the different degradation suffered by the images on the directions parallel and perpendicular to the solar limb, due to the geometrical foreshortening. This procedure has been applied to CCD images obtained at the Swedish Solar Tower of the Observatorio del Roque de los Muchachos, with satisfactory results which are presented and discussed.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

Auvbyβ survey for Ca II emission stars

During the last two years auvby photometric survey of 85 Ca II emission stars from the Mount Wilson program on stellar activity has been carried out at the Calar Alto Observatory (Almeria, Spain). We present preliminary results for theuvby and calibrations. Some stars displaying anomalousc ₁ andm ₁ indices, with photometric or spectroscopic data from previous studies, are reported. A reddening study for the complete sample is given.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

The XMM-Newton Bright Serendipitous Survey: First Extragalactic Results

We present here some initial results from the ongoing XMM-Newton bright serendipitous survey. The survey is aimed at selecting and spectroscopically identifying a large and statistically representative sample of bright (f _x ≳ 7× 10⁻¹⁴ c.g.s) serendipitous X-ray sources in the 0.5–4.5 keV energy band (BSS) and a complementary (smaller) sample in the 4.5–7.5 keV energy band (HBSS). The work is partly based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributors directly founded by ESA member states and the USA(NASA) and on observations collected at TNG. The TNG telescope is operated on the island of La Palma by the Centro Galileo Galilei of the INAF in the Spanish Observatorio del Roque de Los Muchachos of the Instituto de Astrofísica de Canarias. On behalf of the XMM-Newton Survey Science Center.     

An Optical Intermediate Dispersion Spectrograph for the GTC

ODIN is an international consortium constituted to design and build a first-light multi-purpose optical intermediate dispersion spectrograph for the Gran Telescopio Canarias (GTC, 10-m) to be installed at the Observatorio del Roque de los Muchachos (La Palma). This instrument should fulfill an important fraction of the needs of the Spanish astronomical community in optical spectroscopy performed at large telescopes, and must be highly competitive in a variety of research fields. We are proposing a spectrograph that will be capable of providing multi-object observations by means of optical fibers, integral field spectroscopy, and also multi-integral fields. It will be mounted at the Nasmyth focus of the GTC. One of the main drivers of our proposal is to cover the whole visible range allowed by the atmospheric cut-off with the highest efficiency, particularly at the UV end. This revised version was published online in July 2006 with corrections to the Cover Date.     

Automatic Solar Flare Detection Using Neural Network Techniques

We present a new method for automatic detection of flare events from images in the optical range. The method uses neural networks for pattern recognition and is conceived to be applied to full-disk Himages. Images are analyzed in real time, which allows for the design of automatic patrol processes able to detect and record flare events with the best time resolution available without human assistance. We use a neural network consisting of two layers, a hidden layer of nonlinear neurodes and an output layer of one linear neurode. The network was trained using a back-propagation algorithm and a set of full-disk solar images obtained by HASTA (HSolar Telescope for Argentina), which is located at the Estación de Altura Ulrico Cesco of OAFA (Observatorio Astronómico Félix Aguilar), El Leoncito, San Juan, Argentina. This method is appropriate for the detection of solar flares in the complete optical classification, being portable to any Hinstrument and providing unique criteria for flare detection independent of the observer.     

The new site testing survey in the Canary Islands' Observatories

The future establishment of large telescopes at the Observatorio del Roque de los Muchachos (ORM) has raised the necessity of designing a site-testing campaign, aimed specifically at selecting their emplacements, as well as characterizing correctly the local seeing behaviour and the fluctuations of the turbulent field in the area covered by the observatory.This paper describes the site evaluation programme to be carried out at the ORM during the next four years. The data obtained in this program will improve earlier tests in the critical areas of sub-are sec seeing, the size of the isoplanatic patch, the efecto Caldera and suitability for infrared astronomy, among others.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

New Activity of Chiron: Results from 5 Years of Photometric Monitoring

The results of photometric observations of Centaur object Chiron carried out at the Observatório do Pico dos Dias (OPD, Brazil), the Estación Astrof?&#x0301;sica de Bosque Alegre (EABA, Argentina), and Complejo Astronómico El Leoncito (CASLEO, Argentina) from 1997 to 2001 are presented here. The analysis of the photometric data shows that the brightness of Chiron reached a minimum value in 1999 and began increasing again in 2000. The absolute magnitude, H_V, varied from 7.26 in June 1999 to 5.78 in April 2001. The data tend to indicate that Chiron is starting a new outburst of activity which is compatible with a sporadic cometary behavior not related to heliocentric distance.     

Observations of the supernova SN1987L with the new Faint Object Spectrograph on the 4.2 m William Herschel Telescope

We present the spectrum of the supernova SN1987L in NGC 2336 over the wavelength range 4000–9700 Å as recorded in one 500 s exposure on 20–21 October, 1987. This spectrum was taken using the new Faint Object Spectrograph on the 4.2 m William Herschel Telescope (WHT) at the Observatorio del Roque de los Muchachos.We conclude that SN1987L was a type Ia supernova, and approximately 100 days post maximum at the time of the observation.     

Observations of SN1988e: A mature supernova

We present the spectrum of the supernova SN1988e over the wavelength range 4750–9000 Å as recorded on 11 February, 1988. The spectrum was taken in one 2000 s exposure using the Faint Object Spectrograph on the 4.2 m William Herschel Telescope (WHT) at the Observatorio del Roque de los Muchachos.We conclude that SN1988e was a type I supernova, and that at the time of observation it had faded 7.5 mag from its predicted magnitude at maximum light. Spectra taken at such late stages in the light curve are comparatively rare, and are made possible only with the application of modern instrumentation.     

Observations of the supernova 1985F with a new spectrograph

We present the spectrum of the supernova 1985F over the wavelength range 4600 to 10000 Å as recorded in one 200 s exposure on 16 May, 1985, when its age was estimated to bet240 days. This wideband measurement with a resolution of 20 Å was made with the new Faint Object Spectrograph on the Isaac Newton Telescope (INT) at the Observatorio del Roque de los Muchachos. Broad line features were observed for the ionsOi,Oii, andOiii, Caii, and Nai although broad H was noteably absent. This suggests type I rather than type II properties but Filippenko and Sargent (1985c) have concluded this object to be of neither type and of a new peculiar class. We have observed the Caii infra-red triplet at 8600 Å which has not been previously reported in the spectrum of SN1985F and alsoCi] at 9800 Å.     

What can we learn from arcs in clusters of galaxies?

Photon-counting techniques have been applied to a study of the movement of the image of an unresolved star at the 50 cm telescope of the Royal Academy of Sciences, at the Roque de los Muchachos Observatory. The temporal autocorrelation function of such movement has been computed, the results are discussed in terms of atmospheric turbulence and in relation to high-resolution imaging.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

The Galileo Italian National Telescope and its Instrumentation

The main features of the 3.5m Telescopio Nazionale GALILEO (TNG) have been derived from those of the ESO NTT, although with modifications in several areas, as described e.g. in Barbieri et al., 1994. The site of the TNG is the Observatorio del Roque de los Muchachos, in the Canary Island of La Palma. Construction activities, started in 1993, are nearing completion. The telescope structure, after testing in the Ansaldo factory near Milano, has been disassembled and is gradually being transported and installed on site, in parallel with the rotating dome. The three main mirrors, figured by ZEISS, will be transported in spring '96 to the WHT plant at the Roque for aluminisation before installation on the telescope.Three major subsystems still undergo intensive activity in Italy, namely testing of the M2 and M3 units, testing of the operational version of the control hardware and software, and construction of the two Rotator Adapters (R/A) for the Nasmyth foci.First light instruments are also being built. Nasmyth Arm A is reserved for the imaging section, composed by a visual camera, a near-IR camera, plus a common adaptive optics module. On arm B, a faint object spectrograph with long slit, atmospheric dispersion corrector, multiobject and imaging capabilities, will be mounted. A fixed high resolution spectrograph with optical derotation is also being designed.Attention has already been given to the archive of the data.It is planned to have first light at the end of 1996, and to start regular scientific operations after an adequate period of debugging and commissioning.