Spanish Observatorio Del Roque De Research Articles

Spectral Rotational Characterization of the Didymos System prior to the DART Impact* *Based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundación Galileo Galilei of the Istituto Nazionale di Astrofisica (INAF) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias (Program AOT42-TAC8).

The smallest member of the Didymos binary near-Earth object system (Dimorphos) is the target of the DART/LICIACube mission, the first attempt to change the orbit of another celestial body via a kinetic impactor. It is important to characterize the unperturbed system prior to the DART impact. In this work we obtained, for the first time, spectral characterization of the system at several rotational phases from TNG+DOLORES in the visible range (0.34–0.81 μm). This is crucial in order to disentangle the primary and secondary bodies and highlight eventual dishomogeneities on their surfaces. We confirm that a subtle but persistent spectral variability appears, even when compared with data obtained from previous 2003 and 2019 apparitions. While the reason for such variability is still under investigation, our analysis hints that different compositions could play a role. Future observations during the brighter 2022 apparition in synergy with data obtained from LUKE on board LICIACube will definitely tackle this conundrum.

Physical properties of PHA 2014 JO25 from a worldwide observational campaign

J. Licandro (JL), M. Serra-Ricart (MSR), O. Vaduvescu (OV), M. Popescu (MP), and J. de Leon (JdL) acknowledge support from the AYA2015-67772-R project (MINECO, Spain). JdL also acknowledges support from from MINECO under the 2015 Severo Ochoa Program SEV-2015-0548. The Isaac Newton Telescope and its service mode are operated on the island of La Palma by the Isaac Newton Group of Telescopes in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. The work of MP was also been supported by a grant of the Romanian National Authority for Scientific Research - UEFISCDI, project number PN-II-RU-TE-2014-4-2199. The research leading to these results has received funding from the European Union's Horizon 2020 Research and Innovation Programme, under Grant Agreement No. 687378. We thank E. Molinari for allocation of Director's Discretionary Time at the Telescopio Nazionale Galileo. The work by P. Pravec was supported by the Grant Agency of the Czech Republic, Grant 17-00774S. Observations at CS3 and continued support of the asteroid light-curve data base (LCDB; Warner et al. 2009) are supported by NASA grant 80NSSC18K0851. This paper is partially based on data taken at the 0.77 m La Hita telescope, which is jointly operated by the Instituto de Astrofisica de Andalucia-CSIC and Astrohita. Blue Mountains Observatory is supported by the 2015 Shoemaker NEO grant.

HAT-P-55b: A Hot Jupiter Transiting a Sun-Like Star11Based on observations obtained with the Hungarian-made Automated Telescope Network. Based in part on radial velocities obtained with the SOPHIE spectrograph mounted on the 1.93-m telescope at Observatoire de Haute-Provence, France. Based in part on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland,

We report the discovery of a new transiting extrasolar planet, HAT-P-55b. The planet orbits a V = 13.207 ± 0.039 sun-like star with a mass of 1.013 ± 0.037 M⊙, a radius of 1.011 ± 0.036 R⊙, and a metallicity of -0.03 ± 0.08. The planet itself is a typical hot Jupiter with a period of 3.5852467 ± 0.0000064 days, a mass of 0.582 ± 0.056 MJ and a radius of 1.182 ± 0.055 RJ. This discovery adds to the increasing sample of transiting planets with measured bulk densities, which is needed to put constraints on models of planetary structure and formation theories.

KIC 10526294: a slowly rotating B star with rotationally split, quasi-equally spaced gravity modes(Corrigendum)

? Based on observations made with the William Herschel Telescope operated by the Isaac Newton Group on the island of La Palma at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. ?? Appendices are available in electronic form at http://www.aanda.org ??? Postdoctoral Fellow of the Belgian Science Policy Office (BELSPO), Belgium. ???? Postdoctoral Fellow of the Fund for Scientific Research (FWO), Flanders, Belgium. † Postdoctoral Fellow of the Fund for Scientific Research (FWO), Flanders, Belgium.

Deep optical imaging and spectroscopy of the lens system SDSS J1339+1310

Acknowledgements. We wish to thank the anonymous referee for her/his con-structive comments, which have significantly improved the original manuscript. Based on observations made with the Gran Telescopio Canarias (GTC), installed at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, in the island of La Palma. This article is also based on observations made with the Nordic Optical Telescope (NOT) and the Liverpool Telescope (LT), operated on the island of La Palma by the Nordic Optical Telescope Scientific Association and the Liverpool John Moores University(with financial support from the UK Science and Technology Facilities Council),respectively, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. This research has been supported by the Spanish Department of Science and Innovation grant AYA2010-21741-C03-03 (Gravitational LENses and DArk MAtter−GLENDAMA project), and the University of Cantabria.

Flux-Calibrated Emission-Line Imaging of Extended Sources Using GTC/OSIRIS Tunable Filters11Based on observations made with the Gran Telescopio Canarias (GTC), installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, in the island of La Palma.

ABSTRACTWe investigate the utility of the tunable filters (TFs) for obtaining flux-calibrated emission-line maps of extended objects such as galactic nebulae and nearby galaxies using the Optical System for Imaging and low Resolution Integrated Spectroscopy (OSIRIS) at the 10.4-m Gran Telescopio Canarias (GTC). Despite the relatively large field of view (FoV) of OSIRIS (8′ × 8′), the change in wavelength across the field (∼80 Å) and the long tail of the TF spectral response function are hindrances for obtaining accurate flux-calibrated emission-line maps of extended sources. The purpose of this article is to demonstrate that emission-line maps useful for diagnostics of nebulae can be generated over the entire FoV of OSIRIS if we make use of theoretically well-understood characteristics of TFs. We have successfully generated the flux-calibrated images of the nearby large late-type spiral galaxy M101 in the emission lines of Hα, [N II]λ6583, [S II]λ6716 and [S II]λ6731. We find that the present uncertainty in setting the central wavelength of TFs (∼1 Å) is the biggest source of error in the emission-line fluxes. By comparing the Hα fluxes of H II regions in our images with the fluxes derived from Hα images obtained using narrow-band filters, we estimate an error of ∼11% in our fluxes. The flux-calibration of the images was carried out by fitting the Sloan Digital Sky Survey (SDSS) griz magnitudes of in-frame stars with the stellar spectra from the SDSS spectral database. This method resulted in an accuracy of 3% in flux-calibration of any narrow-band image, which is as good as, if not better than, what has been feasible using the observations of spectrophotometric standard stars. Thus time-consuming calibration images need not be taken. A user-friendly script under the IRAF environment was developed and is available on request.

Wavelength Calibration for OSIRIS/GTC11This work is based on observations made with the GTC operated on the island of La Palma by Grantecan in the Spanish Observatorio del Roque de los Muchachos. Tunable Filters

ABSTRACTOSIRIS (Optical System for Imaging and low Resolution Integrated Spectroscopy) is the first light instrument of the Gran Telescopio Canarias (GTC). It provides a flexible and competitive tunable filter (TF). Since it is based on a Fabry-Perot interferometer working in a collimated beam, the TF transmission wavelength depends on the position of the target with respect to the optical axis. This effect is nonnegligible and must be accounted for in the data reduction. Our article establishes a wavelength calibration for OSIRIS TF with the accuracy required for spectrophotometric measurements using the full field of view (FOV) of the instrument. The variation of the transmission wavelength λ(R) across the FOV is well described by , where λ(0) is the central wavelength, R represents the physical distance from the optical axis, and f2 = 185.70 ± 0.17 mm is the effective focal length of the camera lens. This new empirical calibration yields an accuracy better than 1 Å across the entire OSIRIS FOV (∼8′ × 8′), provided that the position of the optical axis is known within 45 μm (≡1.5 binned pixels). We suggest a calibration protocol to grant such precision over long periods, upon realignment of OSIRIS optics, and in different wavelength ranges. This calibration differs from the calibration in the OSIRIS manual, which nonetheless provides an accuracy ≲1 Å for R ≲ 2′.

Oscillator strength measurements of atomic absorption lines from stellar spectra1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.2Based in part on observations made with the Mercator Telescope, operated on the island of La Palma by the Flemish Community, at the Spanish Observatorio del Roque de

Herein we develop a new method to determine oscillator strength values of atomic absorption lines with state-of-the-art detailed spectral synthesis calculations of the optical spectrum of the Sun and of standard spectral reference stars. We update the log(gf) values of 911 neutral lines observed in the KPNO–FTS flux spectrum of the Sun and high-resolution echelle spectra (R = 80 000) of Procyon (F5 IV–V) and [Formula: see text] Eri (K2 V) observed with large signal-to-noise (S/N) ratios of ∼2000 using the new Mercator–Hermes spectrograph at La Palma Observatory (Spain). We find for 483 Fe i, 85 Ni i, and 51 Si i absorption lines in the sample a systematic overestimation of the literature log(gf) values with central line depths below 15%. We employ a curve-of-growth analysis technique to test the accuracy of the new oscillator strength values and compare calculated equivalent line widths to the Moore, Minnaert, and Houtgast atlas of the Sun. The online SpectroWeb database at spectra.freeshell.org interactively displays the observed and synthetic spectra and provides the new log(gf) values together with important atomic line data. The graphical database is under development for stellar reference spectra of every spectral sub-class observed with large spectral resolution and S/N ratios.

LOW-RESOLUTION SPECTROSCOPY OF GAMMA-RAY BURST OPTICAL AFTERGLOWS: BIASES IN THE SWIFT SAMPLE AND CHARACTERIZATION OF THE ABSORBERS

We present a sample of 77 optical afterglows (OAs) of Swift detected gamma-ray bursts (GRBs) for which spectroscopic follow-up observations have been secured. Our first objective is to measure the redshifts of the bursts. For the majority (90%) of the afterglows, the redshifts have been determined from the spectra. We provide line lists and equivalent widths (EWs) for all detected lines redward of Lyα covered by the spectra. In addition to the GRB absorption systems, these lists include line strengths for a total of 33 intervening absorption systems. We discuss to what extent the current sample of Swift bursts with OA spectroscopy is a biased subsample of all Swift detected GRBs. For that purpose we define an X-ray-selected statistical sample of Swift bursts with optimal conditions for ground-based follow-up from the period 2005 March to 2008 September; 146 bursts fulfill our sample criteria. We derive the redshift distribution for the statistical (X-ray selected) sample and conclude that less than 18% of Swift bursts can be at z > 7. We compare the high-energy properties (e.g., γ-ray (15-350 keV) fluence and duration, X-ray flux, and excess absorption) for three subsamples of bursts in the statistical sample: (1) bursts with redshifts measured from OA spectroscopy; (2) bursts with detected optical and/or near-IR afterglow, but no afterglow-based redshift; and (3) bursts with no detection of the OA. The bursts in group (1) have slightly higher γ-ray fluences and higher X-ray fluxes and significantly less excess X-ray absorption than bursts in the other two groups. In addition, the fractions of dark bursts, defined as bursts with an optical to X-ray slope βOX 39% in group (3). For the full sample, the dark burst fraction is constrained to be in the range 25%-42%. From this we conclude that the sample of GRBs with OA spectroscopy is not representative for all Swift bursts, most likely due to a bias against the most dusty sight lines. This should be taken into account when determining, e.g., the redshift or metallicity distribution of GRBs and when using GRBs as a probe of star formation. Finally, we characterize GRB absorption systems as a class and compare them to QSO absorption systems, in particular the damped Lyα absorbers (DLAs). On average GRB absorbers are characterized by significantly stronger EWs for H I as well as for both low and high ionization metal lines than what is seen in intervening QSO absorbers. However, the distribution of line strengths is very broad and several GRB absorbers have lines with EWs well within the range spanned by QSO-DLAs. Based on the 33 z > 2 bursts in the sample, we place a 95% confidence upper limit of 7.5% on the mean escape fraction of ionizing photons from star-forming galaxies. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, under programs 275.D-5022 (PI: Chincarini), 075.D-0270 (PI: Fynbo), 077.D-0661 (PI: Vreeswijk), 077.D-0805 (PI: Tagliaferri), 177.A-0591 (PI: Hjorth), 078.D-0416 (PI: Vreeswijk), 079.D-0429 (PI: Vreeswijk), 080.D-0526 (PI: Vreeswijk), 081.A-0135 (PI: Greiner), 281.D-5002 (PI: Della Valle), and 081.A-0856 (PI: Vreeswijk). Also based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. Some of the data obtained herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck foundation.

Homogeneous Photometry. III. A Star Catalog for the Open Cluster NGC 67911,1Based in part on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. 22This paper uses data provided by J.

ABSTRACTWe present broadband BVI photometry for the open cluster NGC 6791, based upon analysis of 1764 individual CCD images. We discuss in detail the transformation of the instrumental magnitudes to the standard photometric system of Landolt and then discuss methods for selecting a subset of cluster stars whose photometric indices are most likely to be of high reliability. Color‐magnitude and color‐color diagrams for the cluster are presented and discussed. A detailed comparison of this photometry with the results of previous observational studies is presented. We make preliminary comparisons with theoretical isochrones provided by D. A. VandenBerg and conclude that an excellent match can be achieved if the metal abundance and age of the cluster are both near the upper end of the range of recent estimates ([Fe/H] ≈ +0.3, age ≈ 12 Gyr) and the reddening and true distance modulus are both near the low end of the range of recent estimates [E(B−V) ≈ 0.09 mag and (m−M)0 ≈ 12.79 mag] if the isochrone predictions are reliable. A companion paper will discuss candidate variable stars and stars possibly showing planetary transits. Data tables listing measured magnitudes and standard errors, image‐quality indices, a variability index, and equinox J2000.0 equatorial coordinates for 14,342 stars to V∼24 have been made available to the public through the services of the Canadian Astronomy Data Centre. Equatorial coordinates only have been provided for a further 1916 stars, the photometry for which we were unable to calibrate because of lack of color information.

Double star CCD astrometry and photometry

About 3000 CCD measurements of double stars have been made in one or both filters V and R on the 1m Jacobus Kapteyn Telescope at La Palma. ∗ ∗ The Jacobus Kapteyn Telescope is 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. The stars form part of the INput CAtalogue (INCA) of the astrometric satellite HIPPARCOS, and require both astrometry and photometry in order to facilitate reduction of the HIPPARCOS measurements. The primary components of the binaries have visual magnitudes between 8 m and 12 m, and the apparent separations between components range from 0″.5 to 30″. The difference in the separation obtained with the two filters is discussed and illustrated for 2100 systems: the dependence upon separation and magnitude difference between components is clearly and quantitatively shown.