UBVRI-CCD photometry of Cepheus OB3 association

Johnson CCD photometry was performed in the two subgroups of the association Cepheus OB3, for selected fields each containing at least one star with previous UBV photoelectric photometry. Photometry for about 1000 stars down to visual magnitude 21 is provided, although the completeness tests show that the sample is complete down to V=19mag. Individual errors were assigned to the magnitude and colours for each star. Colour-colour and colour-magnitude diagrams are shown. Astrometric positions of the stars are also given. Description of the reduction procedure is fully detailed.

Secondary UBVRI-CCD standard stars in the neighbourhood of Landolt standard stars

A list of 681 UBVRI secondary standard stars for CCD photometry is presented. Visual magnitude ranges from 9.7 to 19.4, and the B-V colour index varies from 1.15 to 1.97. The stars are grouped into 11 different fields, each of them is generally observable in a single CCD frame. The stars are located near Landolt UBVRI equatorial standards, accessible to telescopes in both hemispheres, and mainly within the 5 - 8 hours range of right ascension. Photometry, equatorial coordinates and finding charts are provided.

Analysis of total visual and CCD V-broadband observations of Comet C/1995 O1 (Hale-Bopp): 1995-2001

We developed a general method for determination of water production rates from groundbased visual observations and applied it to Comet Hale-Bopp. Our main objective is to extend the method to include total visual magnitude observations obtained with CCD detector and V filter in the analysis of total visual magnitudes. We compare the CCD V-broadband careful observations of Liller [Liller, W. Pre-perihelion CCD photometry of Comet 1995 01 (Hale-Bopp). Planet. Space Sci. 45, 1505-1513, 1997; Liller, W. CCD photometry of Comet C/1995 O1 (Hale-Bopp): 1995-2000. Int. Comet Quart. 23(3), 93-97, 2001] with the total visual magnitude observations from experienced international observers found in the International Comet Quarterly (ICQ) archive. A data set of similar to 400 CCD observations covering about the same 6 years time span of the similar to 12,000 ICQ selected total visual magnitude observations were used in the analysis. A least-square method applied to the water production rates, yields power laws as a function of the heliocentric distances for the pre- and post-perihelion phases. The average dimension of the nucleus as well as its effective active area is determined and compared with values published in the literature. (C) 2009 COSPAR. Published by Elsevier Ltd. All rights reserved.

The old metal-poor open cluster ESO 92-SC05: accreted from a dwarf galaxy ?

The study of old open clusters outside the solar circle can bring constraints on formation scenarios of the outer disc. In particular, accretion of dwarf galaxies has been proposed as a likely mechanism in the area. We use BVI photometry for determining fundamental parameters of the faint open cluster ESO 92-SC05. Colour-magnitude diagrams are compared with Padova isochrones, in order to derive age, reddening and distance. We derive a reddening E(B - V) = 0.17, and an old age of similar to 6.0 Gyr. It is one of the rare open clusters known to be older than 5 Gyr. A metallicity of Z similar to 0.004 or [M/H] similar to -0.7 is found. The rather low metallicity suggests that this cluster might be the result of an accretion episode of a dwarf galaxy.

Observations de pulsateurs compacts à l'aide de la caméra Mont4K CCD

Les pulsateurs compacts sont des étoiles présentant des variations intrinsèques de luminosité dont les gravités de surface sont supérieures à 100,000 cm/s² On retrouve parmi ces objets deux familles des sous-naines chaudes de type B (sdB) pulsantes et quatre familles distinctes de naines blanches pulsantes. Dans le but d'observer les pulsations de tels objets pour ensuite analyser leur propriétés grâce à l'astéroséismologie, l'Université de Montréal, en collaboration avec le Imaging Technology Laboratory (ITL - University of Arizona), a développé la caméra Mont4K (Montreal4K) CCD qui est, depuis le printemps 2007, le principal détecteur employé au télescope Kuiper de 1.55 m du Mt Bigelow (Steward Observatory, University of Arizona). à l'aide de ce montage, des observations ont été menées pour quelques-uns de ces pulsateurs compacts. La première cible fut HS 0702+6043, un pulsateur hybride. Une importante mission pour cet objet, réalisée du 1er novembre 2007 au 14 mars 2008, a permis d'identifier 28 modes de pulsations pour cet objet en plus de mettre en évidence pour certains de ces modes d'importantes variations d'amplitude. Deux autres cibles furent les naines blanches pulsantes au carbone de type « Hot DQ » SDSS J220029.08-074121.5 et SDSS J234843.30-094245.3. Il fut possible de montrer de façon indirecte la présence d'un fort champ magnétique à la surface de J220029.08-074121.5 grâce à la présence de la première harmonique du mode principal. En outre, pour ces deux cibles, on a pu conclure que celles-ci font bel et bien partie de la classe des naines blanches pulsantes au carbone.

CHEOPS: a space telescope for ultra-high precision photometry of exoplanet transits

The CHaracterising ExOPlanet Satellite (CHEOPS) is a joint ESA-Switzerland space mission (expected to launch in 2017) dedicated to search for exoplanet transits by means of ultra-high precision photometry. CHEOPS will provide accurate radii for planets down to Earth size. Targets will mainly come from radial velocity surveys. The CHEOPS instrument is an optical space telescope of 30 cm clear aperture with a single focal plane CCD detector. The tube assembly is passively cooled and thermally controlled to support high precision, low noise photometry. The telescope feeds a re-imaging optic, which supports the straylight suppression concept to achieve the required Signal to Noise. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

uvby-beta photometry of solar twins The solar colors, model atmospheres, and the T(eff) and metallicity scales

Aims. Solar colors have been determined on the uvby-beta photometric system to test absolute solar fluxes, to examine colors predicted by model atmospheres as a function of stellar parameters (T(eff), log g, [Fe/H]), and to probe zero-points of T(eff) and metallicity scales. Methods. New uvby-beta photometry is presented for 73 solar-twin candidates. Most stars of our sample have also been observed spectroscopically to obtain accurate stellar parameters. Using the stars that most closely resemble the Sun, and complementing our data with photometry available in the literature, the solar colors on the uvby-beta system have been inferred. Our solar colors are compared with synthetic solar colors computed from absolute solar spectra and from the latest Kurucz (ATLAS9) and MARCS model atmospheres. The zero-points of different T(eff) and metallicity scales are verified and corrections are proposed. Results. Our solar colors are (b - y)(circle dot) = 0.4105 +/- 0.0015, m(1,circle dot) = 0.2122 +/- 0.0018, c(1,circle dot) = 0.3319 +/- 0.0054, and beta(circle dot) = 2.5915 +/- 0.0024. The (b - y)(circle dot) and m(1,circle dot) colors obtained from absolute spectrophotometry of the Sun agree within 3-sigma with the solar colors derived here when the photometric zero-points are determined from either the STIS HST observations of Vega or an ATLAS9 Vega model, but the c(1,circle dot) and beta(circle dot) synthetic colors inferred from absolute solar spectra agree with our solar colors only when the zero-points based on the ATLAS9 model are adopted. The Kurucz solar model provides a better fit to our observations than the MARCS model. For photometric values computed from the Kurucz models, (b - y)(circle dot) and m(1,circle dot) are in excellent agreement with our solar colors independently of the adopted zero-points, but for c(1,circle dot) and beta circle dot agreement is found only when adopting the ATLAS9 zero-points. The c(1,circle dot) color computed from both the Kurucz and MARCS models is the most discrepant, probably revealing problems either with the models or observations in the u band. The T(eff) calibration of Alonso and collaborators has the poorest performance (similar to 140 K off), while the relation of Casagrande and collaborators is the most accurate (within 10 K). We confirm that the Ramirez & Melendez uvby metallicity calibration, recommended by Arnadottir and collaborators to obtain [Fe/H] in F, G, and K dwarfs, needs a small (similar to 10%) zero-point correction to place the stars and the Sun on the same metallicity scale. Finally, we confirm that the c(1) index in solar analogs has a strong metallicity sensitivity.

The Las Campanas/AAT rich cluster survey - I. Precision and reliability of the photometric catalogue

The Las Campanas Observatory and Anglo-Australian Telescope Rich Cluster Survey (LARCS) is a panoramic imaging and spectroscopic survey of an X-ray luminosity-selected sample of 21 clusters of galaxies at 0.07 < z < 0.16. Charge-coupled device (CCD) imaging was obtained in B and R of typically 2 degrees wide regions centred on the 21 clusters, and the galaxy sample selected from the imaging is being used for an on-going spectroscopic survey of the clusters with the 2dF spectrograph on the Anglo-Australian Telescope. This paper presents the reduction of the imaging data and the photometric analysis used in the survey. Based on an overlapping area of 12.3 deg(2) we compare the CCD-based LARCS catalogue with the photographic-based galaxy catalogue used for the input to the 2dF Galaxy Redshift Survey (2dFGRS) from the APM, to the completeness of the GRS/APM catalogue, b(J) = 19.45. This comparison confirms the reliability of the photometry across our mosaics and between the clusters in our survey. This comparison also provides useful information concerning the properties of the GRS/APM. The stellar contamination in the GRS/APM galaxy catalogue is confirmed as around 5-10 per cent, as originally estimated. However, using the superior sensitivity and spatial resolution in the LARCS survey evidence is found for four distinct populations of galaxies that are systematically omitted from the GRS/APM catalogue. The characteristics of the 'missing' galaxy populations are described, reasons for their absence examined and the impact they will have on the conclusions drawn from the 2dF Galaxy Redshift Survey are discussed.

Digital image analysis to standardize a photometric method in colorimetric quantification

Techniques applying digital images increasingly have been used in biology, medicine, physics, and other research areas. The image coordinates can represent light intensities values to be detected by a CCD. Based on this concept, a photometric system composed of a LED source and a digital camera as a detector was used for optical density measurements. Standards for permanganate, glucose, and protein solutions were detemined by colorimetric methods using our device. Samples of protein of Pasteurella mutocida bacteria membrane and, also, fractions of rabbit kidney membrane, rich in Na, K-ATPase, with unknown concentrations were dosed through the Hartree method using our photometric system.

Dynamics of serotonergic neurons revealed by fiber photometry

This work was developed in the context of the MIT Portugal Program, area of Bioengineering Systems, in collaboration with the Champalimaud Research Programme, Champalimaud Center for the Unknown, Lisbon, Portugal. The project entitled Dynamics of serotonergic neurons revealed by fiber photometry was carried out at Instituto Gulbenkian de Ciência, Oeiras, Portugal and at the Champalimaud Research Programme, Champalimaud Center for the Unknown, Lisbon, Portugal

RELATÓRIO DE TRANVERSALIDADE E SINERGIA ENTRE AS TRÊS CONVENÇÕES DE RIO (CCD, CBD, CCC)

- Este relatório refere a avaliação transversal e estabelecimento de sinergias entre as três Convenções do Rio (CCD, CD, CCC), no âmbito da Autoavaliação das Capacidades Nacionais para a Gestão Ambiental Global. Mostrando-se necessário ultrapassar as políticas e traduzir essas políticas em acções práticas e concretas, principalmente em acções de capacitação em gestão ambiental foi elaborado e apresentado para financiamento o projecto NCSA-GEM para reforçar as capacidades nacionais em termos individuais, institucionais e sistémico, nos domínios prioritários das Convenções Internacionais de Rio e, consequentemente reforçar a implementação do PANA II enquanto instrumento estratégico da politica nacional para a gestão do ambiente. - Os desafios do Ambiente Mundial mobilizam, desde há varias décadas, a comunidade internacional. A iniciativa condutora da estratégia de luta da comunidade internacional apareceu sob forma de Desenvolvimento Durável, lançado em Estocolmo em 1972, e confirmado na Conferência de Rio em 1992, através do consenso à volta dos princípios, recomendações e acções da Agenda 21 e, sobretudo das Convenções Internacionais, como nova abordagem da problemática do ambiente mundial. Para confirmar a sua participação na luta contra as ameaças ambientais planetários, Cabo Verde ratificou as principais convenções internacionais e comprometeu se a implementa-las através de estratégias e planos de acção. A ligação entre a Gestão Ambiental Global e o Desenvolvimento Durável é capital para um país como Cabo Verde. Os “cenários” de desenvolvimento humano e económico, tendo em conta a vulnerabilidade ambiental e no contexto de um pequeno estado insular em desenvolvimento (SIDS), devem ser bem avaliados e implementados com uma visão estratégica integrada, sinérgica e de longo prazo. - Este trabalho teve como principal objectivo identificar as forças, constrangimentos e as necessidades prioritárias em matéria de reforço das capacidades do sistema nacional de gestão ambiental aos 3 níveis, assim como as oportunidades que potenciam as ligações e sinergias entre as três Convenções do Rio. Foram também identificadas questões de reforço das capacidades que são comuns e necessárias para a Gestão do Ambiente Mundial, visando integrar os acordos ambientais multilaterais (MEA, Convenções do Rio) nos documentos de planificação estratégica e orçamental (ODM, DSCRP, SMDD, PANA, PND). - Este documento é o resultado das actividades da FASE IV do processo de implementação do NCSA em Cabo Verde. Este processo envolve 5 fases chave: o lançamento do processo (Fase I), o diagnostico da situação ambiental, (Fase II), a elaboração dos perfis temáticos (Fase III), a análise intersectorial (Fase IV), e a elaboração da Estratégia Nacional e Plano de Acção – NCSA (Fase V). - De acordo com a metodologia e orientações do projecto NCSA este documento é o resultado da 2ª actividade, de análise dos pontos de convergência e ligações sinérgicas existentes entre as 3 convenções de Rio. Tendo como ponto de partida a elaboração dos perfis temáticos CBD, CCC e CCD. A abordagem utilizada foi a análise de toda a documentação existente sobre as três Convenções (CCD, CBD; CCC) e Gestão Ambiental, realização de entrevistas e a recolha de informações através da realização de jornadas e ateliers a nível de alguns municípios – chaves. Os consultores animaram algumas sessões de trabalho, três (3) jornadas, mesas redondas regionais no Tarrafal, em S.Domingos (Santiago) e no Mindelo (S. Vicente) e dois ateliers nacionais Mindelo - S. Vicente (8 e 9 de Fevereiro 2007) e Praia – Santiago (01 de Março 2007) para aprofundar o entendimento das questões ligadas aos perfis temáticos e avaliar as necessidades prioritárias de reforço das capacidades nacionais no quadro das três Convenções (CCD, CBD,CCC) e da Gestão Ambiental. As sessões de trabalho foram realizadas com responsáveis de instituições públicas, privadas e ONGs, estruturas directamente envolvidas nas questões do ambiente. Os ateliers incluíram diferentes actores, parceiros técnicos e financeiros tais como representantes da administração central, do poder local, do sector privado e da sociedade civil. - Nesta fase IV, identificou-se um conjunto de necessidades de reforço das capacidades a nível de cada Convenção específica. De seguida, a análise focalizou, de acordo com o processo NCSA, as questões de reforço das capacidades intersectoriais comuns as três Convenções do Rio. Identificou-se ainda actividades habilitantes de integração entre os sectores de intervenção das 3C e as sinergias para a implementação das Convenções. Os resultados desta fase são a base para o arranque da fase V, que visa a elaboração da Estratégia Nacional e Plano de Acção NCSA. As possíveis linhas de orientação são: • Gestão (integrada) dos RN • Reforço das Capacidades para a GI - RN • Investigação para a GI-RN - Concluindo este trabalho, no âmbito da fase IV, recomenda-se para: • Proceder a uma revisão dos documentos de politica e estratégia nacional do desenvolvimento e do ambiente, para sua integração numa ESTRATEGIA NACIONAL DE DESENVOLVIMENTO SUSTENTAVEL; • Implementar uma Estratégia de Mobilização de fundos, para garantir em primeiro lugar a durabilidade do processo NCSA em Cabo Verde, e em segundo lugar a sustentabilidade das instituições nacionais para a implementação da política de Gestão Ambiental; • Implementar uma Estratégia de Comunicação NCSA, para apoiar o desenvolvimento de uma estratégia de IEC em gestão ambiental; Reforçar o actual SIA para sua transformação num verdadeiro Sistema Nacional de Gestão Ambiental, enquanto instrumento estratégico de ordenamento do território, apoio à decisão, planificação do desenvolvimento económico visando a conservação e utilização durável dos recursos naturais.

UBVRI photoelectric photometry of nearby stars. II.

A second set of UBVRI photometry results for nearby stars of Gliese's (1969) catalog and its supplements, including in this case some multiple systems, are presented. Most of the observations were carried out between July 1984 and December 1985 at Calar Alto with the 1.23-m Centro Astronomico Hispano-Aleman telescope and the 1.52-m Observatorio Astronomico Nacional telescope. The number of observations of program and standard stars for the six runs and the final results for 60 stars are presented.

uvbyHbeta photometry of main sequence A type stars.

We present Stroemgren uvby and Hbeta_ photometry for a set of 575 northern main sequence A type stars, most of them belonging to the Hipparcos Input Catalogue, with V from 5mag to 10mag and with known radial velocities. These observations enlarge the catalogue we began to compile some years ago to more than 1500 stars. Our catalogue includes kinematic and astrophysical data for each star. Our future goal is to perform an accurate analysis of the kinematical behaviour of these stars in the solar neighbourhood.

An analysis of the currently available calibrations inStromgren photometry by using open clusters

In recent years, several authors have revised the calibrations used to compute physical parameters (tex2html_wrap_inline498, tex2html_wrap_inline500, log g, [Fe/H]) from intrinsic colours in the tex2html_wrap_inline504 photometric system. For reddened stars, these intrinsic colours can be computed through the standard relations among colour indices for each of the regions defined by Strömgren (1966) on the HR diagram. We present a discussion of the coherence of these calibrations for main-sequence stars. Stars from open clusters are used to carry out this analysis. Assuming that individual reddening values and distances should be similar for all the members of a given open cluster, systematic differences among the calibrations used in each of the photometric regions might arise when comparing mean reddening values and distances for the members of each region. To classify the stars into Strömgren's regions we extended the algorithm presented by Figueras et al. (1991) to a wider range of spectral types and luminosity classes. The observational ZAMS are compared with the theoretical ZAMS from stellar evolutionary models, in the range tex2html_wrap_inline506 K. The discrepancies are also discussed.