Garcia-Varela, A., Pietrzynski, G., Gieren, W., Udalski, A., Soszynski, I., Walker, A., ...
We report on the discovery of a Cepheid population in the Sculptor Group spiral galaxy NGC 247 for the first time. On the basis of wide-field images collected in photometric surveys in V and I bands...
Urbaneja, M. A., Bresolin, F., Przybilla, N., Gieren, W., Pietrzynski, G.
The quantitative analysis of low resolution spectra of A and B supergiants is used to determine a distance modulus of 24.99 +/- 0.10 mag (995 +/- 46 Kpc) to the Local Group galaxy WLM. The analysis...
The Araucaria Project: VLT-spectroscopy of blue massive stars in NGC 55 (2008)
Castro, N., Herrero, A., Garcia, M., Trundle, C., Bresolin, F., Gieren, W., ...
This is the first paper of a series devoted to studying the population of blue massive stars in NGC 55, a galaxy of the Sculptor group at a distance of about 2 Mpc. We have obtained optical...
Gieren, W., Pietrzynski, G., Szewczyk, O., Bresolin, F., Urbaneja, M. A., ...
We have obtained deep images in the near-infrared J and K filters for several fields in the Local Group galaxy WLM. We report intensity mean magnitudes for 31 Cepheids located in these fields which...
The eclipsing LMC star OGLE05155332--6925581: a clue for Double Periodic Variables (2008)
Mennickent, R. E., Kolaczkowski, Z., Michalska, G., Pietrzy'nski, G., Gallardo, R., Cidale, L., ...
We investigate the nature of OGLE05155332-6925581, one of the brightest members of the enigmatic group of Double Periodic Variables (DPVs) recently found in the Magellanic Clouds. The modeling of...
Pietrzynski, G., Gieren, W., Szewczyk, O., Walker, A., Rizzi, L., Bresolin, F., ...
We have obtained single-phase near-infrared magnitudes in the J and K bands for a sample of 78 RR Lyrae stars in the Sculptor dSph galaxy. Applying different theoretical and empirical calibrations of...
Urbaneja, M. A., Bresolin, F., Przybilla, N., Gieren, W., Pietrzynski, G.
A quantitative spectral analysis of 24 A supergiants in the Sculptor Group spiral galaxy NGC 300 at a distance of 1.9 Mpc is presented. A new method is introduced to analyze low resolution (~5 AE)...
Udalski, A., Pont, F., Naef, D., Melo, C., Bouchy, F., Santos, N. C., ...
We present results of the photometric campaign for planetary and low-luminosity object transits conducted by the OGLE survey in 2005 season (Campaign #5). About twenty most promising candidates...
A transiting planet among 23 new near-threshold candidates from the OGLE survey - OGLE-TR-182 (2007)
Pont, F., Tamuz, O., Udalski, A., Mazeh, T., Bouchy, F., Melo, C., ...
By re-processing the data of the second season of the OGLE survey for planetary transits and adding new mesurements on the same fields gathered in subsequent years with the OGLE telescope, we have...
A Catalogue of Be Stars in the Direction of the Galactic Bulge (2007)
Sabogal, B. E., Mennickent, R. E., Pietrzyński, G., García, J. A., Gieren, W., Kolaczkowski, Z., ...
Detailed studies of Be stars in environments with different metallicities like the Magellanic Clouds or the Galactic bulge are necessary to understand the formation and evolution mechanisms of the...
Fouque, P., Arriagada, P., Storm, J., Barnes, T. G., Nardetto, N., Merand, A., ...
The universality of the Cepheid Period-Luminosity relations has been under discussion since metallicity effects have been assumed to play a role in the value of the intercept and, more recently, of...
Gieren, W., Pietrzynski, G., Soszynski, I., Bresolin, F., Kudritzki, R. P., Storm, J., ...
We have obtained deep images in the near-infrared J and K filters of four fields in the Sculptor Group spiral galaxy NGC 55 with the ESO VLT and ISAAC camera. For 40 long-period Cepheid variables in...
Pietrzynski, G., Gieren, W., Udalski, A., Soszynski, I., Bresolin, F., Kudritzki, R. P., ...
We have conducted an extensive wide-field imaging survey for Cepheid variables in the Local Group irregular galaxy WLM. From data obtained on 101 nights, we have discovered 60 Cepheids which include...
A new Neptune-mass planet orbiting HD 219828 (2007)
Melo, C., Santos, N. C., Gieren, W., Pietrzynski, G., Ruiz, M. T., Sousa, S. G., ...
Two years ago a new benchmark for the planetary survey was set with the discoveries of three extrasolar planets with masses below 20$M_\oplus$. In particular, the serendipitous discovery of the...
A new Neptune-mass planet orbiting HD219828 (2007)
Melo, C., Santos, N. C., Gieren, W., Pietrzynski, G., Ruiz, M. T., Sousa, S. G., ...
Publicación ISI
Pont, F., Moutou, C., Gillon, M., Udalski, A., Bouchy, F., Fernandes, J. M., ...
Publicación ISI
A new Neptune-mass planet orbiting HD219828 (2007)
Melo, C., Santos, N. C., Gieren, W., Pietrzynski, G., Ruiz, M. T., Sousa, S. G., ...
Publicación ISI
Pont, F., Moutou, C., Gillon, M., Udalski, A., Bouchy, F., Fernandes, J. M., ...
Publicación ISI
Evans, C. J., Bresolin, F., Urbaneja, M. A., Pietrzynski, G., Gieren, W.
We have obtained multi-object spectroscopy of luminous blue supergiants in NGC 3109, a galaxy at the periphery of the Local Group at ~1.3 Mpc. We present a detailed catalog including finding charts,...
Pietrzynski, G., Gieren, W., Soszynski, I., Udalski, A., Bresolin, F., ...
We have detected, for the first time, Cepheid variables in the Sculptor Group SB(s)m galaxy NGC 55. From wide-field images obtained in the optical V and I bands during 77 nights in 2002-2003, we have...
Spectroscopy of blue and yellow long-period variables in the small magellanic cloud (2006)
R. E. Mennickent, W. Gieren, L. S. Cidale, G. Pietrzynski, B. Sabogal
Spectroscopy of blue and yellow long-period variables in the small magellanic cloud
The Araucaria Project. A Wide-Field Photometric Survey for Cepheid Variables in NGC 3109 (2006)
Pietrzynski, G., Gieren, W., Udalski, A., Soszynski, I., Bresolin, F., Kudritzki, R. P., ...
We have obtained mosaic images of NGC 3109 in the V and I bands on 74 nights, spanning approximately one year. From these data, we have conducted an extensive search for Cepheid variables over the...
Gieren, W., Pietrzynski, G., Nalewajko, K., Soszynski, I., Bresolin, F., Kudritzki, R. P., ...
We have measured near-infrared magnitudes in the J and K bands for 56 Cepheid variables in the Local Group galaxy NGC 6822 with well-determined periods and optical light curves in the V and I bands....
Soszynski, I., Gieren, W., Pietrzynski, G., Bresolin, F., Storm, J.
We present near-infrared J- and K-band photometry of 77 Cepheid variables in the Local Group galaxy NGC 3109. Combining our data with the previously published optical V- and I-band photometry of...
The Araucaria Project. Bright Variable Stars in NGC 6822 from a Wide-Field Imaging Survey (2006)
Mennickent, R. E., Gieren, W., Soszynski, I., Pietrzynski, G.
We have performed a search for variable stars in the dwarf irregular galaxy NGC 6822 using wide-field multi-epoch VI photometry down to a limiting magnitude $V$ $\sim$ 22. Apart from the Cepheid...
Pietrzynski, G., Gieren, W., Soszynski, I., Bresolin, F., Kudritzki, R. P., Dall'Ora, M., ...
We have measured accurate near-infrared magnitudes in the J and K bands of 39 Cepheid variables in IC 1613 with well-determined periods and optical VI light curves. Using the template light curve...
Spectroscopy of blue and yellow long-period variables in the small magellanic cloud (2006)
Cidale, L. S., Gieren, W., Mennickent, R. E., Pietrzynski, G., Sabogal, B.
Presentamos espectroscopía de 17 estrellas variables brillantes posibles miembros de la Nube Pequeña de Magallanes. Estas estrellas son variables OGLE cuya periodicidad fotométrica no ha sido...
Storm, J., Gieren, W., Fouque, P., Barnes III, T. G., Gomez, M.
We derive individual distances to six Cepheids in the young populous star cluster NGC1866 in the Large Magellanic Cloud employing the near-IR surface brightness technique. With six stars available at...
{Results from a long-term observational project called the Araucaria Project are presented. Based on Wide Field optical monitoring of 8 nearby galaxies, covering a large range of metallicities, more...
Gieren, W., Storm, J., Barnes III, T. G., Fouque, P., Pietrzynski, G., Kienzle, F.
We have applied the infrared surface brightness (ISB) technique to derive distances to 13 Cepheids in the LMC which span a period range from 3 to 42 days. From the absolute magnitudes of the...
Gieren, W., Pietrzynski, G., Walker, A., Bresolin, F., Minniti, D., Kudritzki, R. P., ...
In a previous paper, we reported on the discovery of more than a hundred new Cepheid variables in the Sculptor Group spiral NGC 300 from wide-field images taken in the B and V photometric bands at...
A Catalog of OB Associations in the spiral galaxy NGC 300 (2005)
Pietrzynski, G., Gieren, W., Fouque, P., Pont, F.
We present results of a search for OB associations in NGC 300. Using an automatic and objective method (PLC technique) 117 objects were found. Statistical tests indicate that our sample is...
Mean JHK Magnitudes of Fundamental-Mode Cepheids from Single-Epoch Observations (2005)
Soszynski, I., Gieren, W., Pietrzynski, G.
We present an empirical method for converting single-point near-infrared J, H, and K measurements of fundamental-mode Cepheids to mean magnitudes, using complete light curves in V or I bands. The...
Gieren, W., Pietrzynski, G., Soszynski, I., Bresolin, F., Kudritzki, R. P., Minniti, D., ...
We have obtained deep near-infrared images in J and K filters of three fields in the Sculptor galaxy NGC 300 with the ESO VLT and ISAAC camera. For 16 Cepheid variables in these fields, we have...
Gieren, W., Storm, J., Barnes III, T. G., Fouque, P., Pietrzynski, G., Kienzle, F.
We have applied the infrared surface brightness (ISB) technique to derive distances to 13 Cepheids in the LMC which span a period range from 3 to 42 days. From the absolute magnitudes of the...
Gieren, W., Storm, J., Barnes III, T. G., Fouque, P., Pietrzynski, G., Kienzle, F.
We have applied the infrared surface brightness (ISB) technique to derive distances to 13 Cepheids in the LMC which span a period range from 3 to 42 days. From the absolute magnitudes of the...
Gieren, W., Storm, J., Barnes III, T. G., Fouque, P., Pietrzynski, G., Kienzle, F.
We have applied the infrared surface brightness (ISB) technique to derive distances to 13 Cepheids in the LMC which span a period range from 3 to 42 days. From the absolute magnitudes of the...
Classical Cepheid Pulsation Models. X. The Period-Age Relation (2004)
Bono, G., Marconi, M., Cassisi, S., Caputo, F., Gieren, W., Pietrzynski, G.
We present new Period-Age (PA) and Period-Age-Color (PAC) relations for fundamental and first overtone classical Cepheids. Current predictions rely on homogeneous sets of evolutionary and pulsation...
Pietrzynski, G., Gieren, W., Udalski, A., Bresolin, F., Kudritzki, R. P., Soszynski, I., ...
We have obtained mosaic images of NGC 6822 in V and I bands on 77 nights. From these data, we have conducted an extensive search for Cepheid variables over the entire field of the galaxy, and we have...
Gieren, W., Pietrzynski, G., Walker, A., Bresolin, F., Minniti, D., Kudritzki, R. P., ...
In a previous paper, we reported on the discovery of more than a hundred new Cepheid variables in the Sculptor Group spiral NGC 300 from wide-field images taken in the B and V photometric bands at...
Gieren, W., Pietrzynski, G., Walker, A., Bresolin, F., Minniti, D., Kudritzki, R. P., ...
In a previous paper, we reported on the discovery of more than a hundred new Cepheid variables in the Sculptor Group spiral NGC 300 from wide-field images taken in the B and V photometric bands at...
Gieren, W., Pietrzynski, G., Walker, A., Bresolin, F., Minniti, D., Kudritzki, R. P., ...
In a previous paper, we reported on the discovery of more than a hundred new Cepheid variables in the Sculptor Group spiral NGC 300 from wide-field images taken in the B and V photometric bands at...
Pietrzy{ń}ski, G., Gieren, W., Udalski, A.
(Abridged) We present results of deep near-infrared JK imaging of LMC, SMC, and the Carina and Fornax dwarf galaxies. A comparison of the extinction-corrected K-band red clump star magnitudes with...
Double-periodic blue variables in the Magellanic Clouds (2002)
Mennickent, R. E., Pietrzynski, G., Diaz, M., Gieren, W.
We report the discovery, based on an inspection of the OGLE-II database, of a group of blue variables in the Magellanic Clouds showing simultaneously two kinds of photometric variability: a...
Light Curve Analysis of Be Star Candidates in the Small Magellanic Cloud (2002)
Mennickent, R. E., Pietrzynski, G., Gieren, W.
The recent discovery, based on a search of public OGLE data, of Be star candidates in the Small Magellanic Cloud showing spectacular photometric variations (Mennickent et al. 2002), has motivated...
Kundu, A., Majewski, S. R., Rhee, J., Rocha-Pinto, H. J., Polak, A. A., Slesnick, C. L., ...
We describe first results of a spectroscopic probe of selected fields from the Grid Giant Star Survey. Multifiber spectroscopy of several hundred stars in a strip of eleven fields along delta...
We have obtained deep imaging in the near-infrared J and K bands for 2 nearby fields in the bar of the LMC with the ESO NTT telescope, under exquisite seeing conditions. The K, J-K color-magnitude...
Mennickent, R. E., Pietrzynski, G., Gieren, W., Szewczyk, O.
Recently the OGLE experiment has provided accurate light curves and colours for about 2 millions stars in the Small Magellanic Cloud. We have examined this database for its content of Be stars,...
Pietrzy{ń}ski, G., Gieren, W., Fouque, P., Pont, F.
Based on observations of NGC 300, obtained with the Wide-Field Camera at the 2.2 m ESO/MPI telescope during 29 nights spread over a 5.3 month interval, 117 Cepheids and 12 Cepheid candidates were...
Pietrzynski, G., Gieren, W., Udalski, A.
Based on 13 nights of observations of four fields in NGC 300, we have set up an extensive sequence of stars with accurate BVI photometry covering a relatively large (25 x 25 arcmin) region centered...
A Catalog of OB Associations in the spiral galaxy NGC 300 (2001)
Pietrzynski, G., Gieren, W., Fouque, P., Pont, F.
We present results of a search for OB associations in NGC 300. Using an automatic and objective method (PLC technique) 117 objects were found. Statistical tests indicate that our sample is...
A Catalog of OB Associations in the spiral galaxy NGC 300 (2001)
Pietrzynski, G., Gieren, W., Fouque, P., Pont, F.
We present results of a search for OB associations in NGC 300. Using an automatic and objective method (PLC technique) 117 objects were found. Statistical tests indicate that our sample is...
A Catalog of OB Associations in the spiral galaxy NGC 300 (2001)
Pietrzynski, G., Gieren, W., Fouque, P., Pont, F.
We present results of a search for OB associations in NGC 300. Using an automatic and objective method (PLC technique) 117 objects were found. Statistical tests indicate that our sample is...
The dwarf nova RZ Leonis : photometric period, "anti-humps" and normal alpha disk (1999)
Mennickent, R. E., Sterken, C., Gieren, W., Unda, E.
We present results of differential photometry of the dwarf nova RZ Leonis spanning a 11-year baseline. The most striking feature of the light curve is a non-coherent periodic hump of variable...