Grzegorz Pietrzynski

The Araucaria Project. The Distance to the Small Magellanic Cloud from Near-Infrared Photometry of RR Lyrae Variables (2009)

Szewczyk, Olaf, Pietrzynski, Grzegorz, Gieren, Wolfgang, Ciechanowska, Anna, Bresolin, Fabio, Kudritzki, Rolf-Peter

We have obtained deep infrared J and K band observations of nine 4.9x4.9 arcmin fields in the Small Magellanic Cloud (SMC) with the ESO New Technology Telescope equipped with the SOFI infrared...

Extragalactic chemical abundances: do HII regions and young stars tell the same story? The case of the spiral galaxy NGC 300 (2009)

Bresolin, Fabio, Gieren, Wolfgang, Kudritzki, Rolf-Peter, Pietrzynski, Grzegorz, Urbaneja, Miguel A., Carraro, Giovanni

(Abridged) We have obtained new spectrophotometric data for 28 HII regions in the spiral galaxy NGC 300, a member of the nearby Sculptor Group. The detection of auroral lines, including [OIII]4363,...

The Araucaria Project. The Distance of the Large Magellanic Cloud from Near-Infrared Photometry of RR Lyrae Variables (2008)

Szewczyk, Olaf, Pietrzynski, Grzegorz, Gieren, Wolfgang, Storm, Jesper, Walker, Alistair, Rizzi, Luca, ...

We have obtained deep infrared $J$ and $K$ band observations of five fields located in the Large Magellanic Cloud (LMC) bar with the ESO New Technology Telescope equipped with the SOFI infrared...

VLT spectroscopy of blue supergiants in IC 1613 (2007)

Bresolin, Fabio, Urbaneja, Miguel A., Gieren, Wolfgang, Pietrzynski, Grzegorz, Kudritzki, Rolf-Peter

We present multi-object spectroscopy of young, massive stars in the Local Group galaxy IC 1613. We provide the spectral classification and a detailed spectral catalog for 54 OBA stars in this galaxy....

Millimagnitude Photometry for Transiting Extrasolar Planetary Candidates IV: The Puzzle of the Extremely Red OGLE-TR-82 Primary Solved (2007)

Hoyer, Sergio, Alegria, Sebastian Ramirez, Ivanov, Valentin D., Minniti, Dante, Pietrzynski, Grzegorz, Ruiz, Maria Teresa, ...

We present precise new V, I, and K-band photometry for the planetary transit candidate star OGLE-TR-82. Good seeing V-band images acquired with VIMOS instrument at ESO VLT allowed us to measure...

ESO Large Programme 666 on OGLE transits: I. Accurate radius of the planets OGLE-TR-10b and OGLE-TR-56b with VLT deconvolution photometry (2007)

Pont, Frederic, Moutou, Claire, Gillon, Michael, Udalski, Andrzej, Bouchy, Francois, Fernandes, Joao, ...

Transiting planets are essential to study the structure and evolution of extra-solar planets. For that purpose, it is important to measure precisely the radius of these planets. Here we report new...

Millimagnitude Photometry for Transiting Extrasolar Planetary Candidates: II. Transits of OGLE-TR-113-b in the Optical and Near-IR (2007)

Díaz, Rodrigo F., Ramírez, Sebastián, Fernández, José Miguel, Gallardo, José, Gieren, Wolfgang, Ivanov, Valentin D., ...

We present precise V and Ks-band transit photometry for the planetary host star OGLE-TR-113. Using the Ks-band photometry, we confirm the dwarf nature of OGLE-TR-113, and obtain new estimates for its...

Millimagnitude Photometry for Transiting Extrasolar Planetary Candidates III: Accurate Radius and Period for OGLE-TR-111-b (2007)

Minniti, Dante, Fernández, José Miguel, Díaz, Rodrigo F., Udalski, Andrzej, Pietrzynski, Grzegorz, Gieren, Wolfgang, ...

We present accurate V-band photometry for a planetary transit of OGLE-TR-111 acquired with VIMOS at the ESO Very Large Telescope. The measurement of this transit allows to refine the planetary...

The `666' collaboration on OGLE transits: I. Accurate radius of the planets OGLE-TR-10b and OGLE-TR-56b with VLT deconvolution photometry (2006)

Pont, Frederic, Moutou, Claire, Gillon, Michael, Udalski, Andrzej, Bouchy, Francois, Fernandes, Joao, ...

Transiting planets are essential to study the structure and evolution of extra-solar planets. For that purpose, it is important to measure precisely the radius of these planets. Here we report new...

Millimagnitude optical photometry for the transiting planetary candidate OGLE-TR-109 (2006)

Fernández, José Miguel, Minniti, Dante, Pietrzynski, Grzegorz, Gieren, Wolfgang, Ruiz, María Teresa, Zoccali, Manuela, ...

We present precise V-band photometry for the low-amplitude transit candidate star OGLE-TR-109. This is an extreme case among the transiting candidates found by the OGLE group because of the early...

The Araucaria Project. VLT spectra of blue supergiants in WLM: classification and first abundances (2006)

Bresolin, Fabio, Pietrzynski, Grzegorz, Urbaneja, Miguel A., Gieren, Wolfgang, Kudritzki, Rolf-Peter, Venn, Kim A.

As part of the Araucaria Project, we present the first spectral catalog of supergiant stars in the Local Group dwarf irregular galaxy WLM. In assigning a spectral classification to these stars we...

Millimagnitude Optical Photometry for the Transiting Planetary Candidate OGLE-TR-109 (2006)

Fernandez, Jose Miguel, Minniti, Dante, Pietrzynski, Grzegorz, Gieren, Wolfgang, Ruiz, Maria Teresa, Zoccali, Manuela, ...

We present precise V-band photometry for the low-amplitude transit candidate star OGLE-TR-109. This is an extreme case among the transiting candidates found by the OGLE group because of the early...

The Araucaria Project: The Distance to NGC 300 from the Red Giant Branch Tip using HST/ACS imaging (2005)

Rizzi, Luca, Bresolin, Fabio, Kudritzki, Rolf-Peter, Gieren, Wolfgang, Pietrzynski, Grzegorz

We have used the Advanced Camera for Surveys on board the Hubble Space Telescope to obtain deep photometry of the NGC 300 spiral galaxy in the Sculptor group. The results have been used to derive an...

Evidence for a Universal Slope of the Period-Luminosity Relation from Direct Distances to Cepheids in the LMC (2005)

Gieren, Wolfgang, Storm, Jesper, Barnes III, Thomas G., Fouque, Pascal, Pietrzynski, Grzegorz, Kienzle, Francesco

We have applied the infrared surface brightness (ISB) technique to derive distances to 13 Cepheid variables in the LMC which have periods from 3-42 days. The corresponding absolute magnitudes define...

The Araucaria Project: The effect of blending on the Cepheid distance to NGC 300 from Advanced Camera for Surveys images (2005)

Bresolin, Fabio, Pietrzynski, Grzegorz, Gieren, Wolfgang, Kudritzki, Rolf-Peter

We have used the Advanced Camera for Surveys aboard the Hubble Space Telescope to obtain F435W, F555W and F814W single-epoch images of six fields in the spiral galaxy NGC 300. Taking advantage of the...

A transiting extrasolar giant planet around the star OGLE-TR-113 (2004)

Konacki, Maciej, Torres, Guillermo, Sasselov, Dimitar D., Pietrzynski, Grzegorz, Udalski, Andrzej, Jha, Saurabh, ...

We report the independent discovery of a new extrasolar transiting planet around OGLE-TR-113, a candidate star from the Optical Gravitational Lensing Experiment. Small radial-velocity variations have...

On the photometric variability of blue supergiants in NGC 300 and its impact on the Flux-weighted Gravity-Luminosity Relationship (2003)

Bresolin, Fabio, Pietrzynski, Grzegorz, Gieren, Wolfgang, Kudritzki, Rolf-Peter, Przybilla, Norbert, Fouque', Pascal

We present a study of the photometric variability of spectroscopically confirmed supergiants in NGC 300, comprising 28 epochs extending over a period of five months. We find 15 clearly...

Discovery and quantitative spectral analysis of an Ofpe/WN9 (WN11) star in the Sculptor spiral galaxy NGC 300 (2002)

Bresolin, Fabio, Kudritzki, Rolf-Peter, Najarro, Francisco, Gieren, Wolfgang, Pietrzynski, Grzegorz

We have discovered an Ofpe/WN9 (WN11 following Smith et al.) star in the Sculptor spiral galaxy NGC 300, the first object of this class found outside the Local Group, during a recent spectroscopic...

Spectroscopy of blue supergiants in NGC 300 (2001)

Bresolin, Fabio, Gieren, Wolfgang, Kudritzki, Rolf-Peter, Pietrzynski, Grzegorz, Przybilla, Norbert

We have obtained VLT low-resolution (~5 A) multi-object spectroscopy in the 4,000-5,000 A spectral range of about 70 blue supergiant candidates in the Sculptor Group spiral galaxy NGC 300. We present...