112 citations · 1.1k across the 55 of their papers we have counts for
54 papers
HALO II: Constraining Hubble constant through continuum delay fitting of Fairall 9
Amit Kumar Mandal, Francisco Pozo Nuñez, Vikram Kumar Jaiswal +28
The Hubble tension remains one of the most significant unresolved problems in modern cosmology. A key question is whether it may arise from underestimated systematic uncertainties…
Finding the elusive RR Lyrae companions via speckle imaging
R. Salinas, V. Kalari, G. Hajdu +25
Despite their key role in astrophysics, the binary properties of RR Lyrae stars (RRL) remain almost completely unknown since only a single RRL is confirmed as belonging to a binary…
Period-Luminosity Relations, projection factor and radii of Anomalous Cepheids
Piotr Wielgórski, Grzegorz Pietrzyński, Wolfgang Gieren +24
Anomalous Cepheids are radially pulsating stars observed in dwarf galaxies, the Galactic bulge and halo, and globular clusters. Similarly to other radially pulsating stars, they ca…
Photometric metallicities of fundamental-mode RR Lyr stars from Gaia -band photometry of globular-cluster variables
Johanna Jurcsik, Gergely Hajdu
Photometric metallicity formulae of fundamental-mode RR Lyr (RRab) stars are presented using globular-cluster data exclusively. The aim is to check whether this selection may help…
Roman Early-Definition Astrophysics Survey Opportunity: Galactic Roman Infrared Plane Survey (GRIPS)
Roberta Paladini, Catherine Zucker, Robert Benjamin +67
A wide-field near-infrared survey of the Galactic disk and bulge/bar(s) is supported by a large representation of the community of Galactic astronomers. The combination of sensitiv…
Period-Luminosity Relations for Galactic classical Cepheids in the Sloan bands
Weronika Narloch, Gergely Hajdu, Grzegorz Pietrzynski +6
We present the first period-luminosity (PL) and period-Wesenheit (PW) relations in the Sloan-Pans-STARRS gP1rP1iP1 bands for classical fundamental mode Cepheids in the Milky Way. W…
The Araucaria Project: Improving the cosmic distance scale
The Araucaria Project, :, G. Pietrzyński +21
The book consists of a number of short articles that present achievements of the Araucaria members, collaborators, and friends, in various aspects of distance determinations and re…
New Near-Infrared Period-Luminosity-Metallicity Relations for Galactic RR Lyrae Stars Based on Gaia EDR3 Parallaxes
Bartłomiej Zgirski, Grzegorz Pietrzyński, Marek Górski +13
We present new period-luminosity and period-luminosity-metallicity relations for Galactic RR Lyrae stars based on a sample of 28 pulsators located at distances up to kpc from…
Synthetic Population of Binary Cepheids. II. The effect of companion light on the extragalactic distance scale
Paulina Karczmarek, Gergely Hajdu, Grzegorz Pietrzyński +5
Because of their period-luminosity relation (PLR), classical Cepheids play a key role in the calibration of the extragalactic distance scale and the determination of the Hubble-Lem…
HARPS-N high spectral resolution observations of Cepheids II. The impact of the surface-brightness color relation on the Baade-Wesselink projection factor of eta Aql
N. Nardetto, W. Gieren, J. Storm +16
The Baade-Wesselink (BW) method of distance determination of Cepheids is used to calibrate the distance scale. Various versions of this method are mainly based on interferometry an…
Discovery of a binary-origin classical Cepheid in a binary system with a 59-day orbital period
Bogumił Pilecki, Ian B. Thompson, Felipe Espinoza-Arancibia +8
We report the discovery of a surprising binary configuration of the double-mode Cepheid OGLE-LMC-CEP-1347 pulsating in the first (P_1=0.690d) and second overtone (P_2=0.556d) modes…
Evolved eclipsing binary systems in the Galactic bulge: Precise physical and orbital parameters of OGLE-BLG-ECL-305487 and OGLE-BLG-ECL-116218
K. Suchomska, D. Graczyk, C. Gałan +17
Our goal is to determine, with high accuracy, the physical and orbital parameters of two double-lined eclipsing binary systems, where the components are two giant stars. We also ai…
Period Change Rates of Large Magellanic Cloud Cepheids using MESA
F. Espinoza-Arancibia, M. Catelan, G. Hajdu +8
Pulsating stars, such as Cepheids and RR Lyrae, offer us a window to measure and study changes due to stellar evolution. In this work, we study the former by calculating a set of e…
Surface brightness-colour relations of dwarf stars from detached eclipsing binaries -- I. Calibrating sample
D. Graczyk, G. Pietrzyński, C. Galan +19
Surface brightness -- colour relations (SBCRs) are very useful tools for predicting the angular diameters of stars. They offer the possibility to calculate very precise spectrophot…
Metallicities and ages for star clusters and their surrounding fields in the Large Magellanic Cloud
W. Narloch, G. Pietrzyński, W. Gieren +15
We study 147 star clusters in the Large Magellanic Cloud (LMC) in order to determine their mean metallicities and ages, as well as the mean metallicities of 80 surrounding fields.…
Synthetic population of binary Cepheids. I. The effect of metallicity and initial parameter distribution on characteristics of Cepheids' companions
Paulina Karczmarek, Radosław Smolec, Gergely Hajdu +5
The majority of classical Cepheids are binary stars, yet the contribution of companions' light to the total brightness of the system has been assumed negligible and lacked a thorou…
An absolute calibration of the near-infrared Period-Luminosity Relations of Type II Cepheids in the Milky Way and in the Large Magellanic Cloud
Piotr Wielgórski, Grzegorz Pietrzyński, Bogumił Pilecki +29
We present time-series photometry of 21 nearby Type II Cepheids in the near-infrared J, H and Ks passbands. We use this photometry, together with the Third Gaia Early Data Release…
Period Change Rates in Large Magellanic Cloud Cepheids Revisited
N. Rodríguez-Segovia, G. Hajdu, M. Catelan +10
The period-change rate (PCR) of pulsating variable stars is a useful probe of changes in their interior structure, and thus of their evolutionary stages. So far, the PCRs of Classi…
Studies of RR Lyrae Variables in Binary Systems. I.: Evidence of a Trimodal Companion Mass Distribution
Gergely Hajdu, Grzegorz Pietrzyński, Johanna Jurcsik +6
We present 87 candidates for RR Lyrae variable stars in binary systems, based on our new search using the light-travel time effect (LTTE) and observed - calculated () diagrams…
The Araucaria Project. Distances to Nine Galaxies Based on a Statistical Analysis of their Carbon Stars (JAGB Method)
Bartłomiej Zgirski, Grzegorz Pietrzyński, Wolfgang Gieren +13
Our work presents an independent calibration of the J-region Asymptotic Giant Branch (JAGB) method using Infrared Survey Facility (IRSF) photometric data and a custom luminosity fu…
On the photometric metallicity of Oosterhoff-type I and II RRab stars
Johanna Jurcsik, Gergely Hajdu, Áron Juhász
We are revising the consistency of photometric metallicity formulae widely used for fundamental-mode RR Lyrae (RRab) variables, based on their V- and I-band light curves, published…
The surface brightness - colour relations based on eclipsing binary stars and calibrated with Gaia EDR3
D. Graczyk, G. Pietrzyński, C. Gałan +23
The surface brightness -- colour relation (SBCR) is a basic tool in establishing precise and accurate distances within the Local Group. Detached eclipsing binary stars with accurat…
The Araucaria Project: Deep near-infrared photometric maps of Local and Sculptor Group galaxies. I. Carina, Fornax, Sculptor
Paulina Karczmarek, Grzegorz Pietrzyński, Wolfgang Gieren +12
Deep near-infrared - and -band photometry of three Local Group dwarf spheroidal galaxies: Fornax, Carina, and Sculptor, is made available for the community. Until now, these…
Metallicities and ages for 35 star clusters and their surrounding fields in the Small Magellanic Cloud
W. Narloch, G. Pietrzyński, W. Gieren +13
In this work we study 35 stellar clusters in the Small Magellanic Cloud (SMC) in order to provide their mean metallicities and ages. We also provide mean metallicities of the field…