Publications (24)
Asteroseismology of RR Lyrae stars with non-radial modes
H. Netzel, R. Smolec
The additional signals observed in the frequency spectra of the first-overtone RR Lyrae stars, that form a period ratio around 0.61 with the period of the first overtone, are a com…
Double-mode radial-non-radial RR Lyrae stars. OGLE-IV photometry of two high cadence fields in the Galactic bulge
H. Netzel, R. Smolec, P. Moskalik
We analyse the OGLE-IV photometry of the first overtone and double-mode RR Lyrae stars (RRc/RRd) in the two fields towards the Galactic bulge observed with high cadence. In 27 per…
Time series analysis of bright TESS RRc stars: Additional modes, phase variations and more
J. M. BenkÅ, E. Plachy, H. Netzel +3
Using two years of data from the TESS space telescope, we have investigated the time series of 633 overtone pulsating field RR Lyrae (RRc) stars. The majority of stars (82.8 per ce…
Modeling of multimode radially pulsating High-Amplitude Delta Scuti stars from the OGLE Galactic bulge sample
H. Netzel, R. Smolec
Thanks to relatively firm mode identification, possible based on period ratios only, High Amplitude Delta Scuti Stars pulsating in at least three radial modes are promising targets…
Double-mode radial-non-radial RR Lyrae stars in the OGLE photometry of the Galactic bulge
H. Netzel, R. Smolec, P. Moskalik
Non-radial modes are excited in classical pulsators, both in Cepheids and in RR Lyrae stars. Firm evidence come from the first overtone pulsators, in which additional shorter perio…
Detailed asteroseismic modeling of RR Lyrae stars with non-radial modes
H. Netzel, L. Molnar, M. Joyce
Photometric observations from the last decade have revealed additional low-amplitude periodicities in many classical pulsators that are likely due to pulsations in non-radial modes…
Over 10 000 Delta Scuti Stars toward the Galactic Bulge from OGLE-IV
P. Pietrukowicz, I. Soszynski, H. Netzel +12
We present a collection of 10 111 genuine delta Sct-type pulsating variable stars detected in the OGLE-IV Galactic bulge fields. In this sample, 9835 variables are new discoveries.…
Petersen Diagram Revolution
R. Smolec, W. Dziembowski, P. Moskalik +4
Over the recent years, the Petersen diagram for classical pulsators, Cepheids and RR Lyr stars, populated with a few hundreds of new multiperiodic variables. We review our analyses…
TESS observations of Cepheid stars: first light results
E. Plachy, A. Pál, A. Bódi +33
We present the first analysis of Cepheid stars observed by the TESS space mission in Sectors 1 to 5. Our sample consists of 25 pulsators: ten fundamental mode, three overtone and t…
Non-radial modes in classical Cepheids. What to look for in spectroscopy?
H. Netzel, K. Kolenberg
Recent photometric observations of first-overtone classical Cepheids and RR Lyrae stars have led to the discovery of additional frequencies showing a characteristic period ratio of…
Non-radial Pulsations in RR Lyrae Stars from the OGLE Collection
H. Netzel, R. Smolec
RR Lyrae stars are classical pulsating stars. They pulsate mostly in the radial fundamental mode (RRab stars), in the radial first overtone mode (RRc stars), or in both modes simul…
Full orbital solution for the binary system in the northern Galactic disc microlensing event Gaia16aye
Åukasz Wyrzykowski, P. Mróz, K. A. Rybicki +182
Gaia16aye was a binary microlensing event discovered in the direction towards the northern Galactic disc and was one of the first microlensing events detected and alerted to by the…
Frequency analysis of the first-overtone RR Lyrae stars based on the Extended Aperture Photometry from the K2 data
H. Netzel, L. Molnar, E. Plachy +1
Additional low-amplitude signals are observed in many RR Lyrae stars, beside the pulsations in radial modes. The most common ones are short-period signals forming a period ratio of…
Discovery of a new group of double-periodic RR Lyrae stars in the OGLE-IV photometry
H. Netzel, R. Smolec, W. Dziembowski
We report the discovery of a new group of double-periodic RR Lyrae stars from the analysis of the OGLE-IV Galactic bulge photometry. In 11 stars identified in the OGLE catalog as f…
Blazhko effect and the Petersen diagram
H. Netzel
Pulsations in RR Lyrae stars and classical Cepheids were thought to be relatively simple since they typically pulsate only in one or two radial modes. This picture changes at a clo…
Frequency analysis of Delta Scuti stars towards the Galactic bulge
H. Netzel, P. Pietrukowicz, I. SoszyÅski +1
We have performed a frequency analysis of 10,092 Delta Scuti-type stars detected in the fourth phase of the Optical Gravitational Lensing Experiment (OGLE) towards the Galactic bul…
On the incidence rate of RR Lyrae stars with non-radial modes
H. Netzel, V. Varga, R. Szabo +2
Over the recent years, additional low-amplitude non-radial modes were detected in many of the first-overtone RR Lyrae stars. These non-radial modes form a characteristic period rat…
Gaia 18dvy: a new FUor in the Cygnus OB3 association
E. Szegedi-Elek, P. Ãbrahám, L. Wyrzykowski +59
We present optical-infrared photometric and spectroscopic observations of Gaia18dvy, located in the Cygnus OB3 association at a distance of 1.88 kpc. The object was noted by the Ga…
The VELOCE modulation zoo II. Humps and splitting patterns in spectral lines of classical Cepheids
H. Netzel, R. I. Anderson, G. Viviani
Line splitting in spectral lines is observed in various types of stars due to phenomena such as shocks, spectroscopic binaries, magnetic fields, spots, and non-radial modes. In pul…
The VELOCE Modulation Zoo I. Spectroscopic detection of non-radial modes in the first-overtone Cepheids BG Crucis, QZ Normae, V0391 Normae, and V0411 Lacertae
H. Netzel, R. I. Anderson, G. Viviani
The photometric observations from the recent decade revolutionized our view on classical pulsators. Low-amplitude signals have been detected photometrically in addition to the domi…
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…
Exploring Low-Amplitude Variability in First Overtone Cepheids with TESS
E. Plachy, H. Netzel, A. Bódi
Classical Cepheid stars that pulsate in the first overtone radial mode often exhibit additional periodicities at the millimagnitude level. Extensive studies of the OGLE data of the…
Frequency analysis of OGLE-IV photometry for classical Cepheids in Galactic fields: non-radial modes and modulations
R. S. Rathour, R. Smolec, H. Netzel
We analyse photometry of 2000 Galactic Cepheids available in the OGLE Collection of Variable Stars. We analyse both Galactic disk and Galactic bulge fields; stars classified…
Reddening maps of the Magellanic Clouds using spectral energy distribution fitting of red giants
H. Netzel, G. PietrzyÅski, M. Górski +9
Robust reddening maps of the Large and Small Magellanic Clouds (LMC/SMC) are crucial for a wide range of astrophysical studies, including the calibration of the cosmic distance lad…