6 papers
The nature of ASASSN-24fw's occultation: modelling the event as dimming by optically thick rings around a sub-stellar companion
Sarang Shah, Jonathan P. Marshall, Carlos del Burgo +12
ASASSN-24fw is a main-sequence F-type star that experienced a rapid and long-lasting dimming event beginning in late 2024 and continuing until mid 2025. Its pre-dimming spectral en…
RR Lyrae stars with variable mean magnitudes
Gergely Hajdu, Johanna Jurcsik, Márcio Catelan +6
Context. A number of RR Lyrae stars show variable mean magnitudes in the OGLE survey light curves of the Galactic bulge. Hitherto this phenomenon was not studied, as it was general…
HALO I: Photometric continuum reverberation mapping of Fairall 9
Amit Kumar Mandal, Francisco Pozo Nuñez, Vikram Kumar Jaiswal +23
We investigate the origin of inter-band continuum time delays in active galactic nuclei (AGNs) to study the structure and properties of their accretion disks. We aim to measure the…
Distance to the Globular Cluster M 3 from the Infrared Surface Brightness Technique applied to RR Lyrae stars
BartÅomiej Zgirski, Wolfgang Gieren, Grzegorz PietrzyÅski +10
The Infrared Surface Brightness (IRSB) technique is a specific application of the Baade-Wesselink method. Given a proper calibration, well covered optical and near-infrared photome…
Secondary standards in the UKIRT faint standard fields
Marek Górski, Grzegorz PietrzyÅski, Paulina Karczmarek +8
We present precise J- and K-band photometric measurements for 128 near-infrared secondary standard stars, located in the 19 UKIRT/MKO primary faint standard fields. The data were c…
Non-evolutionary effects on period change in Magellanic Cepheids II. Empirical constraints on non-linear period changes
Rajeev Singh Rathour, RadosÅaw Smolec, Gergely Hajdu +5
Classical Cepheids are not only excellent standard candles, but also invaluable tools to test stellar evolution and pulsation theories. Rates of their pulsation period change, quan…