5 papers
A heterogeneous set of unusual quasars selected from astrometry and broad-band photometry
C. Cheng, K. Valeckas, L. Christensen +7
The aim of this study is to explore methods for how to identify new quasars with different properties with regard to reddening, redshift, the presence of broad absorption lines fro…
SN 2025aico: Early observations of a faint Type IIb supernova with a low-mass envelope
J. -W. Zhao, A. Pastorello, B. Kumar +45
We aimed to investigate the physical properties and the underlying explosion mechanisms of the Type IIb SN 2025aico. Through a comprehensive analysis of early-phase optical light c…
Spectroscopic characterization of a remarkable temporally varying, triple-lensed quasar at z=2.67
Charlie Lind-Thomsen, Kasper E. Heintz, Albert Sneppen +5
Gravitationally lensed quasars are viable cosmic tools for constraining a diversity of fundamental astrophysical phenomena; They enable identification of faint, low-mass supermassi…
Phase-resolved optical spectroscopy of the rapidly varying white dwarf ZTF 1851+1714
C. C. Pedersen, M. R. M. Knudsen, K. Valeckas +3
We report on phase-resolved optical spectroscopy and photometry in the R and B bands of the white dwarf candidate ZTF 185139.81+171430.3. The source has been reported to be variabl…
PyLongslit: a simple manual Python pipeline for processing of astronomical long-slit spectra recorded with CCD detectors
Kostas Valeckas, Johan Peter Uldall Fynbo, Jens-Kristian Krogager +1
We present a new Python pipeline for processing data from astronomical long-slit spectroscopy observations recorded with CCD detectors. The pipeline is designed to aim for simplici…