RT Journal Article
T1 IGR J19552+0044: A new asynchronous short period polar Filling the gap between intermediate and ordinary polars
A1 Tovmassian, G.
A1 González Buitrago, D.
A1 Thorstensen, J. R.
A1 Miguel Agustino, Enrique de
AB Context. Based on XMM-Newton X-ray observations IGR J19552+0044 appears to be either a pre-polar or an asynchronous polar.Aims. We conducted follow-up optical observations to identify the sources and periods of variability precisely and to classify thisX-ray source correctly.Methods. Extensive multicolor photometric and medium- to high-resolution spectroscopy observations were performed and periodsearch codes were applied to sort out the complex variability of the object.Results. We found firm evidence of discording spectroscopic (81.29 ± 0.01 m) and photometric (83.599 ± 0.002 m) periods thatwe ascribe to the white dwarf (WD) spin period and binary orbital period, respectively. This confirms that IGR J19552+0044 isan asynchronous polar. Wavelength dependent variability and its continuously changing shape point at a cyclotron emission from amagnetic WD with a relatively low magnetic field below 20 MG.Conclusions. The difference between the WD spin period and the binary orbital period proves that IGR J19552+0044 is a polar withthe largest known degree of asynchronism (0.97 or 3%).
PB EDP Sciences
SN 0004-6361
YR 2017
FD 2017-08
LK http://hdl.handle.net/10272/18416
UL http://hdl.handle.net/10272/18416
LA eng
NO Tovmassian, G., González Buitrago, D., Thorstensen, J.R. ... de Miguel  Agustino, E. (2017) . IGR J19552+0044: A new asynchronous short period polar Filling the gap between intermediate and ordinary polars.  Astronomy & Astrophysics, 608, A36. DOI:  https://doi.org/10.1051/0004-6361/201731323
DS Repositorio Institucional de la Universidad de Huelva
RD 30 may 2026