2023A&A...671A..48R


Query : 2023A&A...671A..48R

2023A&A...671A..48R - Astronomy and Astrophysics, volume 671A, 48 (2023/3-1)

Long-term optical variability of the Be/X-ray binary GRO J2058+42.

REIG P., TZOUVANOU A., BLINOV D. and PANTOULAS V.

Abstract (from CDS):

Context. GRO J2058+42 is a transient hard X-ray pulsar that occasionally goes into outburst. The optical counterpart is a poorly studied OB-type companion.
Aims. We investigate the long-term optical variability of the Be/X-ray binary GRO J2058+42 and the possible connection with periods of enhanced X-ray activity.
Methods. We performed an optical spectroscopic and photometric analysis on data collected during about 18 yr. We also present the first optical polarimetric observations of this source.
Results. The long-term optical light curves in the BVRI bands and the evolution of the Hα equivalent width display a sinusoidal pattern with maxima and minima that repeat every ∼9.5 yr. The amplitude of this variability increases as the wavelength increases from 0.3 mag in the B band to 0.7 in the I band. The Hα equivalent width varied from about -0.3 to -15 Å. We found a significant decrease in the polarization degree during the low optical state. The intrinsic polarization degree changed by ∼1% from maximum to minimum. The optical maxima occur near periods of enhanced X-ray activity and are followed by a drop in the optical emission. Unlike many other Be/X-ray binaries, GRO J2058+42 does not display V/R variability.
Conclusions. The long-term optical variability agrees with the standard model of a Be/X-ray binary, where the circumstellar disk of the Be star grows and dissipates on timescales of 9-10 yr. We find that the dissipation of the disk started after a major X-ray outburst. However, the stability of the Hα line shape as a double-peak profile and the lack of asymmetries suggest the absence of a warped disk and argue against the presence of a highly distorted disk during major X-ray outbursts.

Abstract Copyright: © The Authors 2023

Journal keyword(s): stars: neutron - stars: emission-line, Be - X-rays: binaries

Simbad objects: 11

goto Full paper

goto View the references in ADS

Number of rows : 11
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024
#notes
1 V* V635 Cas HXB 01 18 31.9704955824 +63 44 33.072603144 17.05 16.64 15.19 14.34 13.22 B0.2Ve 746 0
2 SWIFT J0243.6+6124 Psr 02 43 40.4252869512 +61 26 03.757456824   13.71 12.84 12.57   O9.5Ve 144 0
3 V* BQ Cam HXB 03 34 59.9116110096 +53 10 23.296879776   17.16 15.42 14.26 13.04 O8.5Ve 481 1
4 LS V +44 17 HXB 04 40 59.3296237272 +44 31 49.258049376 11.02 11.42 10.73 10.28 9.76 B0.2Ve 140 0
5 HD 245770 HXB 05 38 54.5748918624 +26 18 56.836952784 9.30 9.84 9.39 8.77 8.30 O9/B0III/Ve 985 0
6 Gaia DR3 2065653598916381568 * 20 58 46.0512717271 +41 45 57.567438398           ~ 1 0
7 GRO J2058+42 HXB 20 58 47.5371521256 +41 46 37.180486128   15.97 14.74 14.74 13.35 O9.5-B0IV-Ve 87 0
8 USNO-A2.0 1275-14426256 * 20 58 53.5121241864 +41 46 27.576571620   16.8   13.9   ~ 2 0
9 Gaia DR3 2065652671203453696 * 20 59 04.9099305177 +41 45 53.730919965           ~ 1 0
10 SAX J2103.5+4545 HXB 21 03 35.7100848936 +45 45 05.568751692   15.34 14.20 13.991 12.75 B0Ve 185 0
11 IGR J21347+4737 HXB 21 34 20.3718881736 +47 38 00.205959228   14.699 14.217 13.80 13.42 B3V 32 0

To bookmark this query, right click on this link: simbad:objects in 2023A&A...671A..48R and select 'bookmark this link' or equivalent in the popup menu