Ultraviolet Spectral Behavior of UX Ari with Periodic Flaring Activity

Sanad, M.R.; Zead, I.; Abdel-Sabour, Mohamed

doi:10.1007/s10511-021-09692-1

Cited by 3 publications

(2 citation statements)

References 14 publications

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“…Tables 2, 3, 4, 5, 6 show the line fluxes and flaring values of O I, C II, C IV, He II and C I emission lines for II Peg respectively. We notice that the occurrence of flaring activity of II Peg is not periodic as with UX Ari (Sanad et al 2021). The flux increases of studied emission lines reached about six and nine times the quiescent values and the activity of all mentioned emission lines is around phases 0.59 and 0.92 above the normal spectral behavior as shown in Figure 3.…”

Section: Ultraviolet Behavior Of Spectral Lines and Their Sourcementioning

confidence: 63%

“…RS Canum Venaticorum (RS CVn) variable stars are active chromospheric binary systems with large starspots, intense chromospheric plages, coronal X-ray emission and microwave emissions, as well as enhanced flares in all wavelengths from optical, radio, ultraviolet (UV) and X-ray regions (Sanad et al 2021;Hall 1976;Tautvaisiene & Barisevicius 2012).…”

Section: Introductionmentioning

confidence: 99%

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Spectral behavior and Flaring Activity of II Peg in the Ultraviolet

Sanad¹

2022

Res. Astron. Astrophys.

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We have investigated the spectral behavior of II Peg binary system in the ultraviolet band by using International Ultraviolet Explorer (IUE) observations over the period (1979 – 1993). The ultraviolet observations show indication of flare activity in the chromosphere and transition region with their enhanced spectral lines. Before and after the flare activity the ultraviolet spectral lines show low, intermediate and high flux. The spectral behavior is compared with previous studies. We detect prominent flare activity in (1989, 1990, 1992). Before and after this period there is a gradual clear decrease in the level of activity. The reddening of II Peg was estimated from 2200 Å absorption feature to be E (B-V) = 0.10 ± 0.02. We determined the mean rate of mass loss to be ~ 1 × 10-8 M yr-1, the mean temperature of the emitting source to be ~ 1.1 × 104 K, and the ultraviolet luminosity to be ~ 7 × 1027 erg s-1. We attributed the spectral variations to a cyclic behavior of the underlying magnetic dynamo and the prominent activity can be interpreted by the model of two – ribbon flare.

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Section: Ultraviolet Behavior Of Spectral Lines and Their Sourcementioning

confidence: 63%

Section: Introductionmentioning

confidence: 99%