Microlensing of radially pulsating stars

Abstract

Here, we study the microlensing of radially pulsating stars. Discerning and characterizing the properties of distant, faint pulsating stars is achievable through high-cadence microlensing observations. Combining stellar variability period with microlensing gives the source distance, type, and radius and helps better determine the lens parameters. Considering periodically variations in their radius and surface temperature, their microlensing light curves are resulted from multiplication of the magnification factor with variable finite size effect by the intrinsic brightness curves of pulsing source. The variable finite source size due to pulsation can be significant for transit and single microlensing and while caustic-crossing features. This kind of deviation in the magnification factor is considerable when the ratio of the source radius to the projected lens-source distance is in the range of ${\rho }_{\star }/u\in [0.4,10]$ and its duration is short and in the same order of the time of crossing the source radius. Other deviations due to variable source intensity and its area make colored and periodic deviations which are asymmetric with respect to the signs of pulsation phase. The positive phases makes deviations with larger amplitude that negative phase. These deviations dominate in filters with short wave lengths (e.g., $B-$band). The position of magnification peaks in microlensing of variable stars varies and this displacement differs in different filters.

10 pages, 6 figures; Accepted to be published by MNRAS

References in corpus (5)

• Microlensing optical depth and event rate toward the Galactic bulge from 8 yr of OGLE-IV observations
• OGLE-III Microlensing Events and the Structure of the Galactic Bulge
• Blue large-amplitude pulsators as a new class of variable stars
• OGLE-2017-BLG-1186: first application of asteroseismology and Gaussian processes to microlensing
• Removing the Microlensing Blending-Parallax Degeneracy Using Source Variability

Cited by in corpus (5)

• On the detection of free-floating planets through microlensing towards the Magellanic Clouds
• Non-radially pulsating stars as microlensing sources
• Identifying low-amplitude pulsating stars through microlensing observations
• Galactic microlensing by acoustic Schwarzschild black holes
• Variation of the stellar color in high-magnification and caustic-crossing microlensing events