Spectroscopy of fast rotating stars, with small telescopes

Iraj Safaei,  University of Kashan Observatory

Abstract

It is well-known that increasing the resolving power in spectroscopy, the detectable wavelength range decreases. As a result of this fact also the flux of the photons in each band decreases and this poses the main limitation on the spectroscopy of stars with small telescopes. In the present work the rather small 16 inch diameter telescope of the University of  Kashan Observatory (UKO) has been used to measure stellar rotational velocities with the hydrogen-beta line. Due to the limitation in the total flux received from the stars, we had to measure the rotation speed of the brightest ones of the fast-moving star: Altair, Alderamin, Regulus, Alkaid, Denebola Hereby we compared the rotational Doppler broadening with measurements by other methods  and show that our results are in the acceptable range. In our calculations thermal Doppler broadening only had a slight effect, and we ignored it together with other possible effects for now.

Lecture by Mr. Iraj Safaei, Head of Kashan University Observatory

At “70 years of stellar associations” conference

Wednesday, 27 September 2017

Armenian Academy of Sciences, Yerevan, Armenia