ANALISIS VARIASI SPEKTRUM GARIS H-ALFA BINTANG B-EMISI PADA BERBAGAI SUB KELAS SPEKTRUM B

• Main Author: Agesti Arifiana Putri, Zeni
• Format: Final Project
• Language: Indonesia
• Subjects: Astronomi
• Online Access: https://digilib.itb.ac.id/gdl/view/55267
• Institution: Institut Teknologi Bandung

Be stars are non-giant spectral class B stars that have or are currently having emission lines in their spectrum. The selected object was based on a paper from Slettebak, et al (1992) which amounted to 41 program stars. However, there is 1 star program, namely HD 68980 which does not have good enough spectrum data in the BeSS database. there are 5 stars that still show a single peak spectrum profile from 1989 to 2020, then there are 8 stars that still show a double peak spectrum profile, there are 2 star data showing shell spectrum profiles, and 26 other stars showing variations in spectrum profiles that change. change from 1989 to the latest data available in the BeSS. The data used in the analysis are data from Slettebak et al. (1992) then continued with the data obtained from the BeSS database. Parameter values used are FWHM, EW, E/C, V/R and the separation of the two peaks. Only data that is at the H? wavelength and has a high resolution is selected. The value of the separation of the two peaks must then be converted from Angstroms to km/s to get the value of the outer radius of the star envelope. Variations in V/R and EW parameters are quite appropriate or relevant to existing references, but new references need to be found because variations in Be stars can vary with time. The early type Be star has a fairly wide V/R variation than the late type. EW parameter variation has a negative gradient so that it will decrease towards the late type Be star. The FWHM and E/C variations do not show a clear trend. Then, of all the data that can produce the value of the outer radius of the star envelope, there are 70% of the total data that have values in the range produced by Slattebak, et al., (1992) which ranges from 7-19 R*. The value of the outer radius is proportional to the rotational velocity of the star. The influence of the rotational velocity of the star is quite high, causing the radius of the star envelope to be even greater. Key words : Be Stars, H?, Variation, Radius, Rotational Velocity