Short-term spectral variability in AB Aurigae: Clues for activity in Herbig AE stars. II - The CA II K line

Abstract

view Abstract Citations (63) References (29) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Short-Term Spectral Variability in AB Aurigae: Clues for Activity in Herbig AE Stars. II. The CA II K Line Catala, C. ; Felenbok, P. ; Czarny, J. ; Talavera, A. ; Boesgaard, A. M. Abstract The Herbig Ae star AB Aur (A0ep) was monitored with the CFH 3.6 m and the Observatoire de Haute-Provence 1.52 m telescopes in the Ca II K line, for six nights in 1982 October. Some of the 39 recorded spectra were simultaneous with ultraviolet spectra obtained with IUE. The Ca II K line is variable and modulated with a period of 32±4 hours, corresponding to the estimated rotation period of the star. The difference between the 45 hour period found in the Mg II data (Paper I) and the 32 hour period in the Ca II data is assumed as due to a differential rotation in the envelope of the star. This differential rotation allows an estimate of upper limits for the magnetic field and the Alfvén radius in the envelope of AB Aur, as well as for the rate of angular-momentum loss. Publication: The Astrophysical Journal Pub Date: September 1986 DOI: 10.1086/164551 Bibcode: 1986ApJ...308..791C Keywords: A Stars; Abundance; B Stars; Line Spectra; Stellar Spectra; Stellar Spectrophotometry; Calcium; Emission Spectra; K Lines; Red Shift; Stellar Rotation; Astrophysics; STARS: EMISSION-LINE; STARS: INDIVIDUAL CONSTELLATION NAME: AB AURIGAE; STARS: ROTATION; STARS: SPECTRUM VARIABLES full text sources ADS | data products SIMBAD (1) Related Materials (1) Part 1: 1986ApJ...303..311P