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Emission lines in the long-period Cepheid L Carinae

1994; IOP Publishing; Volume: 420; Linguagem: Inglês

10.1086/173570

1538-4357

Erika Böhm‐Vitense, S. G. Love,

Astro and Planetary Science

view Abstract Citations (20) References (15) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Emission Lines in the Long-Period Cepheid L Carinae Bohm-Vitense, Erika ; Love, Stanley G. Abstract For the Cepheid l Carinae, with a pulsation period of 35.5 days, we have studied the emission-line fluxes as a function of pulsational phase in order to find out whether we see chromospheric and transition-layer emission due to an outward-moving shock. All emission lines show a steep increase in flux shortly before maximum light, suggestive of a shock moving through the surface layers. The large ratio of C IV to C II line fluxes shows that these are not transition-layer lines. During maximum light the large ratio of the large ratio of the C IV to C II line fluxes also suggests that we see emission from a shock with velocities greater than 100 km/s such that C IV emission can be excited. With such velocities mass outflow appears possible. The variations seen in the MG II line profiles show that there is an external absorption over a broad velocity band independent of the pulsation phase. We attribute this absorption to a circumstellar 'shell.' This 'shell' appears to be seen also as spatially extended emission in the O I line at 1300 A, which is probably excited by resonance with Ly beta. Publication: The Astrophysical Journal Pub Date: January 1994 DOI: 10.1086/173570 Bibcode: 1994ApJ...420..401B Keywords: Carbon; Cepheid Variables; Emission Spectra; Periodic Variations; Shock Waves; Stellar Envelopes; Magnesium; Oxygen; Spectrum Analysis; Ultraviolet Astronomy; Astrophysics; SHOCK WAVES; STARS: INDIVIDUAL CONSTELLATION NAME: L CARINAE; STARS: VARIABLES: CEPHEIDS; ULTRAVIOLET: STARS full text sources ADS | data products SIMBAD (2) MAST (1) INES (1)