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Periodic modulation of the atmosphere of alpha orionis
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Baliunas, S. L. Dupree, A. K. Nassiopoulos, G. E. Guinan, E. F. Sonneborn, G. Hartmann, L. |
| Copyright Year | 1988 |
| Description | Alpha Orionis (Betelgeuse; M2 Iab) was monitored with IUE since 1984. Discovery of a 420-day periodic modulation of the flux in the optical and ultraviolet continua, and in the Mg II h and k line emission cores suggests that periodic photospheric pulsations were present from 1984 to 1986. This behavior continues through 1987. However, the general flux level of the ultraviolet continuum and the Mg II lines is decreasing, and the amplitude of the variation may be reduced. These decreases may be the emerging signature of an additional longer period. The density sensitive C II diagnostic, 2325.4/2328.1, indicates the chromospheric densities range between log N(sub e) (cm-3) = 8.7 and 9.5, but periodicities are not evident. |
| File Size | 229940 |
| Page Count | 4 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19890001385 |
| Archival Resource Key | ark:/13960/t1qg3m44q |
| Language | English |
| Publisher Date | 1988-06-01 |
| Access Restriction | Open |
| Subject Keyword | Astronomy Stellar Spectra Stellar Atmospheres Stellar Mass Ejection Spaceborne Astronomy Ultraviolet Spectra Iue Supergiant Stars Periodic Variations Ultraviolet Astronomy Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
