Astronomy and Astrophysics – Astronomy
Scientific paper
Dec 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994lock.reptt....s&link_type=abstract
Final Report Lockheed Missiles and Space Co., Palo Alto, CA.
Astronomy and Astrophysics
Astronomy
Eclipsing Binary Stars, Emission Spectra, Extreme Ultraviolet Radiation, Prototypes, Stellar Coronas, T Tauri Stars, Ultraviolet Astronomy, Ultraviolet Spectra, Continuum Flow, Extreme Ultraviolet Explorer Satellite, High Temperature Plasmas, Light Curve, Ultraviolet Spectroscopy
Scientific paper
This program involves analysis and interpretation of EUVE spectrometer observations of the active stars Algol (beta Per) and 71 Tauri. The EUVE satellite spectrometers observed the prototype eclipsing binary Algol over nearly 1.5 orbital periods. Effective exposure times were 100 ksec and 89 ksec in the short wave (70-180 A) and medium wave (140-370 A) channels. High temperature (up to 20 MK) Fe XVI-XXIV emission lines are clearly detected in the overall spectrum. In addition, a quiescent continuum is present which increases towards shorter wavelengths. Using synthesized spectra of optically thin line and continuum emission folded through the instrumental response, we have examined constraints on the (Fe/H) coronal abundance in Algol. We find that the coronal Fe is underabundant by factors that approximately equal 2-4 relative to solar photospheric values, unless an unreasonably large quantity of coronal plasma at T greater than 30 MK is present in the quiescent spectrum. The latter possibility is, however, inconsistent with available X-ray data. Lightcurves of the high temperature EUV lines compared to line emission at He II 304 A show considerable differences, with much deeper minima present in the He II line during both primary and secondary eclipses. Toward the end of the observation a moderate flare lasting approximately 6 hours was detected in the high temperature Fe emission lines. The 71 Tau observation, for about the same exposure time, revealed only a handful of weak emission lines; however, the strongest lines were also those of Fe XXIII/XX, suggesting a hot coronal plasma. No obvious flaring or other variation was present in the 71 Tau Deep Survey lightcurve.
No associations
LandOfFree
The quiescent and flaring EUV spectrum of Algol and its relationship to other active coronae. EUV spectroscopy of bright hyades coronae: 71 Tauri and Theta 1 Tauri does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The quiescent and flaring EUV spectrum of Algol and its relationship to other active coronae. EUV spectroscopy of bright hyades coronae: 71 Tauri and Theta 1 Tauri, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The quiescent and flaring EUV spectrum of Algol and its relationship to other active coronae. EUV spectroscopy of bright hyades coronae: 71 Tauri and Theta 1 Tauri will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1412104