other query modes : |
Identifier query |
Coordinate query |
Criteria query |
Reference query |
Basic query |
Script submission |
TAP |
Output options |
Object types |
Help |
1998ApJ...509..761S - Astrophys. J., 509, 761-767 (1998/December-3)
ASCA observations of the T Tauri star SU Aurigae and the surrounding L1517 dark cloud.
SKINNER S.L. and WALTER F.M.
Abstract (from CDS):
Strong X-ray emission was detected from SU Aur (Lx = 1030.9 ergs s–1) as well as weaker emission from five other pre-main-sequence stars. Although no large-amplitude flares were detected, the X-ray emission of SU Aur showed clear variability in the form of a slow decline in count rate during the 1.3 day observation.
We provide the first direct comparison of the coronal differential emission measure (DEM) distribution of a classical T Tauri star with that of a young main-sequence star of similar spectral type. The DEM distributions of SU Aur (G2; age 3 Myr) and the young solar-like star EK Draconis (G0 V; age 70 Myr) are qualitatively similar, with both showing a bimodal temperature distribution characterized by a cool plasma component peaking at ∼8-9 MK and a hot component peaking at ∼20-21 MK. However, there is a striking difference in the relative proportion of plasma at high temperatures in the two stars, with hot plasma (≥20 MK) accounting for ~80% of the volume emission measure of SU Aur, compared to only ~40% in EK Dra.
These results provide new insight into the changes that will occur in the corona of a T Tauri star as it descends onto the main sequence. A sharp decline in the fraction of coronal plasma at flarelike temperatures will occur during the late-T Tauri and post-T Tauri phases, and other recent X-ray studies have shown that this decline will continue after the young solar-like star reaches the main sequence.
Abstract Copyright: ∼
Journal keyword(s): ISM: individual (L1517) - Stars: Coronae - stars: individual (HD 282624) - stars: individual ( SU Aur) - Stars: Pre-Main-Sequence - X-Rays: Stars
Nomenclature: Table 2: [SW98] N (Nos 1-8).
Simbad objects: 15
To bookmark this query, right click on this link: simbad:1998ApJ...509..761S and select 'bookmark this link' or equivalent in the popup menu