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The evolution of stellar coronae: initial results from a rosat pspc observation of ic 2391
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Patten, Brian M. Simon, Theodore |
| Copyright Year | 1993 |
| Description | A 23 ks ROSAT PSPC image of the young star cluster, IC 2391, reveals 76 soft x-ray sources with L(sub x)(0.2-2.0 keV) greater than or equal to 2 x 10(exp 28) ergs/s in the direction of the cluster center. Nineteen of these sources are associated with known cluster members. We find that x-ray emission from the IC 2391 B stars deviates widely from the L(sub x)/L(sub bol) = 10(exp -7) relation based on Einstein observations of O and early B stars. Instead, we observe a wide range in L(sub x) with an order of magnitude spread at any given mass and no apparent dependence on spectral type. A comparison of the spread of L(sub x) as a function of B-V for low-mass stars between IC 2391 and the much older Hyades cluster shows that despite the factor of approx. 10 difference in their ages, these two clusters exhibit very similar dispersions in levels of stellar activity. We conclude that the low-mass stars in IC 2391 have arrived on the ZAMS with a wide range of coronal activity levels, from very strong to very weak, and that existing empirical activity-age scaling laws therefore cannot be valid. |
| File Size | 385935 |
| Page Count | 6 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19960017613 |
| Archival Resource Key | ark:/13960/t4hn0535x |
| Language | English |
| Publisher Date | 1993-07-14 |
| Access Restriction | Open |
| Subject Keyword | Astronomy Rosat Mission B Stars O Stars Main Sequence Stars Stellar Evolution Open Clusters Stellar Coronas Stellar Luminosity X Rays Stellar Mass Emission Spectra Sky Surveys Astronomy Stellar Activity X Ray Sources Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
