2001/04/16 by M. A. Guerrero, Martin A. Guerrero, You‐Hua Chu +7 · 4 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/320509
5 pages, 3 figures, accepted for publication in the ApJL
arxiv created 2001/04/16 · openalex publication_date 2001/05/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Recent Chandra ACIS-S observations have detected a point source at the central star of NGC 6543 and confirmed the point-source nature of the hard X-ray emission from NGC 7293. The X-ray spectra of both sources peak between 0.5 and 1.0 keV and show line features indicating a thin plasma at temperatures of a few times 10 6 K. Their X-ray luminosities are 10 30 and 3 × 10 29 ergs s -1 , respectively. We have considered four different mechanisms to explain the nature of these sources. The X-ray emission from the central star of NGC 6543 may originate from the coronal activity of an undetected companion star or from shocks in its fast stellar wind, while the hard X-ray emission from NGC 7293 might be ascribed to an undetected dMe companion. Follow-up observations are needed to determine the existence and natures of these stellar companions.