2003A&A...400..671R

Query : 2003A&A...400..671R

2003A&A...400..671R - Astronomy and Astrophysics, volume 400671-678 (2003/3-3)

Chandra-LETGS X-ray observation of α Centauri: A nearby (G2V + K1V) binary system.

RAASSEN A.J.J., NESS J.-U., MEWE R., VAN DER MEER R.L.J., BURWITZ V. and KAASTRA J.S.

Abstract (from CDS):

A Chandra LETGS X-ray observation of α Centauri with an exposure time of 81.5ks is presented with the two components (K1V and G2V) spectrally resolved for the first time. We use the emission lines from the individual spectra to determine plasma temperatures and find similar temperatures as for the Sun with higher temperatures for the K1V star than for the G2V star. Global fitting techniques are used in order to construct an emission measure distribution for each star and we find emission measure distributions consistent with what is found from the line ratios. A two-temperature model is used in order to derive abundances normalized to iron and relative to solar photosheric values. For both stars we find a FIP effect with a slight but not significant tendency of a stronger FIP effect for the K1V component.

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Journal keyword(s): stars: individual: α Centauri - stars: coronae - stars: late-type - stars: activity - X-rays: stars

Simbad objects: 3

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Number of rows : 3
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026 		#notes
1 * alf Cen B PM* 14 39 35.06311 -60 50 15.0992 2.89 2.21 1.33     K1V 1092 2
2 * alf Cen A SB* 14 39 36.49400 -60 50 02.3737 0.96 0.72 0.01     G2V 1352 1
3 * alf Cen ** 14 39 36.50 -60 50 02.3   0.4 -0.1     G2V+K1V 1031 0

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