X-ray variability of Pleiades late-type stars as observed with the ROSAT-PSPC

Details X-ray variability of Pleiades late-type stars as observed with the ROSAT-PSPC X-ray variability of Pleiades late-type stars as observed with the ROSAT-PSPC

Aug 2003

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003a%26a...406..629m&link_type=abstract

Astronomy and Astrophysics, v.406, p.629-638 (2003)

Astronomy and Astrophysics

Astrophysics

16

Open Clusters And Associations: Individual: Pleiades, Stars: Coronae, Stars: Late-Type, Stars: Rotation, X-Ray: Stars

Scientific paper

We present a comprehensive analysis of X-ray variability of the late-type (dF7-dM) Pleiades stars, detected in all ROSAT-PSPC observations; X-ray variations on short (hours) and medium (months) time scales have been explored. We have grouped the stars in two samples: 89 observations of 42 distinct dF7-dK2 stars and 108 observations of 61 dK3-dM stars. The Kolmogorov-Smirnov test applied on all X-ray photon time series show that the percentage of cases of significant variability is quite similar on both samples, suggesting that the presence of variability does not depend on mass for the time scales and mass range explored. The comparison between the Time X-ray Amplitude Distribution functions (XAD) of the set of dF7-dK2 and of the dK3-dM show that, on short time scales, dK3-dM stars show larger variations than dF7-dK2. A subsample of eleven dF7-dK2 and eleven dK3-dM Pleiades stars allows the study of variability on longer time scales: we found that variability on medium - long time scales is relatively more common among dF7-dK2 stars than among dK3-dM ones. For both dF7-dK2 Pleiades stars and dF7-dK2 field stars, the variability on short time scales depends on Lx while this dependence has not been observed among dK3-dM stars. It may be that the variability among dK3-dM stars is dominated by flares that have a similar luminosity distribution for stars of different Lx, while flaring distribution in dF7-dK2 stars may depend on X-ray luminosity. The lowest mass stars show significant rapid variability (flares?) and no evidence of rotation modulation or cycles. On the contrary, dF7-dK2 Pleiades stars show both rapid variability and variations on longer time scales, likely associated with rotational modulation or cycles.

Affiliated with

Also associated with

No associations

Rating

X-ray variability of Pleiades late-type stars as observed with the ROSAT-PSPC 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 X-ray variability of Pleiades late-type stars as observed with the ROSAT-PSPC, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and X-ray variability of Pleiades late-type stars as observed with the ROSAT-PSPC will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1662717