Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-05-12
Astronomy and Astrophysics
Astrophysics
8 pages, 3 figures, accepted by A&A
Scientific paper
10.1051/0004-6361:20010690
We present adaptive optics JHKs imaging observations of three main-sequence late B-type stars listed in the Lindroos Catalogue: HD123445, HD127971 and HD129791. Given their spectral types, these stars should not be X-ray emitters. However, they have been detected by ROSAT and their X-ray emission has been attributed to possible unresolved late-type companions. We have carried out near-IR observations with ADONIS at the ESO 3.6m but have not detected any late-type companions close to HD127971 and HD129791. This result leads us to conclude that either (i) they are spectroscopic binaries with unresolved low-mass companions, or (ii) they are intrinsic X-ray emitters. While the former case would be consistent with the reported high multiplicity of early-type (A and B) stars, the latter would yield a revision of stellar activity theories which do not predict X-ray emission from these stars. On the other hand, HD123445 does indeed show visual companions, namely an apparent subarcsecond faint (Ks=10mag) binary system at a projected separation of 5" from the late-B type star. The JHKs magnitudes and colors of the components are consistent with a pair of Pre Main Sequence (PMS) K-type stars at 140 pc, i.e. possible members of the Upper Centaurus Lupus association. In this case the reported X-ray emission can be ascribed to the new binary system. Nevertheless, spectroscopy is required to confirm the possible PMS nature of the pair.
Brandner Wolfgang
Brown Anthony G. A.
Huelamo Nuria
Neuhaeuser Ralph
Zinnecker Hans
No associations
LandOfFree
ADONIS observations of X-ray emitting late B-type stars in Lindroos systems 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 ADONIS observations of X-ray emitting late B-type stars in Lindroos systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and ADONIS observations of X-ray emitting late B-type stars in Lindroos systems will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-299145