Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-02-13
Astronomy and Astrophysics
Astrophysics
8 pages, 11 figures. Accepted for publication in MNRAS
Scientific paper
10.1111/j.1365-2966.2008.13105.x
Pulsation in beta Cep and SPB stars are driven by the kappa mechanism which depends critically on the metallicity. It has therefore been suggested that beta Cep and SPB stars should be rare in the Magellanic Clouds which have lower metallicities than the solar neighborhood. To test this prediction we have observed the open SMC cluster NGC 371 for 12 nights in order to search for beta Cep and SPB stars. Surprisingly, we find 29 short-period B-type variables in the upper part of the main sequence, many of which are probably SPB stars. This result indicates that pulsation is still driven by the kappa mechanism even in low metallicity environments. All the identified variables have periods longer than the fundamental radial period which means that they cannot be beta Cep stars. Within an amplitude detection limit of 5 mmag no stars in the top of the HR-diagram show variability with periods shorter than the fundamental radial period. So if beta Cep stars are present in the cluster they oscillate with amplitudes below 5 mmag, which is significantly lower than the mean amplitude of beta Cep stars in the Galaxy. We see evidence that multimode pulsation is more common in the upper part of the main sequence than in the lower. We have also identified 5 eclipsing binaries and 3 periodic pulsating Be stars in the cluster field.
Arentoft Torben
Coutures Ch.
Dogan Gülnur
Glowienka Lars
Grundahl Frank
No associations
LandOfFree
SPB stars in the open SMC cluster NGC 371 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 SPB stars in the open SMC cluster NGC 371, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and SPB stars in the open SMC cluster NGC 371 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-676528