TY - JOUR
T1 - New slowly pulsating B stars in the field of the young open cluster NGC2244 discovered by the MOST photometric satellite
AU - Gruber, D.
AU - Saio, H.
AU - Kuschnig, R.
AU - Fossati, L.
AU - Handler, G.
AU - Zwintz, K.
AU - Weiss, W. W.
AU - Matthews, J. M.
AU - Guenther, D. B.
AU - Moffat, A. F.J.
AU - Rucinski, S. M.
AU - Sasselov, D.
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/2
Y1 - 2012/2
N2 - During two weeks of nearly continuous optical photometry of the young open cluster NGC2244 obtained by the Microvariability and Oscillations of STars (MOST) satellite, we discovered two new slowly pulsating B (SPB) stars, GSC 00154-00785 and GSC 00154-01871. We present frequency analyses of the MOST light curves of these stars, which reveal two oscillation frequencies (0.61 and 0.71 cycled -1) in GSC 00154-00785 and two (0.40 and 0.51 cycled -1) in GSC 00154-01871. These frequency ranges are consistent with g modes of ℓ≤ 2 excited in models of main-sequence or pre-main-sequence (PMS) stars of masses 4.5-5M ⊙ and solar composition (X, Z) = (0.7, 0.02). Published proper motion measurements and radial velocities are insufficient to establish unambiguously cluster membership for these two stars. However, the PMS models which fit best their eigenspectra have ages consistent with NGC2244. If cluster membership can be confirmed, these would be the first known PMS SPB stars, and would open a new window on testing asteroseismically the interior structures of PMS stars.
AB - During two weeks of nearly continuous optical photometry of the young open cluster NGC2244 obtained by the Microvariability and Oscillations of STars (MOST) satellite, we discovered two new slowly pulsating B (SPB) stars, GSC 00154-00785 and GSC 00154-01871. We present frequency analyses of the MOST light curves of these stars, which reveal two oscillation frequencies (0.61 and 0.71 cycled -1) in GSC 00154-00785 and two (0.40 and 0.51 cycled -1) in GSC 00154-01871. These frequency ranges are consistent with g modes of ℓ≤ 2 excited in models of main-sequence or pre-main-sequence (PMS) stars of masses 4.5-5M ⊙ and solar composition (X, Z) = (0.7, 0.02). Published proper motion measurements and radial velocities are insufficient to establish unambiguously cluster membership for these two stars. However, the PMS models which fit best their eigenspectra have ages consistent with NGC2244. If cluster membership can be confirmed, these would be the first known PMS SPB stars, and would open a new window on testing asteroseismically the interior structures of PMS stars.
KW - Open clusters and associations: individual: NGC2244
KW - Stars: early-type
KW - Stars: individual: GSC 00154-00785
KW - Stars: individual: GSC 00154-01871
KW - Stars: oscillations
KW - Stars: pre-main-sequence
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U2 - 10.1111/j.1365-2966.2011.20033.x
DO - 10.1111/j.1365-2966.2011.20033.x
M3 - Article
AN - SCOPUS:84856208913
VL - 420
SP - 291
EP - 298
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 1
ER -