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# NGC 146: a young open cluster with a Herbig Be star and intermediate mass pre-main sequence stars

 dc.contributor.author Subramaniam, A dc.contributor.author Sahu, D. K dc.contributor.author Sagar, R dc.contributor.author Vijitha, P dc.date.accessioned 2007-06-19T06:14:14Z dc.date.available 2007-06-19T06:14:14Z dc.date.issued 2005-09 dc.identifier.citation Astronomy & Astrophysics, Vol. 440, pp. 511 - 522 en dc.identifier.uri http://hdl.handle.net/2248/1662 dc.description.abstract We present UBV CCD photometry and low-resolution spectra of stars in the field of the young open cluster NGC 146. UBV photometry of 434 stars were used to estimate the E(B-V) reddening of 0.55 $\pm$ 0.04 mag and BV photometry of 976 stars were used to estimate a distance modulus of (m-M)0 = 12.7 $\pm$ 0.2 mag, corresponding to a distance of 3470 +335-305 pc. We estimated 10-16 Myr as the turn-off age for the upper main sequence of the cluster using isochrones and synthetic colour magnitude diagrams. We identified two B type stars with H$_\alpha$ in emission and located on the MS using slit-less spectra. A higher resolution spectrum of the brighter Be star indicated the presence of a number of emission lines, with some lines showing the signature of gas infall. This star was found to be located in the region of Herbig Ae/Be stars in the (J-H) vs. (H-K) colour-colour diagram. Thus, we identify this star as a Herbig Be star. On the other hand, 54 stars were found to show near infrared excess, of which 17 were found to be located in the region of Herbig Ae/Be stars and 18 stars were found to be located in the region of Be stars in the NIR colour-colour diagram. Thus NGC 146 is a young cluster with a large number of intermediate mass pre-main sequence stars. The turn-on age of the cluster is found to be ~3 Myr. Though NGC 146 shows an older turn off, the bulk of stars in this cluster seems to belong to the younger population of 3 Myr. en dc.format.extent 748935 bytes dc.format.mimetype application/pdf dc.language.iso en en dc.publisher EDP Sciences en dc.relation.uri http://arxiv.org/abs/astro-ph/0505314 en dc.relation.uri http://dx.doi.org/10.1051/0004-6361:20052683 en dc.subject Galaxy: open cluster and associations en dc.subject individual: NGC 146 -- stars: emission-line en dc.subject Be -- stars: Hertzsprung-Russell (HR) and C-M diagrams -- stars en dc.title NGC 146: a young open cluster with a Herbig Be star and intermediate mass pre-main sequence stars en dc.type Article en
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