PEZZUTO, StefanoStefanoPEZZUTOELIA, Davide QuintinoDavide QuintinoELIASCHISANO, EUGENIOEUGENIOSCHISANOStrafella, F.F.StrafellaDi Francesco, J.J.Di FrancescoSadavoy, S.S.SadavoyAndré, P.P.AndréBENEDETTINI, MilenaMilenaBENEDETTINIBernard, J. P.J. P.BernardDI GIORGIO, Anna MariaAnna MariaDI GIORGIOFacchini, A.A.FacchiniHennemann, M.M.HennemannHill, T.T.HillKönyves, V.V.KönyvesMOLINARI, SergioSergioMOLINARIMotte, F.F.MotteNguyen-Luong, Q.Q.Nguyen-LuongPeretto, N.N.PerettoPestalozzi, M.M.PestalozziPolychroni, D.D.PolychroniRYGL, Kazi Lucie JessicaKazi Lucie JessicaRYGLSaraceno, P.P.SaracenoSchneider, N.N.SchneiderSPINOGLIO, Luigi Giuseppe MariaLuigi Giuseppe MariaSPINOGLIOTESTI, LeonardoLeonardoTESTIWard-Thompson, D.D.Ward-ThompsonWhite, G. J.G. J.White2023-01-232023-01-2320120004-6361http://hdl.handle.net/20.500.12386/32978We report far-infrared Herschel observations obtained between 70 μm and 500 μm of two star-forming dusty condensations, <ASTROBJ>[HKM99] B1-bS</ASTROBJ> and <ASTROBJ>[HKM99] B1-bN</ASTROBJ>, in the <ASTROBJ>B1</ASTROBJ> region of the Perseus star-forming cloud. In the western part of the Perseus cloud, <ASTROBJ>B1-bS</ASTROBJ> is the only source detected in all six PACS and SPIRE photometric bands, but it is not visible in the Spitzer map at 24 μm. B1-bN is clearly detected between 100 μm and 250 μm. We have fitted the spectral energy distributions of these sources to derive their physical properties, and find that a simple greybody model fails to reproduce the observed spectral energy distributions. At least a two-component model is required, consisting of a central source surrounded by a dusty envelope. The properties derived from the fit, however, suggest that the central source is not a Class 0 object. We then conclude that while B1-bS and B1-bN appear to be more evolved than a pre-stellar core, the best-fit models suggest that their central objects are younger than a Class 0 source. Hence, they may be good candidates to be examples of the first hydrostatic core phase. The projected distance between B1-bS and B1-bN is a few Jeans lengths. If their physical separation is close to this value, this pair would allow studying the mutual interactions between two forming stars at a very early stage of their evolution. <P />Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendices are available in electronic form at <A href="http://www.aanda.org">http://www.aanda.org</A>STAMPAenArticle10.1051/0004-6361/2012195012-s2.0-84867882870https://www.aanda.org/articles/aa/full_html/2012/11/aa19501-12/aa19501-12.htmlhttp://arxiv.org/abs/1209.5290v12012A&A...547A..54PFIS/05 - ASTRONOMIA E ASTROFISICA