TY - JOUR

T1 - SIMULTANEOUS MONITORING OF THE PHOTOMETRIC AND POLARIMETRIC ACTIVITY OF THE YOUNG STAR PV Cep IN THE OPTICAL/NEAR-INFRARED BANDS

AU - Lorenzetti, D.

AU - Giannini, T.

AU - Larionov, V. M.

AU - Arkharov, A. A.

AU - Antoniucci, S.

AU - Di Paola, A.

AU - Konstantinova, T. S.

AU - Kopatskaya, E. N.

AU - Causi, G. Li

AU - Nisini, B.

PY - 2011/5/10

Y1 - 2011/5/10

N2 - We present the results of a simultaneous monitoring, lasting more than two years, of the optical and near-infrared photometric and polarimetric activity of the variable protostar PV Cep. During the monitoring period, an outburst with declining phase (Delta J approximate to 3 mag) lasting about 120 days occurred in all the photometric bands. A time lag of similar to 30 days between optical and infrared light curves has been measured and interpreted in the framework of an accretion event. This latter is directly recognizable in the significant variations of the near-infrared colors, which appear bluer in the outburst phase, when the star dominates the emission, and redder in the declining phase, when the disk emission prevails. All the observational data have been combined to derive a coherent picture of the complex morphology of the whole PV Cep system that is composed of, in addition to the star and the accretion disk, a variable bi-conical nebula. The mutual interaction between all these components is the cause of the high value of the polarization (approximate to 20%) and of its fluctuations. The observational data concur to indicate that PV Cep is not a genuine EXor star, but rather a more complex object; moreover, the case of PV Cep leads to arguments about the classification of other recently discovered young sources in outburst that have been considered, perhaps oversimplifying, as EXor.

AB - We present the results of a simultaneous monitoring, lasting more than two years, of the optical and near-infrared photometric and polarimetric activity of the variable protostar PV Cep. During the monitoring period, an outburst with declining phase (Delta J approximate to 3 mag) lasting about 120 days occurred in all the photometric bands. A time lag of similar to 30 days between optical and infrared light curves has been measured and interpreted in the framework of an accretion event. This latter is directly recognizable in the significant variations of the near-infrared colors, which appear bluer in the outburst phase, when the star dominates the emission, and redder in the declining phase, when the disk emission prevails. All the observational data have been combined to derive a coherent picture of the complex morphology of the whole PV Cep system that is composed of, in addition to the star and the accretion disk, a variable bi-conical nebula. The mutual interaction between all these components is the cause of the high value of the polarization (approximate to 20%) and of its fluctuations. The observational data concur to indicate that PV Cep is not a genuine EXor star, but rather a more complex object; moreover, the case of PV Cep leads to arguments about the classification of other recently discovered young sources in outburst that have been considered, perhaps oversimplifying, as EXor.

KW - infrared: stars

KW - ISM: jets and outflows

KW - stars: individual (PV Cep)

KW - stars: pre-main sequence

KW - stars: protostars

KW - stars: variables: T Tauri, Herbig Ae/Be

KW - T-TAURI STARS

KW - STELLAR OBJECTS

KW - POLARIZATION OBSERVATIONS

KW - MOLECULAR CLOUDS

KW - IRAS SOURCES

KW - NEBULA

KW - VARIABILITY

KW - EVOLUTION

KW - DISK

KW - EXTINCTION

U2 - 10.1088/0004-637X/732/2/69

DO - 10.1088/0004-637X/732/2/69

M3 - статья

VL - 732

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

M1 - 69

ER -