Bibcode
Reipurth, B.; Corradi, R. L. M.; Aspin, C.; Schwarz, H. E.
Referencia bibliográfica
Astronomy and Astrophysics, v.319, p.267-273
Fecha de publicación:
3
1997
Revista
Número de citas
74
Número de citas referidas
56
Descripción
Using optical images and spectra of the bipolar nebula M 2-9 we show
that, in addition to the well-known bright inner nebula, the object has
fast, highly collimated outflows reaching a total extent of 115". These
radially opposed and point-symmetric outer lobes are both redshifted,
leading us to model the radiation from them in terms of light reflected
from moving dust, rather than intrinsic emission. Our polarization
images show that the lobes are 60% linearly polarized in a direction
perpendicular to the long axis of M 2-9. This high polarization
indicates optically thin scattering, and lends weight to our dust
scattering model. Use of this model then allows us to determine the
distance to M 2-9 directly from the measured proper motions on images
taken over a period of more than 16 yrs. The physical and geometrical
parameters of the nebula then follow. M 2-9 is at a distance of 650pc,
is 0.4pc long, has a luminosity of 550Lsun_, and its outer
nebula has a dynamical age of 1200yrs, in round numbers. Using the fact
that the central object has been constrained to be of low luminosity but
of a sufficiently high temperature to make the observed OIII, we argue
that the central object of M 2-9 has to contain a compact, hot source,
and is probably a binary.