H. J. Staude

The FU Orionis-type spectrum and bipolar outflow of Parsamyan 21

We present CCD images in the red and long-slit spectrograms of the young cometary nebula Parsamyan 21. The spectroscopic and far-infrared properties of its illuminating source are characteristic for an FU Orionis star. The spectrum is of type F5Iab with broad absorption lines and a broad, blueshifted P Cygni profile of Hα, reaching a velocity of −600 km s −1 at the blue edge of its absorption component. The star coincides with a cold IRAS source and is associated with a short bipolar Herbig-Haro outflow oriented along the axis of symmetry of the cometary nebula

RNO 1B — A New FU Ori in Cassiopeia

GN 00.33.9, on the POSS red print a barely visible nebulosity within the dark cloud L 1287, is now a well defined nebula with cometary shape. The star RNO IB, which is deeply embedded in this nebula (A v ~ 9.2 mag), shares all properties defining a FU Ori: it has brightened by at least 3 mag since 1978, its spectral type is F8I-III with a broad, variable and blueshifted P Cygni profile at Hα and broad, double-peaked absorption lines, including Lil 6707. The star coincides within errors with the cold IRAS source 00338+6312 (L[IRAS] = 440 L⊙), which drives a bipolar CO outflow.

Bipolar Nebulae Driven by the Winds of Young Stars

We review the observed properties of young bipolar nebulae. S106 and Cep A are discussed in detail, three recently discovered objects (GN 20.18.3, NS14 and L810) are presented. The characteristics of young bipolar nebulae are then compared to those of young stellar objects (YSOs) observed as cold luminous IRAS sources associated with dense molecular cores and bipolar outflows. It is concluded that they belong to the same early evolutionary stage.

New cometary nebula in Cygnus

CCD images, surface polarimetry, and long-slit spectrograms of a hitherto unknown cometary reflection nebula associated with a dense dust cloud are presented. A bright, compact Herbig-Haro object is embedded in its brightest part. The highly reddened illuminating star of about 3-5 solar masses is located near the apex of the nebula; it emits a collimated bipolar high-velocity flow whose blueshifted component feeds the Herbig-Haro object. The redshifted component can be traced toward the interior of the dark cloud, where the density exceeds 100,000/cu cm. 20 references.

What Causes the Variability of the PV Cep Nebula

We present Gunn r, I, and [SII] images of the variable PV Cep nebula, and longslit spectroscopy taken between 1989 and 1994. The variations in brightness and color are probably due to variable extinction by dust in the wind of PV Cep, implying strong variations of its mass loss rate.

Optical Traces of Two IRAS Sources Driving Bipolar Outflows in the S287 Molecular Cloud

Deep imaging and longslit spectroscopy of two cold, embedded IRAS sources of intermediate luminosity, powering molecular outflows, shows that they are associated with bipolar reflection nebulae. The reflected light consists mainly of H emission with a broad P Cygni profile, as is typical for Herbig Ae/Be stars. The inferred wind velocities are 85 to 120 km s-1.