The V380 Ori NE bipolar outflow was imaged in the SiO and CO J = 1 \rightarrow 0 lines , and dense cores in L1641 were observed in the 2.0–0.89 mm continuum .
The highly collimated SiO jet shows point-symmetric oscillation patterns in both position and velocity , which suggests that the jet axis is precessing and the driving source may belong to a non-coplanar binary system .
By considering the position and velocity variabilities together , accurate jet parameters were derived .
The protostellar system is viewed nearly edge-on , and the jet has a flow speed of \sim 35 km s ^ { -1 } and a precession period of \sim 1600 years .
The CO outflow length gives a dynamical timescale of \sim 6300 years , and the protostar must be extremely young .
The inferred binary separation of 6–70 au implies that this protobinary system may have been formed through the disk instability process .
The continuum spectra of L1641 dense cores indicate that the emission comes from dust , and the fits with modified blackbody functions give emissivity power indices of \beta = 0.3–2.2 .
The emissivity index shows a positive correlation with the molecular line width , but no strong correlation with bolometric luminosity or temperature .
V380 Ori NE has a particularly low value of \beta = 0.3 , which tentatively suggests the presence of millimeter-sized dust grains .
Because the dust growth takes millions of years , much longer than the protostellar age , this core may have produced large grains in the starless core stage .
HH 34 MMS and HH 147 MMS also have low emissivity indices .