A survey for candidate Herbig-Haro objects was performed to search for
evidence of star formation in Galactic dark clouds. For this aim true colour
images were created from blue, red, and infrared DSS2 plates and inspected.
Follow-up I-band, Halpha, and [SII] CCD imaging and long-slit spectroscopy
using the Tautenburg 2-m telescope was carried out to verify candidate objects.
In the case of LDN 1415, the presence of a Herbig-Haro flow could be revealed
which is henceforth named HH 892. In addition, an arcuate nebula was found
which is barely seen on the DSS2 infrared plate (epoch 1996) and not detected
in archival Kiso Schmidt data (epoch 2001). Thus, this nebula must have
brightened by about 3.8mag in recent years.The nebula is associated with IRAS
04376+5413. The 2MASS images show a red counterpart of the IRAS source,
designated as L1415-IRS. Its morphology resembles that of a bipolar young
object. The luminosity of this source integrated from 0.9micron to 60micron in
the low state amounts to 0.13L_sun for an assumed distance of 170pc. Thus it
seems to be a young very-low mass star or it might even be of substellar mass.
The current brightness increase of the nebula is caused by a FUor- or EXor-like
outburst as indicated by the presence of a P Cygni profile of the Halpha line.
L1415-IRS is by far the least luminous member of the sparse sample of FUor and
EXor objects.Comment: 6 pages, 6 figures, accepted by A&