The new nebula in LDN 1415 – A cry from the cradle of a low-luminosity source*
Thüringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany e-mail: email@example.com
2 Ulugh Beg Astronomical Institute, Academy of Science of Uzbekistan, Astronomical str. 33, Tashkent 700051, Uzbekistan
Accepted: 8 November 2006
Aims.A survey for candidate Herbig-Haro objects was performed to search for evidence of star formation in Galactic dark clouds
Methods.For this aim true colour images were created from blue, red, and infrared DSS2 plates and inspected. Follow-up I-band, Hα, and [S ii] CCD imaging as well as long-slit spectroscopy using the Tautenburg 2-m telescope was carried out to verify candidate objects.
Results.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 3.8 mag in recent years.
Conclusions.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 0.9 μm to 60 μm in the low state amounts to 0.13 for an assumed distance of 170 pc. 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 Hα line. L1415-IRS is by far the least luminous member of the sparse sample of FUor and EXor objects.
Key words: stars: formation / stars: low-mass, brown dwarfs / stars: pre-main sequence / stars: variables: general / ISM: Herbig-Haro objects / ISM: jets and outflows
© ESO, 2007