The number of low-mass brown dwarfs and even free floating planetary mass objects in young nearby star-forming regions and associations is continuously increasing , offering the possibility to study the low-mass end of the IMF in greater detail .
In this paper , we present six new candidates for ( very ) low-mass objects in the Taurus star-forming region one of which was recently discovered in parallel by .
The underlying data we use is part of a new database from a deep near-infrared survey at the Calar Alto observatory .
The survey is more than four magnitudes deeper than the 2MASS survey and covers currently \sim 1.5 deg ^ { 2 } .
Complementary optical photometry from SDSS were available for roughly 1.0 deg ^ { 2 } .
After selection of the candidates using different color indices , additional photometry from Spitzer/IRAC was included in the analysis .
In greater detail we focus on two very faint objects for which we obtained J -band spectra .
Based on comparison with reference spectra we derive a spectral type of L2 \pm 0.5 for one object , making it the object with the latest spectral type in Taurus known today .
From models we find the effective temperature to be 2080 \pm 140 K and the mass 5-15 Jupiter masses .
For the second source the J -band spectrum does not provide a definite proof of the young , low-mass nature of the object as the expected steep water vapor absorption at 1.33 \mu m is not present in the data .
We discuss the probability that this object might be a background giant or carbon star .
If it were a young Taurus member , however , a comparison to theoretical models suggests that it lies close to or even below the deuterium burning limit ( < 13 M _ { Jup } ) as well .
A first proper motion analysis for both objects shows that they are good candidates for being Taurus members .