Poster abstract
Characterization of T-type planetary mass objects candidates in the $\sigma$ Orionis cluster
Abstract
There are only two T-type planetary mass objects candidates in the $\sigma$ Orionis cluster: S Ori 70 (S Ori J053810.1 -023626) and S Ori 73 (S Ori J053814.4-024511). S Ori 70 has a confirmed spectral type T5.5 while S Ori 73 has not any confirming spectra to date.
We intend to estimate the spectral type of S Ori 73 using $JHCH_{4{\scriptsize {\textnormal{off}}}}$ photometry from HAWK-I/VLT. This is the first attempt to provide a spectral type in the case of S Ori 73.
We compare the $H$-$CH_{4{\scriptsize {\textnormal{off}}}}$ color from S Ori 70 and S Ori 73, with $H$-$CH_{4{\scriptsize {\textnormal{off}}}}$ color from a wide spectral range objects, from F type stars to late T field dwarfs. Methane nature of S Ori 73 is confirmed. The locations of S Ori 70 and 73 in the $J$-$H$ vs. $H$-$CH_{4{\scriptsize {\textnormal{off}}}}$ color-color diagram are consistent with T8 and T4 spectral types respectively.
We intend to estimate the spectral type of S Ori 73 using $JHCH_{4{\scriptsize {\textnormal{off}}}}$ photometry from HAWK-I/VLT. This is the first attempt to provide a spectral type in the case of S Ori 73.
We compare the $H$-$CH_{4{\scriptsize {\textnormal{off}}}}$ color from S Ori 70 and S Ori 73, with $H$-$CH_{4{\scriptsize {\textnormal{off}}}}$ color from a wide spectral range objects, from F type stars to late T field dwarfs. Methane nature of S Ori 73 is confirmed. The locations of S Ori 70 and 73 in the $J$-$H$ vs. $H$-$CH_{4{\scriptsize {\textnormal{off}}}}$ color-color diagram are consistent with T8 and T4 spectral types respectively.