Search and characterization of T-type planetary mass candidates in the σ Orionis cluster

Content Provider	Scilit
Author	Ramírez, Karla Peña Osorio, Maria R. Zapatero Béjar, Victor J. S.
Copyright Year	2010
Description	We present new photometric and astrometric data available for S Ori 70 and 73, the two T-type planetary-mass member candidates in the σ Orionis cluster (~3 ± 2 Myr, d~360 pc). S Ori 70 (J ~ 19.9 mag) has a spectral type of T5.5 ± 1.0 measured from published near-infrared spectra, while no spectroscopic data are available for S Ori 73 (J ~ 21 mag). We estimate the spectral type of S Ori 73 by using J, H, and $CH_{4off}$ $(λ_{c}$=1.575 μm, Δλ=0.112 μm) photometry and comparing the $H-CH_{4off}$ index of S Ori 73 with the colors of field stars and brown dwarfs of spectral types in the range F to late T. The locations of S Ori 70 and 73 in the J-H vs $H-CH_{4off}$ color-color diagram are consistent with spectral types T8 ± 1 and T4 ± 1, respectively. Proper motion measurements of the two sources are larger than the motion of the central σ Ori star, making their cluster membership somehow uncertain.
Related Links	https://www.cambridge.org/core/services/aop-cambridge-core/content/view/46325584E8283542B4B5ECFEE17DCBBE/S1743921311020928a.pdf/div-class-title-search-and-characterization-of-t-type-planetary-mass-candidates-in-the-orionis-cluster-div.pdf
Ending Page	490
Page Count	2
Starting Page	489
ISSN	17439213
e-ISSN	17439221
DOI	10.1017/s1743921311020928
Journal	Proceedings of the International Astronomical Union
Issue Number	S276
Volume Number	6
Language	English
Publisher	Cambridge University Press (CUP)
Publisher Date	2010-10-01
Access Restriction	Open
Subject Keyword	Proceedings of the International Astronomical Union Astronomy and Astrophysics Stars Brown Dwarfs Planetary Systems Individual (σ Orionis)
Content Type	Text
Resource Type	Article
Subject	Astronomy and Astrophysics Space and Planetary Science