Bibcode
Zhang, Z. H.; Pinfield, D. J.; Day-Jones, A. C.; Burningham, B.; Jones, H. R. A.
Bibliographical reference
Research, Science and Technology of Brown Dwarfs and Exoplanets: Proceedings of an International Conference held in Shangai on Occasion of a Total Eclipse of the Sun, Shangai, China, Edited by E.L. Martin; J. Ge; W. Lin; EPJ Web of Conferences, Volume 16, id.06014
Advertised on:
7
2011
Citations
1
Refereed citations
1
Description
Ultra-cool dwarfs as wide companions to subgiants, giants, white dwarfs
and main sequence stars can be very good benchmark objects, for which we
can infer physical properties with minimal reference to theoretical
models, through association with the primary stars. We have searched for
benchmark ultra-cool dwarfs in widely separated binary systems using
SDSS, UKIDSS, and 2MASS. We then estimate spectral types using SDSS
spectroscopy and multi-band colors, place constraints on distance, and
perform proper motions calculations for all candidates which have
sufficient epoch baseline coverage. Analysis of the proper motion and
distance constraints show that eight of our ultra-cool dwarfs are
members of widely separated binary systems. Another L3.5 dwarf, SDSS
0832, is shown to be a companion to the bright K3 giant η Cancri.
Such primaries can provide age and metallicity constraints for any
companion objects, yielding excellent benchmark objects. This is the
first wide ultra-cool dwarf + giant binary system identified.