Spectroscopic Discovery of Brown Dwarf-like Secondary Stars in the Cataclysmic Variables LL Andromedae and EF Eridani

March 2001 • 2001ApJ...550L..57H

Authors • Howell, Steve B. • Ciardi, David R.

Abstract • Infrared spectroscopic observations of LL Andromedae and EF Eridani are presented. Our K-band spectrum of LL And reveals the presence of methane absorption in the secondary star indicating an effective temperature <~1300 K, similar to a ``T''-type methane brown dwarf. The secondary star in EF Eri is seen to be warmer with an effective temperature of ~1650 K and a spectroscopic classification consistent with an L4-5 star. Both secondaries have theoretical mass estimates of 0.04-0.055 M_solar (40-55 M_Jup). Our IR spectroscopic observations of LL And and EF Eri provide the first direct proof of the theoretical prediction that post-period minimum cataclysmic variables contain brown dwarf-like secondary stars.

Links

• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2001ApJ...550L..57H
• PDF https://iopscience.iop.org/article/10.1086/319499/pdf
• PREPRINT http://arxiv.org/abs/astro-ph/0101572
• ELECTR https://doi.org/10.1086%2F319499
• SPIRES http://inspirehep.net/search?p=find+eprint+astro-ph/0101572