Kerzendorf et al .
( 2012 ) recently reported the startling discovery of a metal-poor ( [ { Fe / H } ] \simeq - 1 \pm 0.4 ) A-type star near the center of the Tycho supernova remnant .
We propose two possible explanations .
In the first , Tycho B is a blue straggler , formed from the merger of a close K- or G-type binary system , which was previously in a quadruple system with the binary that produced SN 1572 .
Both binaries were likely brought to tidal contact by Kozai-Lidov oscillations acting in concert with tidal friction .
Analogous progenitor systems may include CzeV343 , VW LMi , and KIC 4247791 .
In the second , Tycho B is the surviving tertiary component of a triple system , which was also likely affected by Kozai-Lidov oscillations .
Rates are briefly discussed .
Problems with each evolutionary scenario are presented .
Finally , a chance alignment between Tycho B and the supernova remnant is not excluded .