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We present the first results from our search for close stellar andsub-stellar companions to young nearby stars on the northern sky. Our infraredimaging observations are obtained with the 3.5 m Calar Alto telescope and theAO system ALFA. With two epoch observations which were separated by about oneyear, we found two co-moving companion candidates, one close to HD 77407 andone close to GJ 577. For the companion candidate near GJ 577, we obtained anoptical spectrum showing spectral type M4.5; this candidate is a bound low-massstellar companion confirmed by both proper motion and spectroscopy. We estimatethe masses for HD 77407 B and GJ 577 B to be ~0.3 to 0.5 Msun and ~0.16 to 0.2Msun, respectively. Compared to Siess al.(2000) models, each of the two pairsappears co-eval with HD 77407 A,B being 10 to 40 Myrs old and GJ 577 A,B beingolder than 100 Myrs. We also took multi-epoch high-resolution spectra of HD77407 to search for sub-stellar companions, but did not find any with 3 Mjup asupper mass (msin(i)) limit (for up to 4 year orbits); however, we detected along-term radial velocity trend in HD 77407 A, consistent with a ~ 0.3 Msuncompanion at ~ 50 AU separation, i.e. the one detected by the imaging. Hence,HD 77407 B is confirmed to be a bound companion to HD 77407 A. We also presentlimits for undetected, but detectable companions using a deep image of HD 77407A and B, also observed with the Keck NIRC2 AO system; any brown dwarfs weredetectable outside of 0.5 arcsec (17 AU at HD 77407), giant planets with massesfrom ~ 6.5 to 12 Mjup were detectable at > 1.5 arcsec.Comment: in pres

HD 77407 and GJ 577: Two new young stellar binaries