We have used the Atacama Pathfinder Experiment 12 m telescope to detect circumstellar CO emission from MP Mus ( K1 IVe ) , a nearby ( D \sim 100 pc ) , actively accreting , \sim 7 Myr-old pre-main sequence ( pre-MS ) star .
The CO emission line profile measured for MP Mus is indicative of an orbiting disk with radius \sim 120 AU , assuming the central star mass is 1.2 M _ { \odot } and the disk inclination is i \sim 30 ^ { \circ } , and the inferred disk molecular gas mass is \sim 3 M _ { \earth } .
MP Mus thereby joins TW Hya and V4046 Sgr as the only late-type ( low-mass ) , pre-MS star systems within \sim 100 pc of Earth that are known to retain orbiting , molecular disks .
We also report the nondetection ( with the Institut de Radio Astronomie Millimetrique 30 m telescope ) of CO emission from another ten nearby ( D \stackrel { < } { \sim } 100 pc ) , dusty , young ( age \sim 10 - 100 Myr ) field stars of spectral type A–G .
We discuss the implications of these results for the timescales for stellar and Jovian planet accretion from , and dissipation of , molecular disks around young stars .