The Discovery of Several Probable Runaway Stars in the Cygnus X Region

We report the discovery of three candidate runaway stars in the Cygnus X region identified by bowshocks found in Spitzer Space Telescope mid-IR images. Followup optical spectroscopy from the Wyoming Infrared Observatory 2.3 mtelescope and the WIYN 3.5 m telescope were obtained during 2008 June and July to determine spectral types and radial velocities

of these stars. All three runaway candidates are massive early type stars,

typical of the known runaway stars in the Galaxy. One object, GSC03161-01188 is an 09V with a radial velocity of -17 km/s, similar to the mean radial velocity of the nearby Cygnus OB2 association. Another source, G80.90209+0.98298 has a radial velocity of -12 km/s. HD195299, a known B0.2III star with a high proper motion, has a radial velocity of -16 km/s, again consistent with other massive stars in the vicinity including Cyg OB2 members. The present data are insufficient to allow us to pinpoint the origins of these runaways. Only G80.90209+0.98298 has a bowshock morphology that could be consistent with an origin within Cygnus OB2. Taken together, these results indicate modest radial velocities but potentially large tangential velocities. The number of new runaway stars in

this region is consistent with Cygnus X being a birthplace for new high-velocity stars. We also provide the first radial velocity measurement, -66 km/s, for BD+43 3654, a known runaway star with a mid-infrared bowshock.