Interferometric Observations of Herbig Ae/Be Stars at 2.73 mm
Session 48 -- Young Stars
Display presentation, Tuesday, 10, 1995, 9:20am - 6:30pm

## [48.14] Interferometric Observations of Herbig Ae/Be Stars at 2.73 mm

J. Di Francesco, P.M. Harvey, N.J. Evans II (The University of Texas at Austin), L.G. Mundy (University of Maryland)

We have observed five star-forming regions at 2.73 mm with the IRAM interferometer, centering on the areas containing at least one Herbig Ae/Be star. In three regions, sources were definitely detected at a level greater than $3\sigma$\/ at positions not coincident with the positions of the Herbig Ae/Be stars. Two other sources were possibly detected at the $3\sigma$\/ level at positions within a beamwidth of the Herbig Ae/Be stars. For the BD+$40^{\circ}4124$ region, emission was detected at neither BD+$40^{\circ}4124$ nor V1686 Cyg. Instead, the emission peaks 1$^{\prime\prime}$ north of V1318 Cyg S, a source recently argued to be the origin of an outflow and water maser by Palla et al. (1994). For the LkH$\alpha$ 198 region, emission peaked at neither LkH$\alpha$ 198, LkH$\alpha$ 198-IR, nor V376 Cas. Instead, it peaks at a position 4$^{\prime\prime}$ north of the source described by Sandell \& Weintraub (1994) as dominating the region at 800 $\mu$\/m. In addition, 2.73 mm emission peaked not at the position of AB Aur, but at a location 7$^{\prime\prime}$ east-southeast of it (P.A. = 105$^{\circ}$\/.) No known source has been detected at this position. This detection, however, is less definite than the previous two. Finally, 2.73 mm emission may have been detected close to both V645 Cyg and MWC 137 (i.e., within 3$^{\prime\prime}$\/.) This result suggests that nearby embedded sources, rather than Herbig Ae/Be stars, have compact regions of dust emission (often attributed to circumstellar disks) around them. This preliminary result underscores the difficulty of assessing putative disk properties with single-dish observations for stars within regions of crowded star formation.