We have investigated the Hipparcos parallax measurements of stars to estimate the distance to the two nearest star forming clouds to the Sun: MBM12 and MBM20. The Hipparcos observations of previously observed stars suggest that the distances to both of these clouds are not as well constrained as previously thought, although they are consistent with the previous estimates. Therefore, we obtained high resolution spectra of additional Hipparcos stars at intermediate distances and improved the distance estimates to both clouds. The distance to MBM12 is 585 pc 9012 pc and the distance to MBM20 is pc pc. Since there are additional stars that were observed with Hipparcos that are projected near each cloud (though farther off axis than the stars we observed), future spectroscopic observations like those presented here may further refine our distance estimates.
© European Southern Observatory (ESO) 2000
Online publication: June 5, 2000