  We present Spitzer observations and McDonald Observatory Smith Telescope and
Anglo-Australian Telescope high spectral resolution optical observations of 4
nearby stars with variable or anomalous optical absorption, likely caused by
circumstellar material. The optical observations of CaII and NaI cover a 2.8
year baseline, and extend the long term monitoring of these systems by previous
researchers. In addition, mini-surveys of the local interstellar medium (LISM)
around our primary targets provide a reconstruction of the intervening LISM
along the line of sight. We confirm that the anomalous absorption detected
toward alpha Oph is not due to circumstellar material, but to a small
filamentary cloud <14.3 pc from the Sun. The three other primary targets, beta
Car, HD85905, and HR10 show both short and long term variability, and little of
the observed absorption can be attributed to the LISM along the line of sight.
The Spitzer observations did not detect infrared excesses. We are able to place
upper limits on any possible fractional infrared luminosity, which range from
L_IR/L_star < 2-5 10^-6, for our three disk stars. No stable gas absorption
component centered at the radial velocity of the star is detected for any of
our targets. Based on simple assumptions of the variable gas absorption
component, we estimate limits on the circumstellar gas mass causing the
variable absorption, which range from 0.4-20 10^-8 M_Earth. These
multiwavelength observations place strong limits on any possible circumstellar
dust, while confirming variable circumstellar gas absorption, and therefore are
interesting targets to explore the origins and evolution of variable
circumstellar gas. (abridged)
