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We present Spitzer observations and McDonald Observatory Smith Telescope andAnglo-Australian Telescope high spectral resolution optical observations of 4nearby stars with variable or anomalous optical absorption, likely caused bycircumstellar material. The optical observations of CaII and NaI cover a 2.8year baseline, and extend the long term monitoring of these systems by previousresearchers. In addition, mini-surveys of the local interstellar medium (LISM)around our primary targets provide a reconstruction of the intervening LISMalong the line of sight. We confirm that the anomalous absorption detectedtoward alpha Oph is not due to circumstellar material, but to a smallfilamentary cloud <14.3 pc from the Sun. The three other primary targets, betaCar, HD85905, and HR10 show both short and long term variability, and little ofthe 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 placeupper limits on any possible fractional infrared luminosity, which range fromL_IR/L_star < 2-5 10^-6, for our three disk stars. No stable gas absorptioncomponent centered at the radial velocity of the star is detected for any ofour targets. Based on simple assumptions of the variable gas absorptioncomponent, we estimate limits on the circumstellar gas mass causing thevariable absorption, which range from 0.4-20 10^-8 M_Earth. Thesemultiwavelength observations place strong limits on any possible circumstellardust, while confirming variable circumstellar gas absorption, and therefore areinteresting targets to explore the origins and evolution of variablecircumstellar gas. (abridged)Comment: 65 pages, 16 figures; Accepted for publication in Ap

SpitzerLimits on Dust Emission and Optical Gas Absorption Variability around Nearby Stars with Edge‐on Circumstellar Disk Signatures