SCIENCE GOALS AND OBJECTIVES: IN THIS PROPOSAL WE WILL STUDY THE HABITABLE ZONES OF ORGANIC-RICH ATMOSPHERES ON PLANETS AROUND DIFFERENT STAR TYPES. THE FEEDBACKS BETWEEN ORGANICS IN THE ATMOSPHERE AND THE CLIMATE AT THE SURFACE ARE COMPLEX: ORGANIC GASEOUS SPECIES ABSORB OUTGOING IR RADIATION AND ACT AS A GREENHOUSE GAS; HOWEVER CONDENSES ORGANIC AEROSOLS ABSORB AND REFLECT INCOMING UV RADIATION AND ACT AS AN ANTI-GREENHOUSE SPECIES. THE PROCESS OF AEROSOL FORMATION IS ITSELF A FUNCTION OF THE PHOTOLYSIS OF THE GASEOUS SPECIES WHICH DEPENDS ON THE AMOUNT AND SPECTRAL DISTRIBUTION OF THE ENERGY FLUX HITTING THE TOP OF THE PLANET'S ATMOSPHERE. WE PROPOSE TO STUDY THE COMPLEX FEEDBACKS THAT RESULT FROM THIS PROCESS AROUND A VARIETY OF STAR TYPES CALCULATE THE NET CLIMATIC EFFECTS OF THE PRESENCE OF THESE ATMOSPHERIC ORGANICS AND ASSESS THE HABITABLE ZONE (HZ) BOUNDARIES FOR WORLDS WITH SUCH ATMOSPHERES. THIS WILL AFFECT THE HZ IN DIFFERENT WAYS FOR PLANETS AROUND DIFFERENT TYPE STARS AND SO WILL ADD NUANCES TO THE CONCEPT OF THE HZ.