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Paper: Medium-term Variability in Emission from the Orion Nebula
Volume: 390, Pathways Through an Eclectic Universe
Page: 106
Authors: Beckman, J.E.; Gutiérrez, L.; Giammanco, C.
Abstract: Measuring the surface brightness changes in HST images in Hα and [OIII]5007Å taken with a time interval of 6.84 yr, we show how to detect separately the changes due to density variations and those due to temperature variations. Following O’Dell et al., we used the brightness changes to show and measure proper motions in streams and fronts at up to 140 kms−1. The strongest density variations coincide with the proper motions, while in quiescent zones we can detect mean temperature variations of tens of degrees along the line of sight in the time interval between the observations.
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