LOM v1.0atomicLOM v1.01URLhttp://portal.discoverthecosmos.eu/node/187306enThe aim of this exercise focuses on the analysis of narrow band images (as in the case of planetary nebulae) and on the nature of the emission from extended objects. Emission observed in Hα at 6563 A and the forbidden lines of singly ionized sulphur at 6716 and 6731 A may originate from photoionization or from shock heated gas. Their relation can be a useful diagnostic tool.Supernova Remnantsacquire images in the hydrogen emission line Hα and sulphur [SII]Supernova remnants, narrow band filters, forbidden line emission, Balmer line emissiondetermine the [SII]/ Hα ratio and consequentlyLOM v1.0final1.0LOM v1.0author2009-09-28Fotis MavrommatakisLOM v1.0publisher2009-09-28FORTH/ Skinakas ObservatoryenLOM v1.0LOM v1.0creator2009-09-28George PaterakisLOM v1.0validatorLOM v1.0operating systemLOM v1.0ms-windowstext/htmlhttp://portal.discoverthecosmos.eu/node/187306LOM v1.0noLOM v1.0yesLOM v1.0expositivevery lowLOM v1.0difficult2 didactic hoursLOM v1.0exerciseLOM v1.0learnerLOM v1.0higher education25+LOM v1.0DisciplineScienceAstronomy: Supernova remnants