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The Cosmic Distance Ladder The Cosmic Distance Ladder
The Cosmic Distance LadderThe Cosmic Distance Ladder
Distance Measurements via ParallaxDistance Measurements via Parallax
Hipparcos Satellite Before LaunchHipparcos Satellite Before Launch
GAIA GAIA –– A Planned Future MissionA Planned Future Mission
Estimating the Distance to Estimating the Distance to a Stop Lighta Stop Light
Cepheid Variable StarsCepheid Variable Stars
The PeriodThe Period--Luminosity Relation for Luminosity Relation for Cepheid Variable StarsCepheid Variable Stars
Henrietta Leavitt
HST Observations of Cepheid HST Observations of Cepheid Variable Stars in M100 at ~ 20 MpcVariable Stars in M100 at ~ 20 Mpc
HST key project measured Cepheid distances to ~ 25 galaxies within 25 Mpc.
Distances from Type 1a SupernovaeDistances from Type 1a Supernovae
Mass Discovery of Type 1a SupernovaeMass Discovery of Type 1a Supernovae
Light Curves of Type 1a Light Curves of Type 1a SupernovaeSupernovae
Peak luminosity and subsequent fading are related.
SNAP SNAP –– A Planned Mission toA Planned Mission toMeasure Distances to Type 1a Measure Distances to Type 1a
SupernovaeSupernovae
