Envisioning the Distance Ladder in the Era of the Habitable Worlds Observatory

2025/07/02 by Gagandeep Anand, Meredith Durbin, Anand, Gagandeep +7 · 2 voices · 1 citation
#astro-ph.CO #astro-ph.IM

paper · pdf · doi:10.48550/arxiv.2507.02056

Abstract

The current state-of-the-art cosmic distance ladder requires three rungs--geometric distances, primary indicators, and Type Ia Supernovae--to achieve a 1% measurement of the Hubble constant H₀. The Habitable Worlds Observatory will have the sensitivity and resolution to reduce this to a two-step measurement, eliminating the third rung entirely and reaching into the Hubble flow with stellar distance indicators such as Cepheid variables and the tip of the red giant branch alone. We discuss the requirements for a program to measure H₀ to 1% with HWO here, including telescope and instrument design considerations. We also comment on the potential of HWO to measure distances to low-mass dwarf galaxies via their RR Lyrae stars.

Cited by

• 1.8 per cent measurement of H₀ from Cepheids alone

Discussions

• in the #arXiv Envisioning the Distance Ladder in the Era of the Habitable Worlds Observatory by Gagandeep Anand @styrofoamplates.bsky.social and co-authors arxiv.org/abs/2507.02056 #HWO #Cosmology 🧪 [bsky, 22 points, 1 comments]
• in the # arXiv Envisioning the Distance Ladder in the Era of the Habitable Worlds Observatory by Gagandeep Anand and co-authors https:// arxiv.org/abs/2507.02056 # HWO # Cosmology # HabitableWorldsObs [mastodon, 0 points, 0 comments]

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