Tag

Cepheid Variables

All articles tagged with #cepheid variables

science2 months ago•4 min saved

Unassuming Tiny Star Revolutionizes Cosmic Understanding

A tiny star in the Andromeda galaxy, V1, played a crucial role in transforming our understanding of the universe by helping establish that Andromeda is a separate galaxy and by contributing to the development of the cosmic distance ladder, which has enabled measurements of the universe's expansion and age. This discovery, along with subsequent observations, has led to insights about the universe's accelerating expansion driven by dark energy, and ongoing efforts aim to resolve discrepancies in the Hubble constant.

via Earth.com|

#astronomy #cepheid-variables #cosmic-expansion

science7 months ago•5 min saved

New Map Unveils Clumped 'Flocculent' Structure of Milky Way's Atomic Hydrogen

A new map of the Milky Way's outer gas disk has been created using a novel 'pattern matching' technique that pairs young stars, specifically Cepheid variables, with gas clumps to determine distances more accurately, revealing a highly flocculent and complex spiral structure that improves understanding of galaxy dynamics and dark matter distribution.

via Phys.org|

#atomic-hydrogen #cepheid-variables #galaxy-structure

science1 year ago•5 min saved

James Webb Telescope Unveils New Mysteries in Universe's Expansion

New data from the James Webb Space Telescope confirms previous Hubble Space Telescope measurements of the Universe's expansion rate, suggesting discrepancies with theoretical models may indicate new physics. The study, published in The Astrophysical Journal, supports the accuracy of Hubble's data, ruling out measurement errors and highlighting a tension between observed expansion rates and predictions from the standard LambdaCDM model. Theorists are now exploring explanations such as early dark energy or exotic particles to resolve this "Hubble tension."

via Ars Technica|

#cepheid-variables #hubble-constant #james-webb-space-telescope

astronomy2 years ago•8 min saved

Webb Space Telescope Unveils New Insights into the Hubble Constant Tension

The "Hubble Tension," which refers to the discrepancy between the observed and predicted expansion rate of the universe, remains a mystery. The James Webb Space Telescope (JWST) has provided new measurements to refine the Hubble constant, but questions persist about the universe's rapid expansion and potential underlying cosmic phenomena. Webb's infrared vision has allowed for more precise observations of Cepheid variables, which are used as distance markers, and has confirmed the accuracy of previous Hubble measurements. However, the cause of the Hubble Tension, whether it be exotic dark energy, dark matter, a revision to our understanding of gravity, or measurement errors, remains unknown.

via SciTechDaily|

#astronomy #cepheid-variables #cosmic-distance-ladder

astronomy2 years ago•8 min saved

"Webb's Confirmation Deepens Mystery of Hubble Constant Tension in Universe's Expansion Rate"

NASA's James Webb Space Telescope has confirmed the accuracy of the universe's expansion rate, known as the Hubble constant, and deepened the mystery of the Hubble Tension. The Hubble constant, which is crucial for understanding the evolution and fate of the cosmos, has shown a persistent difference between measured values and predictions from the big bang afterglow. Webb's observations of Cepheid variables, reliable distance markers, have significantly reduced noise in the measurements and confirmed the accuracy of previous Hubble measurements. The discrepancy in the expansion rate suggests the presence of exotic dark energy, dark matter, a revision to our understanding of gravity, or the presence of a unique particle or field. The mystery of the Hubble Tension continues to deepen.

via Phys.org|

#astronomy #cepheid-variables #hubble-constant

astronomy2 years ago•7 min saved

Unveiling the Expanding Universe: JWST Data Deepens Hubble Tension

New data from NASA's James Webb Space Telescope (JWST) has confirmed and intensified the "Hubble tension," a discrepancy between two different methods of measuring the expanding rate of the universe. The JWST observations of Cepheid variable stars in nearby galaxies, combined with measurements of type Ia supernovae, have reduced uncertainties and validated previous findings from the Hubble Space Telescope. The data suggests that the expansion rate is around 67 km/s/Mpc, in contrast to the value of 73 km/s/Mpc obtained from the cosmic distance ladder method. The discrepancy deepens the mystery surrounding the true expansion rate of the universe.

via Big Think|

#astronomy #cepheid-variables #cosmic-distance-ladder