How many stars in the observable universe

Pro Research Analysisby

Searched over 200M research papers

Analyzed relevant papers

Estimating the Number of Stars in the Observable Universe

Introduction to Star Count Estimations

The observable universe is vast, containing an immense number of stars spread across billions of galaxies. Estimating the total number of stars involves complex methodologies and astronomical observations. This article synthesizes recent research to provide an understanding of how many stars exist in the observable universe.

Photometry-Based Estimations

A novel approach to estimating the total number of stars in the universe uses photometry-based methods. This technique relies on the energy conservation law and measurements of extragalactic background light levels. By assuming that every radiated photon remains within the universe, researchers have estimated the total number of stars to be approximately 6×10²² .

Galaxy-Based Calculations

Another method involves calculating the number of stars based on the number of galaxies and the average number of stars each galaxy contains. Observational evidence suggests there are about 100 billion galaxies in the observable universe, with each galaxy containing roughly 100 billion stars on average 58. This leads to an estimated total of 10²² stars, aligning closely with the photometry-based estimation.

Specific Star Catalogs and Observations

Detailed star catalogs, such as the OGLE project, provide insights into specific types of stars within our galaxy. For instance, the OGLE project has cataloged nearly 66,000 Mira-type variable stars in the Milky Way . While these catalogs focus on specific star types and regions, they contribute to the broader understanding of star distribution and density within galaxies.

Conclusion

Combining various estimation methods, including photometry-based calculations and galaxy-based averages, researchers consistently estimate the number of stars in the observable universe to be around 10²². This immense number underscores the vastness of the cosmos and the complexity involved in astronomical measurements and estimations.

Sources and full results

Most relevant research papers on this topic

Photometry-based estimation of the total number of stars in the Universe.

The total number of stars in the Universe is about 61022, based on energy conservation law and extragalactic background light levels.

2015·

7citations

·L. Manojlović

Applied optics

The Number and Light of the Stars

The number of stars visible to the naked eye on a clear night is roughly 5,000, but astronomers are now using this data to better understand the structure of the sidereal universe.

1914·

0citations

·S. Chapman

Nature

The OGLE Collection of Variable Stars: Nearly 66,000 Mira Stars in the Milky Way

The OGLE database contains 65,981 Mira-type variable stars, with most new discoveries, and can be used as a training set for machine-learning classification algorithms.

2022·

12citations

·P. Iwaneket al.

The Astrophysical Journal Supplement Series

Catalogue of Mean UBV Data on Stars

This work provides a comprehensive reference for identifying and measuring the visual magnitude of over 100,000 stars in the galaxy, based on photoelectronic measurements from 1953 to 1992.

Highly Cited

1994·

73citations

·J. Mermilliodet al.

Gamma-Ray Emission of Active Galaxies

The observable universe consists of billions of galaxies, many of them containing 100 billion or more stars, like our “Milky Way” for example. On a morphological basis these galaxies are grouped into three main categories: spirals, ellipticals, and irregulars.

2001·

3citations

·W. Collmar

A new reference catalogue for the very metal-poor Universe: +150 OB stars in Sextans A

This study has produced the largest catalog of OB-type stars at sub-SMC metallicities, revealing evolutionary pathways and fates of very metal-poor massive stars in an environment analogue to the early Universe.

2022·

6citations

·M. Lorenzoet al.

Monthly Notices of the Royal Astronomical Society

Empty Space

Extragalactic space is believed to be empty, but in interstellar space, electrons, protons, atoms, gas molecules, and larger matter exist.

Highly Cited

1941·

157citations

Nature

Hydrodynamics, Vortices and Angular Momenta of Celestial Objects

Non-irrotational hydrodynamic flow in the universe can explain the formation of large numbers of galaxies and stars, indicating a primordial rotation broken up into vortex line structures.

2011·

58citations

·C. Sivaramet al.

arXiv: General Physics

The Massive Star Population of Cygnus OB2

Cygnus OB2 is one of the most massive groups of young stars known in our Galaxy, with 169 primary OB stars and a total mass of 16500 +38002800 M.

Highly Cited

2015·

89citations

·N. Wrightet al.

Monthly Notices of the Royal Astronomical Society

The first stars in the Universe

The first observable star likely formed 30 million years after the big bang, and the first galaxy as massive as our Milky Way likely formed when the Universe was only 400 Myr old.

Highly Cited

2006·

84citations

·S. Naozet al.

Monthly Notices of the Royal Astronomical Society: Letters

Try another search

can you see a black hole with a telescope

weird facts about black holes

hives photos

inner ear problems

earache causes ear pain

how strong is a black holes gravitational pull