How many stars in the universe
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Estimating the Total Number of Stars in the Universe
Introduction to Star Count Estimations
The vastness of the universe has always intrigued humanity, leading to numerous attempts to estimate the total number of stars. While the stars visible to the naked eye are limited, advanced astronomical techniques have provided more comprehensive estimates.
Photometry-Based Estimations
A novel approach to estimating the total number of stars in the universe involves 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 6×10²²1.
Observations from the Milky Way
Within our own galaxy, the Milky Way, there are estimated to be a few hundred billion stars of various ages, sizes, and masses7. This vast number is a small fraction of the total stars in the universe, considering the multitude of other galaxies.
The Scale of the Universe
The universe contains millions of galaxies, each with billions of stars. For instance, it is estimated that there are about 100 billion stars in our galaxy alone, and another 100 billion galaxies in the universe5 6. This immense scale makes the total number of stars in the universe staggeringly large.
Cataloging Stars
Efforts to catalog stars have resulted in extensive databases. For example, the Optical Gravitational Lensing Experiment (OGLE) project has identified nearly 66,000 Mira-type variable stars in the Milky Way3. Additionally, a reference work contains data on the magnitudes of more than 100,000 stars in the galaxy4.
Conclusion
In summary, the total number of stars in the universe is estimated to be around 6×10²², based on photometry-based methods. This estimate is supported by observations of the Milky Way and the vast number of galaxies in the universe. The continuous advancements in astronomical techniques and cataloging efforts contribute to our understanding of the universe's immense scale.
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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.
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.
Me, Myself, and the Universe
When you look up in the night sky, you see stars. Hundreds, thousands of them, glimmering and glistening, each and every one bigger and brighter than our own sun. A hundred billion stars lie in our galaxy, and another hundred billion galaxies in our universe. Our minds are unable to comprehend how large the universe really is.
Astronomy with the Naked Eye
The Sun is a relatively insignificant star in a relatively insignificant galaxy, the Milky Way, and our understanding of the universe is based on the knowledge of the universe from an unprivileged point of view.
STELLAR EVOLUTION AND THEIR ASTRONOMICAL OBSERVATIONS
Stars undergo various evolutionary phases, with some ending in catastrophic explosions, and multi-wavelength observations are crucial for understanding their laws of physics and their impact on the evolution of the Universe.
Empty Space
Extragalactic space is believed to be empty, but in interstellar space, electrons, protons, atoms, gas molecules, and larger matter exist.
Highly CitedA spectroscopic survey on the multiplicity of high-mass stars
High-mass stars form close binary systems, with a majority (>82%) forming close pairs with similar mass, supporting a multiplicity originating from formation rather than tidal capture in dense clusters.
Highly CitedThe Formation of the First Star in the Universe
At most one massive metal-free star forms per pregalactic halo, with radiation feedback inhibiting star growth and preventing further star formation in the same pregalactic object.
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